Virology in Schoolbooks—A Comprehensive Analysis of Austrian Biology Textbooks for Secondary School and Implications for Improvement

Abstract

Virology has gained much attention in recent years due to the COVID-19 pandemic and other recurrent epidemics/pandemics such as Ebola, zika, or now, monkeypox. We have analysed all recent biology schoolbooks for secondary school approved for the Austrian market. Our aim was to find out whether virological content was presented comprehensively, comprehensibly, and in an error-free manner. This also relates to visual representations of viruses, processes related to virology (e.g., replication), and references to daily life. Furthermore, we looked for tasks related to virology that may help students to deepen their newly acquired knowledge and/or to put it into practice, either by hands-on experimentation or transfer tasks. We examined 97 books (76 books for lower secondary and 21 books for upper secondary school). For this analysis, we developed and tested a coding matrix accompanied with a comprehensive coding guide to facilitate reproducible and reliable ratings. Since inter-rater reliability was found to be very high, both the coding matrix and guide can be recommended for further studies in this field. Overall, the virological content provided was free of errors, with the text and illustrations being mostly comprehensive and comprehensible. This was expected, since all Austrian school books must be approved by a governmental commission. However, individual books even for the same target (age) group differed widely in content and detail. In particular, few books clearly differentiated between viruses and bacteria, clarified that viruses are non-living and emphasized that antibiotics are ineffective against viruses. Yet precisely such knowledge is essential to enable students to make scientifically based decisions in health-related situations, especially for the prevention and treatment of viral diseases (e.g., whether to take antibiotics when suffering from a viral disease).

1. Introduction

The last few years have drastically shown that deadly viral diseases are not gruesome stories from the past, related to specific behaviour, or restricted to specific regions. On the contrary, the COVID-19 pandemic has probably had physical, mental, economical, and/or social impacts on most people worldwide. The causal agent of viral diseases—viruses—are non-living particles very distinct from living organisms and even bacteria, although they are often misleadingly placed under the heading “micro-organisms” and understood by many as a kind of unicellular living being [1,2]. Viruses display a wide variety of structures, with some viruses even making use of host cell membrane components; for replication, they depend on host cells, which can be any living organism, though individual viruses may be very host-specific [2]. The wide occurrence of viruses, their significance as pathogens, and their very special organization make them an interesting and important topic at school. Therefore, the time has come to examine the place virology finds in schoolbooks, since such books are an essential source of information for a large part of the population in many countries.

This is even more important as what we learn about viruses at school may help us to:

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Understand what viruses really are, e.g., non-living particles, which is biological knowledge that is valuable on its own, but also highly relevant for everyday situations (see next points).

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Counter fake news, e.g., the belief that viruses causing measles or COVID-19 do not exist but are an invention of politicians and the pharmaceutical industry; that they are harmless, and their danger is exaggerated by governments and industries; and that they may be killed off by antibiotics [1,2,3,4,5,6,7,8,9,10].

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Realise how we can protect ourselves and others against viral infections, which is an important issue both for individual well-being and public health. Therefore, students should become familiar with the transmission routes of the (regionally) most important viruses and learn how to protect themselves against an infection.

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Raise awareness for and develop new therapies against viral (e.g., antiretroviral medication against HIV) as well as bacterial diseases (e.g., phage therapy). In this respect, it is important that students learn about the essential steps of viral replication, at least basically, to be able to understand why and where antiviral medication can target this process and thereby prevent the further production of viral particles.

Naturally, the knowledge presented and discussed in schoolbooks must not contain content or wording/phrasing-related mistakes, as both may create misconceptions and/or lead to the memorisation of wrong ‘facts’ (e.g., naming viruses as micro-organisms or incorrectly labelling structures shown in illustrations).

However, there are only very few studies analysing in depth what students know about viruses [1,11,12,13]. Yet Dumais and Hasni (2009) rightly stated that “understanding the conceptions that young people have about viruses […] may be important for the development of effective school health education programs” ([11] p. 62). In this respect, schoolbooks as a knowledge source seem to have been overlooked completely when it comes to virology.

In this paper, we aim to show why information about viruses presented in biology schoolbooks may be important to raise the virology-related knowledge level of the population and thereby improve the understanding of the measures for preventing future pandemics. We show and discuss data from a thorough analysis of Austrian biology textbooks from secondary school and suggest means for improvement. Furthermore, we link our results to the DARAHM model (Determinants of the ability to reflect and act on health matters), recently presented by the German–Swiss–Austrian Working Group “Gesundheit & Biologie” (Health and Biology) [14].

1.1. Virology in the Austrian Curriculum

The Austrian school system is broadly divided into primary school (grade 1–4), lower secondary school (grade 5–8; either middle school or high school), and upper secondary school leading to A-levels (grade 9–12/13, depending on the type of high school). The counting scheme begins anew after primary school. Thus, students in grade 5 start secondary school with class 1 again, which is reflected in schoolbook labelling.

In Austrian lower secondary school, virus-related topics may be discussed in class within the thematic field “Mankind and health”, mainly in grades 6 and 8. Virology is only once referred to specifically in the curriculum, namely in grade 8, where AIDS (acquired immune deficiency syndrome) is explicitly mentioned as a disease to be discussed. In upper secondary school, viruses may be integrated in topics such as “differences between pro- and eukaryotes” in grade 9 (if teachers want to deliver such knowledge), “immunology and diseases” in grade 10 (again, AIDS is explicitly mentioned here), “pathogens” and “infectious diseases” (with an explicit naming of viruses) in grade 11 (however, only few schools teach biology in grade 11; thus, these topics are either omitted or dealt with in grade 10 or 12 in a condensed version), and “biotechnology” in grade 12 (often, gene therapy is included here) [15,16]. There is no reference to virology in primary school, neither in the curriculum nor in schoolbooks for these grades. Therefore, we restricted our analyses to books for secondary school.

To summarize, viruses are rarely mentioned in the curriculum, which offers little stimulation for schoolbook authors to deal with them in detail in their books. On the other hand, there are several thematic fields that would allow the inclusion of virology.

1.2. The Impact of Schoolbooks on Knowledge and Attitude of Students

Besides speech and graphical representations, written texts are probably among the most important and most traditional tools to convey knowledge, starting from ancient papyrus scrolls to modern books, nowadays supplemented or replaced by e-books, online material, or other electronic texts. Yet, as Heynemann (2006) stated, “textbooks (…) will remain an instrument of extraordinary power. They may (…) be the most effective of educational technologies yet invented, and there is no reason to imagine a modern educational system where textbooks do not play a central role.” (p. 36 [17]).

Text and information in schoolbooks are compiled and designed by the authors and editors with the intention that students encounter the knowledge deemed essential for their future life, with such knowledge often being listed in national or regional curricula. Thus, schoolbooks are typically written to assist students in learning what a particular school authority believes to be crucial for the general population to possess. This is especially true for countries such as Austria, where all schoolbooks are acquired by schools through a fund of the ministry of education and have been reviewed and approved of by schoolbook commissions specifically staffed with subject-specific experts according to national curricula. (Approved schoolbooks are free of charge in Austria.)

On the other hand, schoolbook texts may also influence attitude formation in those reading them. Political influence may have the consequence that the same schoolbook may be published in different versions—even within the same country—if commissions of certain states differ in what they want their students to read. A prominent example comes from a New York Times analysis comparing U.S. history schoolbooks with special editions for California and Texas [18].

