Bibliometric analysis of SARS, MERS, and Covid-19 studies from India with focus on sustainable development

India is ranked 5th in world in terms of Covid-19 publications accounting for 6.7% of the total. About 60% of the Covid-19 publications in the year 2020 are from United States, China, UK, Italy, and India. We present a bibliometrics analysis of the publication trends and citation structure along with identification of major research clusters. By performing network analysis of authors, citations, institutions, keywords, and countries, we explore semantic associations by applying visualization techniques. Our study shows lead taken by United States, China, UK, Italy, India in Covid-19 research may be attributed to the high prevalence of Covid-19 cases in those countries witnessing the first outbreak and also due to access to Covid-19 data, access to labs for experimental trials, immediate funding, and overall support from the govt. agencies. Large number of publications and citations from India are due to co-authored publications with countries like United States, UK, China, and Saudi Arabia. Findings show health sciences with highest the number of publications and citations, while physical sciences and social sciences and humanities counts were low. A large proportion of publications fall into the open access category. With India as focus, by comparing three major pandemics SARS, MERS, Covid-19 from bibliometrics perspective, we observe much broader involvement of authors from multiple countries for Covid-19 studies as compared to SARS and MERS. Finally, by applying bibliometric indicators, we see an increasing number of sustainable development-related studies from the Covid-19 domain, particularly concerning the topic of good health and well-being. This study allows for a deeper understanding on how the scholarly community from a populous country like India pursued research in the midst of a major pandemic which resulted in closure of scientific institutions.


Introduction
The present Covid-19 pandemic has affected every socioeconomic sector. Globally, everything from manufacturing to entertainment has been affected. Academia is no exception. In fact, most universities globally have suspended on campus activities and have moved online [1]. While teaching practices can to some extent be mitigated by digital interventions and online teaching, research is more complex and often requires campus collaboration and laboratory facilities [2]. While safety norms may require research to be suspended, research is also an essential first step in understanding and fighting this pandemic. Given that it is a novel virus, research regarding its characteristics is integral to developing mechanisms for fighting it. Similarly, methods of detection, isolation, protection, etc. also need to be developed at a fundamental level. In addition, given the scale of the pandemic, research on its effects on other aspects ranging from the global supply chain to mental health need to be understood and any adverse effects mitigated [3] [4]. In light of all these needs, the researchers across the world have continued their work even under these challenging conditions, generating an impressive volume of research during this time [5]. In fact, during the early stages of the Covid-19 pandemic, researchers produced a significant number of publications, and the number started growing exponentially, doubling every two weeks by April 2020 [6]. open access platform for the same [9]. The European Union adopted a similar policy by March 2020 [10]. In order to accelerate the speed of publication, a number of preprint services were set up as well. Though they lack the stringency of a detailed peer review process, such approaches have aided in rapid information sharing [11] [12]. When compared to other similar infections such as MERS and SARS, Covid-19 has resulted in a mass mobilization of scientific effort, with over 12,000 papers being generated in under five months. The volume of work available at preset on this virus alone is greater than the number of publications generated on all coronaviruses over the last two decades [13]. Clearly, the research community has pulled its weight when it comes to achieving Sweden did not impose any major restrictions.
Most of Europe had less stringent policies than India as well [16]. All these approaches had varying degrees of success. Even within India, the success of the response varied from state to state, some faring better than others [17]. However, the overall death rates and per-capita deaths in India have been lower than those of most countries. As of May We have structured the paper as follows: Section 2 discusses the study methodology using bibliometrics including the search strategy. Section 3 presents the results in terms of publications, citations, institutions, and countries. Section 4 provides the network analysis with visual representation of bibliographic data while Covid-19 studies connected to Sustainable development are presented in Section 5. And finally section 6 is about conclusions of the study with future directions.

Study methodology using bibliometrics
Bibliometrics is a set of methods to measure scholarly impact from research publications. Bibliometrics tools have been used in a variety of analyses [19][20], including those of authors, journal sources, and citation trends [21] or country [22]. Many journals have published bibliometric studies on pandemics such as SARS, MERS, and more recently on Covid-19 [13] [23][24][25][26].

Selection of bibliometric software mapping tools and data sources
The VOSviewer [27] software was used to analyze the co-occurrence network for keywords, co-authorship network [28], citations [29] and bibliographic coupling [30]. The h-index [31] which is widely used in bibliometric studies [32] was also analyzed.
In our study we also considered data sources, https://www. SARS: ( TITLE-ABS-KEY ( ( ( "Severe acute respiratory syndrome" OR "SARS") AND ( coronavirus*)) OR ( "SARS virus" OR "SARS disease" OR "Severe acute respiratory syndrome disease" OR "Severe acute respiratory syndrome virus" OR "SARS-Cov")) AND NOT TITLE-ABS-KEY ( ( "covid" OR "nCov" OR "Covid-19" OR "covid19" OR "SARS-Cov-2" OR "Severe acute respiratory syndrome-2" OR "MERS" OR "middle east respiratory syndrome"))) AND PUBYEAR > 2001.    to be on a scale that is unprecedented in the history of coronavirus research, and probably perhaps in the history of science. Covid-19 may be attributed to the time required for peer review process as softer letters and reviews do not have to pass that hurdle.  Memorial has a citation per publication score of 6.2. However, among private sector institutes, the highest citation per publication is 3.7 for CMC Vellore. Clearly, public medical institutes have exceeded their private counterparts in academic excellence in this area. This is partly due to government funding and ease of access enjoyed by these institutes with regards to viral samples and data for clinical studies. studies.

Co-authorship network and publications
In order to study the collaboration networks of authors, we used co-authorship network analysis which is a widely accepted practice in bibliometric studies [36].
In a network graph, each author is represented by a bubble and the bubble size is proportional to the number of publications attributed to the author. Two authors who have collaborated on any paper are linked by a line, with each line representing collaboration on a single paper. Colors indicate clusters of authors that are relatively strongly connected by co-authorship links and authors with a high degree of collaboration are located close to each other.
We investigated the co-authorship network in India, with authors having at least 15 Covid-19 related publications. This resulted in 7 major collaboration clusters with a total of 132 authors, as can be observed in Fig. 1.

Fig. 1 Co-authorship network and publications in India
The important clusters in the co-authorship network of authors shown in the following colors: red corresponds to authors "kumar a", "kumar s", "sharma p"; green color to author "gupta n"; yellow to author "das s" and finally blue to "dharma k". As indicated by the size of the bubble, those are leading authors who produced highest number of papers in collaboration with others.

Co-citation network of authors
Similarly, we investigated the co-citation network of Indian authors with at least 5 citations. Note that co-citations indicate formats that contain ideas, experiments, or methods that have received peer recognition, as evidenced by their co-occurrence of citations [37].
This network analysis resulted in 6 clusters, where 124 out of the 12,417 authors had at least 5 citations, as shown in Fig. 2. Each author is represented by a node whose size is proportional to the number of citations. The important clusters of citations appear in the following colors: red corresponds to author "dharma k"; green to author "chakrabarthi s"; yellow to author "gupta n" and finally color to "sharma s". As indicated