Depending on such authorities’ level of independency, schoolbooks may thus contain subliminal or openly declared attitudes and prejudices concerning specific topics, countries, groups of people, etc. One may think that such attempts to steer readers towards a certain political direction may particularly relate to history, geography, politics, or religion/ethics. For example, many early U.S. history textbooks have conferred anti-British feelings [19]. A more recent example comes from the analysis of schoolbooks for religion, ethics, history, Arabian, and social studies in Afghanistan, Iran, Egypt, Palestine, and Turkey [20]. In these books, the author found conspiracy theories and antisemitism, the control of religious thinking and behaviour, nationalism, and the streamlining of national histories.

However, examples for trying to imprint a certain political (or religious) agenda can also be discovered in the natural sciences and mathematics. For example, creationism found its way into many former biology schoolbooks in the U.S., even though more recent books seem to have mostly expelled this religious concept from biology teaching [21]. Another example comes from a math book from the former German Democratic Republic: “36 German, 25 Soviet and 15 Polish pioneers take part in the friendship meeting. How many pioneers are celebrating together?” [22]. On the surface level, this is a simple calculation task. Yet there are several political messages transported, too: First, this task relates to pioneers, which were members of a scout-like organization training pupils according to the respective socialist government’s political views and making them contribute to society in social projects. When embedded in a math task, pioneering is transported as something normal. Second, young readers learn that there are pioneers in other socialist countries, which had been political allies of former East Germany. Thus, political bonding may be formed between students from these countries.

Apart from hidden or openly conferred political, moral, or religious messages, the kind of knowledge presented in a schoolbook is also important, as well as the degree of detail. For instance, the way students understand inheritance and genetics may well be influenced by how strongly a textbook emphasizes genetic determinism and how the interrelation between genotypes and phenotypes is discussed [23].

Although there are apparently very few studies that have analysed the impact of schoolbooks on students’ knowledge formation, there is some indication that schoolbooks are not only widely and consistently used in the classroom, but that they may additionally function as a source for information both for students and parents at home [24,25,26,27], although some authors have found that schoolbooks are only used inside school [28]. For biology, the importance of schoolbooks as a source of knowledge and interest is demonstrated in a pilot study by Aufdermauer and Hesse (2007), in which 44% of the participating middle school students stated that they would make use of their biology textbook even in their leisure time, while more than a third had tried out experiments described in the book at home [29]. For math, some authors have found that the specific schoolbook chosen by teachers may influence both the content and methodology of teaching [30]. One must concede, though, that on the individual level the influence and use of schoolbooks may very much depend on students’ training in self-learning, on their teachers’ background and skills in information presentation and discussion (and, if needed, in scaffolding according to individual students’ needs), the attitude and background of parents, and the use and opinion of a specific book by peers.

1.3. Schoolbooks, Virology, and the DARAHM Model

As explained above, schoolbooks and the knowledge presented therein may influence students’ and parents’ knowledge about a particular topic and their attitude towards that topic. This may also hold true for teachers relying on schoolbooks as the main or only knowledge/attitude source for their subject. Furthermore, one’s predisposition and preconceptions may play important roles here. For example, the acceptance of factual knowledge about specific diseases, their causal agents, and preventive measures such as vaccination presented in schoolbooks may come into conflict with conspiracy theories, esoteric beliefs, certain religious views, general fears concerning specific technologies (e.g., genetic engineering), or general scepticism against science. Thus, students may hear from their parents that certain diseases are, in fact, an invention by certain groups and/or that their causal pathogen does not exist in reality (see above). Here are three examples: (i) Kindergarten children in the U.S. have been found to be less likely to have received vaccination against measles, mumps, and rubella (MMR) and diphtheria, tetanus, and pertussis (DTaP) in states allowing exemption due to religious or philosophical reasons [31]; (ii) Some anti-COVID-19-vaccination campaigners used the court case of a German ‘biologist’ denying the existence of the measles virus for implicitly arguing against vaccination against COVID-19 (discussed in [2]); (iii) in a small-scale pilot study in the German state Baden-Wurttemberg, three of the seven interviewed biology teachers said that many parents were against vaccination [32]. It may be a coincidence, but this state is the centre of the anthroposophical movement in Germany, and there is some indication that belief in non-evidence-based treatments (such as homeopathy) and the refusal of COVID-19 vaccines are significantly correlated [33].

Second, the acceptance of measures for treatment of viral diseases and the prevention of their transmission may also be influenced by parental views, role models, and other influential voices such as state representatives; whether or not a disease is taken seriously and whether sensible measures are followed may strongly depend on public statements of politicians and their coherence, as could be seen during the current COVID-19 pandemic, where some state leaders publicly denounced vaccination or even the existence of the virus, recommended the use of antibiotics or ivermectin, or declared vaccines produced in countries of other political systems to be inefficient without any scientific proof.

Third, electronic media probably play an important role in knowledge acquisition and attitude formation. As polls from the U.S. have shown, most people with access to the internet, especially younger users, would try to find information on a specific scientific topic on the internet first [34].

All this shows that school is but one of the many factors students are exposed to. These factors (or settings) are part of the DARAHM model recently introduced into health education [14]. This model focuses on the empowerment of students to act according to their (perceived) best interests in health-related situations. The model is built upon inner and outer concepts, which are closely intertwined: the centre of the model is the individual “self”, which includes how one sees oneself in relation to one’s health and in general, the ability to reflect about one’s own attitudes, intentions and behaviour, and one’s own impression of self-efficacy; here, three aspects should be heeded, namely, cognition (e.g., acquired knowledge), motivation/affection (e.g., personal interest and beliefs), and performance (e.g., knowledge put into practice). Yet every individual experience is influenced by its surroundings. This is mirrored in the model in that the centre (the “self”) is surrounded by two “settings”: “school” (as the setting of particular interest for educators this model is made for) and “other settings”. The latter refers to family, friends, role models, media, local or other communities, etc. The DARAHM model is not meant as something static. On the contrary, both the self, school, and the other settings are in constant exchange and influence each other [14].

In relation to the way schoolbooks are used as a source for knowledge and attitude formation, the DARAHM model can be understood in a way that such a usage can be influenced by several players, as discussed above. For example, teachers must select and use specific books, and these books may deliver different or differently detailed content and, implicitly or explicitly, different attitudes, which in turn may depend upon individual authors and/or school authorities. On the other hand, parents may have explicit attitudes to certain content dealt with in such books and/or may use such books for their own knowledge building. Students, being influenced by their family, peer groups, role models and others, may or may not accept scientific facts and recommendations presented in their schoolbooks. However, well-written and designed books and the well-prepared usage of them by teachers may not only foster learning but lead to conceptual changes in case of conflicting concepts (e.g., parental refusal of vaccination vs. positive representation of vaccination in a schoolbook).

Thus, the “other settings” mentioned in the DARAHM model [14] may have a positive, negative, or neutral effect on the reception of information gathered at school and from schoolbooks. However, individual teachers play a very important role here, both in the way schoolbook (and other) knowledge is selected, structured, and prepared for a possibly heterogeneous group of learners and in the way both teachers and, presumably, books are perceived as subject authorities by their students [35]. Nevertheless, to allow students to acquire, evaluate, and apply knowledge on their own by reading a textbook, decisive facts concerning a given topic should be presented in a comprehensible manner that is detailed and appealing enough to facilitate understanding and not just knowledge reproduction. Consequently, schoolbook authors should:

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Provide up-to-date scientific knowledge (e.g., what a virus is, how it is different from living organisms, how a virus is replicated and transmitted, and how vaccination and medication may interfere with viral replication by the priming of the immune system or by blocking receptors or enzymatic steps in the replication process);

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Make suggestions for implementation in real life (e.g., preventive measures and treatment);

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Deliver clear-cut arguments against myths (such as “viruses are killed by antibiotics”) by making use of scientific facts (e.g., viruses have no metabolism with which antibiotics could interfere with);

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Aid understanding by multiple but interconnected representations (e.g., visual representation of the replication process);

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Make suggestions for exercises to facilitate both long-term knowledge storage and knowledge transfer (theoretical tasks) and behavioural routines (e.g., handwashing, boiling water for the preparation of meals, avoiding contact with blood from other persons, and so on).

This, in turn, may allow students to develop knowledge and, subsequently, knowledge-based behaviour that is in accordance with the present scientific view.

Yet, the COVID-19 pandemic has drastically shown that many people have lost trust in science due to contradicting views by experts. For example, even leading virologists in German-speaking countries disagreed about when to implement certain measures and how strictly these measures were to be followed. Here, it is important to discuss with students that the formation of knowledge in science is no clear-cut and streamlined process. Instead, it is highly discursive and includes comparing new insights, testing and discussing new results, and, possibly, overthrowing hypotheses and theories held true until a given contemporary period. Teaching about the nature of science, including its process of knowledge discovery, may help students to better come to terms with the complexity of science in later life [36]. In schoolbooks, this could be reflected in the presentation and discussion of different perspectives on the same topic, or the delineation of how a certain scientific discovery was made, including discoveries that were originally not believed in even by experts of the field (e.g., that human papilloma viruses are the main cause for cervical cancer). However, this latter approach would require a different and more argumentation-based schoolbook analysis and has therefore not been included here.

2. Method

We analysed all Austrian biology schoolbooks for lower and upper secondary schools, which were officially approved by the Austrian ministry of education, with latest editions not older than ten years. The full list of analysed books can be found in Supplementary Material S1 In total, 97 books were examined, with 76 books for lower secondary and 21 books for upper secondary (with only one for grade 11—in this grade, biology is usually taught only in profession-oriented/vocational high schools). Since many students leave school after lower secondary [37], there are far fewer books for upper secondary than for lower grades.

To facilitate analysis, all pages with virus-related content were scanned by the first author after screening all books. These scans were then used by all authors for comparative analyses.

For better comparison and empirical foundation, we developed a matrix for the analysis of the virus-related content in schoolbooks (Supplementary Material S2). Five main categories were designed:

(1)

Content—What kind of knowledge is presented, and in what degree of detail and length?

(2)

Illustrations—How many and what kind of figures, tables, etc., can be found, and what is their quality?

(3)

Language—How many and which scientific terms are used?

(4)

Exercises and Relevance—How many and what kind of exercises are present? How relevant to daily life is the content presented?

(5)

Special Notes. (This category was not included in inter-rater reliability calculations, as it was too subjective.)

The rationale behind these categories was the following:

Content: The absolute and relative space a certain book allocates to virology (chapters, pages, and paragraphs) may provide an indication of how important this topic is to the authors and, generally, to what degree of detail virology is dealt with. The subcategories for this category in Supplementary Material S2 were agreed upon by all authors, mostly based on findings from [1,10]. For example, results from these studies indicated that several pupils and adults had difficulties distinguishing between viruses and bacteria and the diseases they may cause, had little or no understanding of the basic replication process of viruses in the host cell and the way vaccination functions, and did not realize that antibiotics are ineffective against viruses. Furthermore, several participants in these studies had asked whether viruses were only “bad”, or whether there were “good” viruses, too [1,10]. Other categories were included because they addressed important measures to avoid or at least reduce infection and are specifically referred to in the Austrian curriculum (e.g., prophylactic hygiene measures, vaccination, immune system, and immunization) [15,16] and because earlier studies had shown that many people do not fully understand the way vaccination and related immunological processes work and did not know against which diseases vaccines are available [1,10]. Accordingly, books were checked with respect to whether these aspects were addressed. Concerning replication, this is an important aspect in virology, both for its biological interest and because it provides possibilities for treatment (e.g., preventing binding to receptor molecules). Therefore, graphic illustrations of replication were additionally examined in greater detail. Finally, we checked for content-related mistakes. Identification of such mistakes was based on school knowledge, on knowledge acquired during the authors’ studies (all biological backgrounds), and—in case further checking was required—on using various internet resources and virology textbooks.

Illustrations: Usually, schoolbooks employ many illustrations to make the content more attractive and to facilitate understanding by visually representing complex processes. The subcategories for this category in Supplementary Material S2 were agreed upon by all authors. It was the intention to cover a broad spectrum of representations (e.g., pictures of viruses or disease symptoms, graphs, and tables) to thoroughly analyse how much information, if any, was delivered in a format other than text. Second, illustrations were checked for content mistakes and completeness (e.g., whether the replication cycle was displayed in full or only partially). Then, labels were examined, because good labelling may aid understanding of the structure/process shown, while unlabelled or incorrectly labelled structures/parts may hinder understanding or even create misconceptions.

Language: Apart from illustrations, language may play an important role in science education and in the understanding of science concepts. The Austrian curricula for secondary school explicitly demand introducing students to scientific language [15,16]. On the other hand, too many scientific terms may make reading and understanding too difficult for many students [38]. Thus, we examined how many and which scientific terms each book contained in relation to virology. The subcategories for this category in Supplementary Material S2 were agreed upon by all authors.

Exercises and Relevance: In this category, our analyses were based on task types typically used in Austrian schools, which comprise (i) searching for information and (ii) using this information in a related task to deepen this newly acquired knowledge, (iii) evaluating information and transferring knowledge to other fields (including the ability to develop recommendations), and (iv) practical work, such as experimentation or using simulations. Furthermore, relevance is an important factor for creating and holding interest [39,40]. Consequently, all books were scrutinized to determine whether they attempted to show their readers how the virological content presented relates to their own life. Again, the subcategories for this category in Supplementary Material S2 were agreed upon by all authors.

Special notes: Here, specific comments of individual raters can be noted to highlight specific points of interests (e.g., whether a book and the virological content within was deemed particularly attractive, and why).

To facilitate comparison between books, the coding matrix was designed such that presence or absence and the amount of specific subcategorial content could be noted (depending on the type of content analysed). Then, more detailed information including at least one example was to be inserted. Finally, the matrix leaves room for notes for each subcategory.

After a first trial with one grade-12 biology book (final year of high school) performed independently by all authors, the original matrix was slightly altered for reasons of simplification and clarity, and a supporting coding guide was developed (Supplementary Material S3). The same book was used for a second independent rating with this adopted matrix, results were compared, and the altered matrix was found to improve congruence greatly. After some additional minor adjustments agreed upon in discussion between all three authors, NH and SL independently analysed six further books for calculation of interrater reliability with SPSS. ICC values for each category were between 0.615 and (mostly) 1.0 and Cronbach’s alpha was between 0.762 and (mostly) 1.0; thus, these values were deemed sufficiently good (Supplementary Material S4). Therefore, all subcategories were defined well enough to yield acceptable reliability and no change or deletion of individual subcategories were necessary. Therefore, all other books were subsequently analysed by NH alone.

3. Results

The results are presented according to the order of (sub)categories in the coding matrix (Supplementary Material S2), with the results for some subcategories being summarized (e.g., subcategories C. 1.3–C 1.7).

Overall, 81 out of the 97 analysed books provided some or even in-depth virological knowledge. A total of 16 books had no references to viruses at all. The latter were all made for grades 5 or 7, in which viruses or other health-related topics are not explicitly listed in the curriculum.

Table 1. Average extent of virology in the analysed schoolbooks. Books without any virus-related content at all are not listed.

Grade	Total Pages	Pages with Virus-Related Content	Average	Percent	Average
5	128–160	0.1–0.5	0.26	0.07–0.35%	0.26%
6	64–168	0.1–3	0.49	0.07–2.14%	0.37%
7	64–152	0.1–0.2	0.15	0.07–0.31%	0.14%
8	64–176	1.3–8.3	4.48	1.33–4.94%	3.28%
9	160–216	0.2–2.3	0.83	0.13–1.20%	0.43%
10	168–256	3.7–4.7	4.95	1.84–3.69%
11	128	10.8		8.44%
12	144–200	1.5–6	4.13	0.87–3.82%	2.55%

shows the average extent of the content related to virology in the analysed schoolbooks for each grade, both in absolute numbers (pages) and in the percent of the total number of pages. A detailed version of this table can be found in Supplementary Material S5.

3.1. Occurrence of Specific Viruses/Virus Groups

Table 2. Single viruses, informal (e.g., “plant virus”), and taxonomic (e.g., “adenoviruses”) virus groups named in the analysed schoolbooks (numbers represent frequencies). Viruses which may infect humans are printed in italics.

Virus/Virus Groups	Lower Secondary	Upper Secondary	Total
Adenoviruses	1	3	4
Animal viruses	13	7	20
Avian influenza viruses	1	1	2
Avian virus	1	2	3
Bacteriophages	1	8	9
Bacteriophage T1	0	1	1
Bacteriophage T2	0	2	2
Bacteriophage T4	0	1	1
Cauliflower mosaic virus	0	1	1
Cold virus	2	2	4
Coronavirus	1	0	1
Cowpox virus/Vaccinia virus	0	2	2
Cytomegalo virus	0	3	3
Dengue virus	0	1	1
Dependovirus	0	1	1
DNA viruses	0	2	2
Ebola virus	2	2	4
Enteroviruses	0	1	1
Epstein–Barr virus	1	2	3
Flu virus/influenza virus	16	15	31
Foot and mouth disease virus	4	0	4
H1N1	0	3	3
H2N2	0	2	2
H3	0	1	1
H3N2	0	1	1
H5	0	1	1
H5N1 virus	0	2	2
H7	0	1	1
Hantaviruses	1	0	1
Hepadnaviruses	0	1	1
Hepatitis-A virus	4	3	7
Hepatitis-B virus	12	8	20
Hepatitis-C virus	6	5	11
Hepatitis-D virus	0	1	1
Hepatitis-E virus	0	1	1
Hepatitis viruses	3	1	4
Herpes-simplex virus	0	3	3
Herpes-simplex virus HSV1	0	1	1
Herpes-simplex virus HSV2	0	1	1
Herpes viruses	4	7	11
Herpes virus HV8	0	1	1
HIV	21	16	37
Human T-cell-leukaemia virus/HTLV	0	1	1
Human papilloma viruses/HPV	11	11	22
Human pathogenic virus	0	2	2
Influenza Type A virus	0	3	3
Influenza Type B virus	1	1	2
Influenza Type C virus	1	1	2
Marburg virus	0	1	1
Measles virus	15	6	21
Mimivirus	0	1	1
Mumps virus	9	5	14
Myxomatosis virus	0	3	3
Orthomyxoviruses	0	1	1
Papovaviruses	0	1	1
Parainfluenzaviruses	0	1	1
Paramyxoviruses	0	1	1
Parvoviruses	0	1	1
Picornaviruses	0	1	1
Plant viruses	0	1	1
Poliomyelitis viruses	14	3	17
Pox viruses	5	4	9
Rabies virus	4	2	6
Retroviruses	0	9	9
Rhabdoviruses	0	1	1
Rhinoviruses (cold viruses)	5	6	11
Rhizomania virus	1	0	1
RNA-Viruses	0	6	6
Rotavirus	1	1	2
Rubivirus/rubella virus	11	4	15
Swine flu virus	0	1	1
Swine pest virus	1	0	1
Swine viruses	0	1	1
Tobacco mosaic virus	0	1	1
Togaviruses	0	1	1
Varicella-Zoster virus/Chickenpox virus	5	3	8
Virus (generic)	26	20	45
Yellow fever virus	0	1	1
Zika virus	0	2	2

lists all virus names/virus groups found in the analysed books, with at least one specific virus mentioned in 37 books of the lower and all the books of upper secondary levels. The following viruses were dealt with particularly often:

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Tick-borne encephalitis virus (TBE), a very prominent virus in Austria, against which the government regularly warns the populace through the media, including the recommendation to get vaccinated.

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Influenza virus—as in many countries, an important cause for illness and even death (mainly among the elderly) in the winter season; vaccination is recommended but is only partially efficient.

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Hepatitis viruses, in particular hepatitis B, one of the most widespread infectious diseases against which vaccination is available.

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Human immunodeficiency virus (HIV)—the causal agent of AIDS, which is deadly without (expensive) therapy, and with no vaccination available. It is the most often-discussed sexually transmitted disease in German-speaking countries and the only viral disease explicitly mentioned in Austrian curricula for biology.

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Measles, mumps, rubella, poliomyelitis viruses—explicitly mentioned in the Austrian children vaccination schedule (as are hepatitis B and rotavirus) [41].

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Human papilloma viruses (HPV)—the main cause for cervical cancer; vaccination is recommended in Austria and is free of charge for children aged between 9 and 12 years [42].

A total of 33 books (for grades 8–12) named five or more different viruses. A total of 67 references were found to viruses (e.g., Dengue virus) or virus groups (e.g., enteroviruses) that (potentially) infect humans.

3.2. Definition and Structure of Viruses

The structures of the viruses were described in 27 books (13 lower and 14 upper secondary) and their sizes in 26 books (11 lower and 15 upper secondary). Only 24 books (25%) explicitly stated that viruses are non-living. Exactly half of those were for the lower secondary level (mostly grade 8), and the other half were for upper secondary (mostly grade 12). All other books had no such clear-cut delineation of viruses from living organisms. A total of 29 books (18 lower and 11 upper secondary) pointed out differences between viruses and bacteria. Only 12 books (12%; 9 lower and 3 upper secondary) clearly stated that antibiotics are ineffective against viruses.

3.3. Viral Diseases

The various diseases caused by viruses were described in 79 books (59 lower and 20 upper secondary), of which 60 presented at least one disease in detail (46 books for lower and 14 books for upper secondary). In total, 66 different viral diseases were referred to; 40 in lower and 66 in upper secondary books. (Variations in naming the same disease were counted as one.) A total of 35 diseases were explained in detail in at least one book (

Table 3. Viral diseases found in the analysed schoolbooks, sorted by frequency. (Note: Sometimes, schoolbook authors have mixed diseases and symptoms, e.g., “coughing”.)

Disease	Occurrence in Lower Secondary Books (Frequency)	% Lower Secondary Books	Occurrence in Upper Secondary Books (Frequency)	% Upper Secondary Books	Detailed Description (Lower Sec.) (Frequency)	Detailed Description (Upper Sec.) (Frequency)
Influenza	28	37%	15	71%	10	1
AIDS	25	33%	16	76%	23	7
TBE	30	39%	9	43%	16	3
Cold	24	31%	14	67%	7	3
Rabies	22	29%	9	43%	10	2
Hepatitis	16	21%	11	52%	13	1
Measles	18	24%	9	43%	10	2
Rubella	17	22%	7	33%	6	1
Pneumonia	17	22%	5	24%	9	1
Cancer	9	12%	12	57%	1	2
Mumps	13	17%	8	38%	7	2
Poliomyelitis	14	18%	6	29%	9	0
Cervical cancer	9	12%	10	48%	1	1
Hepatitis B	11	14%	7	33%	4	0
Warts	11	14%	6	29%	6	0
Chicken pox	10	13%	6	29%	4	1
Cold sores	10	13%	4	19%	5	0
Pox	7	9%	6	29%	3	0
Bronchitis	9	12%	2	10%	4	0
Hepatitis C	8	11%	2	10%	0	1
Food-and-mouth-disease	9	12%	1	5%	4	0
Cirrhosis of the liver	6	8%	3	14%	3	1
Shingles	4	5%	3	14%	1	1
Hepatitis A	4	5%	3	14%	0	0
Herpes genitalis	3	4%	3	14%	3	0
Cowpox	4	5%	2	10%	0	0
Liver cancer	2	3%	4	19%	0	0
Ebola	2	3%	3	14%	0	0
Leukaemia	0	0%	5	24%	0	0
Spanish flu	2	3%	3	14%	0	0
SARS	2	3%	2	10%	1	0
Swine fever	1	1%	3	14%	0	0
Dengue fever	0	0%	3	14%	0	0
Yellow fever	0	0%	3	14%	0	0
Hongkong-flu	2	3%	1	5%	0	0
Coughing	2	3%	1	5%	0	0
Kaposi’s sarkoma	0	0%	3	14%	0	0
Myxomatosis	0	0%	3	14%	0	2
Pfeiffer‘s glandular fever	1	1%	2	10%	0	0
Asian flu	1	1%	1	5%	0	0
Hepatitis D	1	1%	1	5%	0	0
Lymphoma	0	0%	2	10%	0	0
Gastritis	2	3%	1	5%	1	0
Avian pest	0	0%	3	14%	10	01
Zika/Microencephalitis	0	0%	3	14%	0	1
Malformations of the unborn child/embryo	0	0%	2	10%	0	0
Multiple Sclerosis	0	0%	2	10%	0	2
Penile cancer	0	0%	2	10%	0	0
Swine pest	1	1%	1	5%	0	0
Cytomegaly	0	0%	2	10%	0	1
Anal cancer	0	0%	2	10%	0	0
Amnesia	0	0%	1	5%	0	1
Cystitis	0	0%	1	5%	0	1
Burkitt‘s lymphoma	0	0%	1	5%	0	0
Diabetes Type I	0	0%	1	5%	0	0
Cat leukaemia	0	0%	1	5%	0	0
Clitoral tumor	0	0%	1	5%	0	0
Marburg fever	0	0%	1	5%	0	0
Morbus Hodgkin	0	0%	1	5%	0	0
Rhizomania	0	0%	1	5%	0	1
Slapped cheek syndrome	0	0%	1	5%	0	0
Vulval tumor	0	0%	1	5%	0	0
Vaginal tumor	0	0%	1	5%	0	0
Hepatitis E	0	0%	1	5%	0	0

). It was mainly books for grade 8 that referred to the most viral diseases (>15) and explained the viruses causing these diseases in detail.

3.4. Measures for Prevention of Infection and Ways of Transmission

A total of 64 books (66%; 47 lower and 17 upper secondary) presented at least one way to prevent becoming infected with a virus. All the measures found are listed in

Table 4. Measures of prevention against infection with viruses found in the analysed schoolbooks, sorted by frequency.

Measure of Prevention	Frequency
	Lower Secondary Books	Upper Secondary Books	Total
Vaccination	47	17	64
Condom	25	7	32
Keeping distance/avoid contact	16	2	18
Hygiene	12	3	15
Single-use gloves	8	1	9
Sterilization	6	2	8
Resuscitation cloth	3	0	3
Faithfulness/sexual abstinence	1	2	3
Antiretroviral therapies	0	3	3
Post-exposure prophylaxis	0	1	1
Genetically modified virus-resistant plants	1	0	1

. Similar measures were grouped under the same heading. For example, “hand-washing” and “intimate hygiene” were summarized as “hygiene”; burning infected dead animals and using only sterile needles for injection were summarized as “sterilization.” As seen in Table 4, vaccination was the measure most often highlighted. Viral diseases against which vaccination is available and that were mentioned in the analysed books are listed in

Table 5. Viral diseases against which vaccination is possible found in the analysed schoolbooks, sorted by frequency.

Disease against Which Vaccination is Available	Frequency
	Lower Secondary Books	Upper Secondary Books	Total
TBE	26	5	31
Hepatitis B	10	8	18
Measles	11	5	16
Rabies	12	4	16
Influenza	9	6	15
HPV	9	6	15
Poliomyelitis	12	3	15
Rubella	9	4	13
Mumps	8	4	12
Pox	4	3	7
Hepatitis A	2	2	4
Rabies (referring to foxes)	4	0	4
Chicken pox	3	1	4
Rotavirus	2	1	3
Hepatitis	2	0	2
Cat Leukaemia	0	1	1
Feline rhinitis	1	0	1
Swine flu	0	1	1
Distemper	1	0	1

.

A total of 66 books (53 lower and 13 upper secondary) informed readers about at least one way of contracting a viral disease.

Table 6. Routes of infection for viral diseases described in the analysed schoolbooks, sorted by frequency.

Route of Infection	Frequency
	Lower Secondary Books	Upper Secondary Books	Total
Animal bite	34	5	39
Sexual intercourse	23	9	32
Skin contact	20	7	27
Droplets	16	6	22
Blood	15	8	23
Body liquids in general	14	8	22
Food/drinking water	12	3	15
Inhaling	10	3	13
Transmission from mother to child (e.g., during birth)	7	6	13
Smear infection	7	1	8

shows the infection routes most often referred to. Alternative names of similar ways of transmission were grouped below the same heading, e.g., “via breathing air” and “via breathing” as “inhaling.” Very rarely, infections of plants were mentioned, e.g., rhizomania (via fungi), or via nematodes.

3.5. Replication of Viruses

The replication of viruses is described in 30 books (31%; 16 in lower and 14 in upper secondary), with eight lower and nine upper secondary books providing detailed descriptions.

3.6. Reference to Viruses in Contexts Other Than Viral Diseases

A total of 9 books for upper secondary school mentioned viruses in a context other than viral diseases, 1 for grade 9 and 11 each, and all others for grade 12. Such contexts were:

-

Viruses as part of the microbiome;

-

Scientific theories regarding the origin/genesis of viruses;

-

Gene therapy (somatic and germ line therapy);

-

Vectors in genetic engineering (cloning), genetic engineering in agriculture, and the creation of genetically modified bacteria;

-

Bacteriophages.

3.7. Content/Wording Mistakes

We found 18 mistakes in 15 books. A total of 14 mistakes were found in books for lower and four in books for upper secondary school. The mistakes and suggestions for correction are displayed in

Table 7. Mistakes found in the analysed schoolbooks and suggestions for correction.

Mistakes in Content and/or Wording	Suggestion for Correction/Comments
“Watch for possible signs of illness (mild flu, reddening of skin around the bite).” (grade 6)	A tick bite does not cause flu. However, flu-like symptoms can occur.
“Ticks can transmit two different pathogens: TBE viruses and Lyme disease bacteria.” (grade 6)	Ticks can also transmit further diseases.
“Don’t overestimate how dangerous ticks are, but don’t underestimate them either! In any case, proper behaviour after a tick bite helps avoid serious consequences.” (grade 6)	We believe that the danger of tick bites is left unclear. For example, quickly removing a tick after it has bitten does not necessarily help against TBE. Only vaccination as a precautionary measure helps here. In contrast, lyme disease can be treated with antibiotics—but has to be diagnosed first. Wearing long-legged pants would be a protective measure.
“Cases of meningitis transmitted by ticks occurred mainly in the east and south of Austria.” (grade 6)	Meningitis is widespread in most Austrian districts.
“Fever prevents new viruses from emerging.” (grade 8)	Viral replication is not necessarily prevented by fever. This depends very much on the specific virus. For example, viruses whose genetic material is integrated into host DNA (as with HIV) will not become attenuated once such gene integration has taken place.
“They attach to a cell and transfer their genetic information into it. In this way, they force the host cell to produce new viruses in its nucleus.” (grade 8)	By far not all viruses are replicated in the nucleus. Most RNA viruses are replicated in the cytoplasm. In any case, replication does not occur in the nucleus only.
“If the body is actually attacked by the corresponding viruses, it can react immediately.” [This quote is preceded by text referring to vaccination in general.] (grade 8)	First, there are also vaccines against other pathogens than viruses. Second, vaccination need not be successful for some vaccines.
“Since their size is only 0.015–0.44 μm, you can’t even see them in a light microscope, only in an electron microscope.” (grade 8)	Although correct for many viruses, much larger viruses exist.
Concerning HIV/AIDS: “The virus introduces its genetic material into the cell, while the protein envelope remains outside the cell. At this stage, it can remain dormant for years.” (grade 8)	During replication of the HI virus, the viral envelope fuses with the cell membrane, so it does not remain outside. Furthermore, dormancy is possible after the viral RNA has been reversely transcribed into DNA and subsequently inserted into the host cell DNA.
“Jaundice is an inflammation of the liver”. (grade 8)	In fact, jaundice is a symptom, not itself a disease.
“On 17 January 1789, the English wound surgeon Edward Jenner conducted an extremely questionable and risky human experiment. He vaccinated his own 18-month-old son against what was then a very dangerous and contagious disease: smallpox.” (grade 8)	The year is incorrect (1796). Additionally, Jenner experimented on the son of a milkmaid, not on his own child.
“During pneumonia, parts of the lung tissue are inflamed by bacteria or viruses. (...) Pneumonia can be cured by medication.” (grade 8)	Drug treatment, even with antivirals, is not certain to cure viral pneumonia. (Possibly, the treatment with antibiotics is implicitly meant here, but this could lead to the wrong and dangerous misconception that viruses can be killed with antibiotics.)
Concerning HIV/AIDS: “At this stage, relatively harmless infectious diseases (e.g., influenza) can be fatal to those who contract them.” (grade 8)	Influenza may be deadly for non-HIV infected people, too.
“Invaders foreign to the body, such as bacteria, viruses or fungi, are known in medical language as antigens.“ (grade 8)	In fact, the (surface) components are called antigens, not the entire virus/organism.
“Read the text carefully. There are 15 errors!” [Quote from a task in which mistakes are to be identified.] (grade 9)	Unfortunately, no solution is given. Thus, misconceptions possibly created by the text may persist.
“In addition, diseases such as viruses (e.g., HIV, HPV), bacteria (...) can be transmitted during sexual intercourse.” (grade 10)	HIV and bacteria are not diseases per se, but are causal agents of them.
Concerning HIV/AIDS: “...infection can be detected at an early stage (about three months after infection).” (grade 10)	An HIV infection can be detected by polymerase chain reaction (PCR) much earlier than 3 months.
“For this purpose, genes from other living organisms (e.g., from bacteria, fungi, viruses, ...) are introduced into the genome.” (grade 12)	Viruses are non-living particles, not organisms.

.

3.8. Incomplete Presentation of Virus-Related Information

According to our rating, 67 textbooks (69%) did not provide the information in such detail as seems necessary. Of these, 54 textbooks were for lower secondary and 13 textbooks for upper secondary school. In total, 82 text sections would have profited from more in-depth information. Very often, the concerned diseases (e.g., HIV, influenza, rabies, TBE) were named without any further explanation and often even without mentioning that the causal pathogen is a virus. Details about the structure and size of viruses as well as their differences to bacteria and/or other organisms were missing in several books. Replication was often presented and explained incompletely (e.g., one or several steps were missing). The latter was true even for some books for upper secondary school (examples for this and all other categories can be found in Supplementary Material S3).

3.9. Summary of Virus-Related Knowledge Presented in the Analysed Books

In conclusion, many details about viruses could be found in the books we analysed, but individual books often omitted much of the information that we deemed important, even though other books of the same grade provided it.

Table 8. Important virological aspects and percentage of analysed books dealing with them. Aspects printed in bold are believed to be particularly important by the authors to understand viruses and possibilities to protect oneself against viral infections.

Aspect	% Lower Secondary Books	% Upper Secondary Books
Text parts exclusively relating to viruses	67%	95%
References to viruses	49%	100%
Defining viruses as non-living	16%	57%
Structure of viruses	17%	67%
Size of viruses	24%	71%
Differences to bacteria	24%	52%
Inefficiency of antibiotics	12%	14%
Viral diseases	78%	95%
Detailed description of such diseases	61%	67%
Preventive measures	74%	76%
Vaccination	62%	81%
Active and passive immunization	24%	29%
Routes of infection	70%	62%
Replication	21%	67%
Detailed description of replication	11%	43%
Viruses referred to in context other than diseases	0%	43%
Free of mistakes	62%	81%
Completeness in presentation of addressed virus-related topics	29%	38%

lists key aspects we believe should be discussed in biology schoolbooks and it shows how many books referred to such aspects.

3.10. Visual Representations of Viruses

A total of 70 illustrations of individual viruses were found in 33 books (34%). Of these, 40 illustrations were included in 14 lower secondary books and 30 illustrations in 19 upper secondary books. Thus, 18% of books for lower and 90% of books for upper secondary grades showed at least one virus. All the illustrations were classified as correct, but five as incomplete. All electron microscope images were rated as correct and complete, but two images were not labelled and 26 incompletely labelled (e.g., surface structures were drawn but not labelled).

With respect to replication, we found that this process was illustrated in 19 textbooks (20%), with 26 different illustrations in total. Of these, 11 illustrations were found in 10 books for lower and 15 illustrations in 9 books for upper secondary school. Thus, 13% of books for lower and 43% books for upper secondary grades explain replication graphically. Of these, 4 illustrations were classified as incorrect and 11 as incomplete.

3.11. Further Virus-Related Illustrations

A total of 73 other types of virus-related illustrations were found in 30 textbooks (31%). A total of 29 of such illustrations were found in 17 books for secondary and 44 such illustrations in 13 books for upper secondary grades. Here, 2 illustrations were classified as incorrect and 14 as incomplete.

3.12. Pictures of Symptoms of Viral Diseases

We discovered 39 illustrations of disease symptoms in 21 textbooks (22%). A total of 29 of such pictures were found in 14 books for lower secondary and 10 in 7 books for upper secondary.

3.13. Tables and Diagrams Related to Virology

A total of 60 tables or diagrams were found in 29 books (30%). All of them were classified as correct. A total of 28 were found in 16 books for lower and 32 in 13 books for upper secondary school.

In summary, at least one illustration, graph, or table related to viruses was found in 45 of the textbooks analysed (46%), which was true for 25 lower secondary books (33%) and 20 upper secondary books (95%). Only one textbook for upper secondary school did not contain any graphic elements concerning viruses.

3.14. Scientific Terms

A total of 984 different scientific terms were noted: 472 terms in 65 books for lower secondary and 690 in all books for upper secondary school. The following 52 terms were mentioned most frequently and in at least 10 different textbooks (frequency in parentheses) (in German, many of these terms are compound nouns): disease-causing agent (46), vaccination (39), infection (37), immune system (33), to infect (32), host cell (32), symptom (31), antibody (28), bacteria (28), pathogen (28), protective vaccination (27), sexual intercourse (26), infectious disease (25), to vaccinate (22), vaccine (22), incubation period (22), condom (22), metabolism (22), antigen (20), immunodeficiency (20), antibiotics (19), inflammation (19), memory cell (17), mucous membrane (15), white blood cells (15), paralysis (14), parasite (14), droplet infection (14), active immunisation (13), lymph node (13), booster vaccination (12), genetic material (12), genetic information (12), immune (12), protection by vaccination (12), injection needle (12), semen (12), DNA (11), phagocyte (11), passive immunisation (11), seminal fluid (11), vaginal fluid (11), syndrome (11), tumour (11), viral (11), cell membrane (11), epidemic (10), genetic material (10), therapeutic vaccination (10), immunity (10), micro-organisms (10), and T-helper cell (10). Lower-grade books had 10–92 scientific terms, and 6–32.3 of such terms were used per virus-related page. The equivalent numbers for upper secondary school were 15–161 terms, and 7.1–75 such terms used per virus-related page.

3.15. Virus-Related Tasks and Relevance

A total of 346 virus-related tasks were found in 59 textbooks (61%). Of these, 207 were found in 39 lower secondary textbooks and 139 in 21 upper secondary textbooks. These tasks were assigned to different competence fields (

Table 9. Virus-related tasks sorted according to overall field of competency addressed.

Type of Task (Overall Field of Competency Addressed)	Number of Tasks
	Lower Secondary	Upper Secondary	Total
Elaboration of new knowledge/searching for information	61	52	113
Consolidation of knowledge	55	54	109
Evaluation of information/transfer to other/related fields	77	40	117
Gaining insight through experimentation	21	20	41

). Since some tasks included sub-tasks relevant for other fields of competency, the total number of assigned tasks in Table 9 is higher than the number of tasks. A total of 25 books contained at least five different tasks in conjunction with virology.

3.16. Demonstration of Relevance for Daily Life

In 61 of the textbooks analysed (63%), attempts were made to demonstrate the relevance of the topic for students, e.g., directly addressing students, tasks with apparent connections to students’ life, or applicable information. Such references to daily life were noted for 48 (63%) lower and 13 (62%) upper secondary books. The book rated best in this category contained the following references to students’ life:

-

Therapy—more than 30 years after the discovery of HIV, there is still no vaccine against AIDS;

-

A task to determine one’s own vaccination record and infectious diseases experienced as a child;

-

Evaluating various situations for the risk of contracting HIV;

-

Explaining that one’s HIV status can be tested in Austria for free;

-

A discussion of vaccination fatigue;

-

A task to analyse the Austrian vaccination scheme;

-

A task about the danger posed by mosquitoes/gnats;

-

A task showing that vaccination against poliomyelitis is still relevant.

4. Discussion

4.1. Content

Our analyses show that virology as such is present in the majority of books, even in those for lower grades and not only in books written for grades in which the Austrian curriculum explicitly recommends teaching about health issues and, especially, HIV/AIDS. However, except for books for grade 8 and a few individual books for other grades, the extent to which virus-related content is presented seems rather small. Even within the same grade books differ widely in the space they attribute to virology. However, a very high number of various viruses and viral diseases is named across all books, with those of special relevance for Austria occurring most frequently. Furthermore, several schoolbooks take some effort to explain infection routes and measures to prevent transmission. This is no surprise, as it is required by authorities worldwide to discuss such matters at school within the thematic field of “health and diseases.” Thus, many studies have shown that knowledge about hygiene measures (e.g., handwashing, the use of condoms, and sneezing in one’s arm pit) is very much existent in a large part of the population [12,43,44,45]. On the other hand, this is less true for the trust in and application of vaccination [1,46,47,48,49,50,51]. Thus, vaccination as an important means to prevent the spread of certain diseases such as COVID-19 or measles apparently needs to be discussed in more detail in school (books).

In Austrian schoolbooks, vaccination as a preventative measure is named very often. However, the way various vaccines work, the levels needed for herd immunity, the vaccine constituents, and the risk of side-effects and vaccination damage is rarely dealt with, which is mirrored in several misconceptions found amongst Austrian students and adults [1]. Although cellular and molecular mechanisms for specific vaccines could be too challenging for many—particularly younger—students, the basic functioning of vaccines can and should be explained to all (e.g., making the body sensitive to potentially invading pathogens by preparing its immuno-defence).

Furthermore, only very few books explicitly state that viruses are non-living and cannot be destroyed by antibiotics, and in too many of the analysed books, a clear-cut distinction between bacteria and viruses is missing. This is a severe gap. As we have pointed out earlier, the misconception that viruses can be destroyed by antibiotics is widespread. However, viruses do not have metabolic pathways with which these substances could interfere with. For both biological and medical reasons, students must understand that viruses are very distinct from living beings. Such an understanding—based on a comparison of the structures of bacteria and viruses [1,2,9]—may help to diminish the pressure on physicians exerted by many patients to have antibiotics prescribed. The existence of such pressure has been documented [52,53,54]. Moreover, we urgently need to reduce the misuse of antibiotics. Otherwise, one of the next pandemics may be caused by antibiotic-resistant bacteria, since antibiotics, among the most powerful weapons of modern medicine, are becoming increasingly useless against several bacterial strains [54,55].

Finally, it must be acknowledged that we discovered only very few content-related mistakes. Those we found were mostly either incorrect generalizations or a lack of detail, both of which may cause misconceptions (e.g., that viruses are always replicated in the host cell’s nucleus) and should be corrected. The low number of mistakes does not come unexpectedly, since all Austrian textbooks are reviewed by experts before being approved for use.

We concede that schoolbooks have to cover a wide variety of topics, with virology being just one of several within the field ‘health and diseases’. Yet the COVID-19 pandemic has repeatedly shown that too many people do not believe in the existence of some viruses; do not know that they are not living organisms and cannot, thus, be killed by antibiotics; do not believe that vaccination against several dangerous viral diseases is highly efficient; and overestimate the risk and severity of vaccination damage [56,57,58,59,60,61]. Therefore, we believe that virology needs a more prominent place in schoolbooks. For even if teachers may not be able to have all pages worked through in class, some students (and/or their parents) may use these books as a source for information [24,25,26,27,28,29], if the topic is presented comprehensively and attractively. To give virology the space it deserves and to make the virus-related information delivered less dependent on individual authors, we recommend that virology gains more attention in curricula for secondary schools. This applies not only to Austria, but to other countries as well, even though there might be some variation within states; for example, little reference is made to virology in the lower secondary curriculum for biology in Germany’s biggest state, North Rhine-Westphalia [62], while virus-related topics are referred to relatively often in the curriculum for grade 8 in the German state of Bavaria [63]. Regarding the U.S., it has been found that the situation very much depends on the individual school. Thus, a school focusing on sciences may offer very detailed information concerning virology and even practical work, while students at other schools may learn virtually nothing about viruses [64]. However, the essential health education an individual student receives should not depend on a school’s location or type.

4.2. Illustrations

Many of the analysed books show pictures or sketches of viruses. However, in several books, such a graphical representation of viruses is missing, even when virology is dealt with in more detail in these books. While almost all upper secondary books display at least one illustration showing a virus, this was true for less than a fifth of the analysed books for lower secondary schools. Since about 56% of middle school students leave school after grade 8 or 9 (the latter attending mostly polytechnic schools without much biology in grade 9) [37], many Austrian students will never be confronted with the potential appearance of a virus. This may explain why so many students and adults had severe problems identifying viruses when given the choice between sketches showing an enveloped virus, a phage, a plant cell, an animal cell, or a bacterium [1]. Yet having a visual impression of a virus may be important for realizing that viruses are something very much distinct from living organisms in general and bacteria in particular (see below). As Jones et al. (2003) observed, “students’ preconceptions of viruses resembled images they had seen previously in textbooks and on television” (p. 318, [65]). Visual impressions may thus influence the understanding of viruses greatly. This also relates to size, e.g., in relation to a human cell. Here, the analysis of large viruses in pre-stained tissues with light microscopes may contribute to visually understanding viruses [66]. Since there is a plethora of illustrations and even videos available on the internet, both teachers and schoolbook authors may find enough material to demonstrate the appearance of viruses. However, educators need to take care in checking such material first, so that it does not fuel or create misconceptions (e.g., that viruses or bacteria are evil, or that viruses are living beings because they have a mouth and teeth attacking human cells as found in several graphics and animations).

On the other hand, several authors used well-designed sequential graphics to illustrate complex topics such as viral replication. The importance of well-designed illustrations to foster students’ understanding of specific science content has long been known. In particular, labelled illustrations and sequences of illustrations (in the case of processes) seem to aid learning and knowledge transfer [67]. However, even though several of the analysed schoolbooks fulfil this requirement, there is room for improvement. For example, only 14 of the 21 upper secondary books dealt with replication, and less than half explained this with a graphical aid.

With respect to symptoms of viral diseases, some children may find such pictures repulsive. On the other hand, this may be the case for many non-viral diseases shown in schoolbooks, too. We believe that it is the task of the teacher to explain what is depicted and to indicate how such a disease may be prevented or treated. This may even create interest in medical virology. Diseases are part of our life and should not be regarded as something to be ignored, which also holds true for those suffering from such a disease to avoid prejudices and reduce stigma.

4.3. Tasks/Relevance for Daily Life

Viruses are invisible to the naked eye, which makes them a difficult subject for experimentation at school. Cunning ideas such as nano-scale tasks tested in Jones et al. (2013) [65] will be difficult to perform for most classes. Nevertheless, various hygiene measures can easily be tested and discussed at school. For example, students may press their hand on petri dishes filled with media to enable the growth of bacteria and fungi before and after handwashing, even with the application of a yeast suspension (as a model) on their hands to test the effect of handwashing in between shaking hands with each other. Further relevant tasks could be to search for information about vaccination levels needed for a population to reach herd immunity, as such knowledge is apparently scarce [1]; to examine the spread of certain viruses and its relation to vaccination status (e.g., using the Johns Hopkins University’s COVID-19 dashboard: https://coronavirus.jhu.edu/map.html (accessed on 24 July 2022)); or to create posters for a school exhibition to show the differences between viruses and bacteria and to discuss the implications (e.g., in terms of antibiotics use), possibly including interviews with physicians. Analysing pre-stained viruses in human cells as in [66] could be an interesting task to understand both their size and the fact that viruses are intracellular pathogens. Furthermore, there are several interesting internet resources or games for understanding the differences between bacteria and viruses in terms of antibiotic efficiency [68] or the spread and the containment of a pandemic [69]. A virus’ structure may also be better understood by creating 2D- or even 3D-models—some examples of this can be found in [70].

Several schoolbooks point out the relevance of virological knowledge, e.g., by making explicit that certain diseases may pose a danger to the readers, by analysing vaccination schemes, or by discussing various possible ways of contracting a virus. Deci and Ryan (2008) demonstrate, how important it is to realize the individual relevance of a specific topic for the creation of interest in that topic [71]. Many schoolbooks have apparently performed well in this respect. It remains to be seen in further studies whether students recognise such relevance for themselves. Our own studies have shown that virology itself is a highly interesting topic for many [1,10].

4.4. Language

The number of scientific terms is rather high in many text sections dealing with virology but differs widely between books even within one grade. However, language plays an important role for comprehensibility of schoolbooks; that is to say, it is important that scientific language is used in a way such that students can understand it without too much effort. Some studies on German natural science schoolbooks have found that the number of scientific terms possibly new to students is extremely high even in books for lower secondary grade science [37]. For such books, Merzyn (1994) noted between 1500 and 2500 different scientific terms, with every sixth word being a scientific term, every twenty-fifth word being a new term, and approximately 50% of all terms being used only once in a specific textbook [37]. This may result in cognitive overload. Consequently, schoolbook authors should carefully choose which terms they use and whether these terms may require an explanation either in a glossary or directly in the text (as in some of the analysed books in our study).

Finally, the coding matrix and the coding guide we have developed and used for our virus-related schoolbook analysis have proven very useful and reliable. Thus, we can recommend these tools for analyses of textbooks with respect to virology.

4.5. Conclusions

In summary, virology is dealt with quite extensively in some textbooks but rather superficially in other textbooks we analysed. Since we found very few mistakes (and those found were mostly related to over-generalization and a lack of detail), the quality assurance process in the Austrian schoolbook commission system seems to work efficiently. Nevertheless, some issues need amendment. In particular, graphic representations of viruses and their size, the differences between viruses and bacteria, the highlighting of the inefficiency of antibiotics against viruses, more detailed information about vaccines, and a discussion of the probability of side-effects and vaccination damage, as well as more stimulating/experimental tasks, might help to tackle some of the most pressing problems in public health, namely, (i) the rise in antibiotic-resistant bacterial strains due to the misuse of medication and (ii) vaccination hesitancy or even scepticism. Schoolbooks have a decisive role in educating future patients. Thus, they should address such problems carefully to help students and their parents to make well-grounded, information-based decisions in health-related situations (e.g., whether to take antibiotics, whether to become vaccinated, etc.). In this respect, biology schoolbooks as part of the setting “school” in the DARAHM model may play an important role in health education and the decision-making process of young people.

5. Limitations

Our book analyses are based on the knowledge, experience, and interest of biologists/prospective biology teachers. Naturally, students—for whom these books have been written—may rate various aspects rather differently. For example, whether a particular illustration is comprehensible and well-made may be perceived differently by experts and novices. Furthermore, students may define other and probably more words used in the text as scientific terms. Thus, a follow-up study comparing the rating of schoolbooks by experts and novices would be highly interesting.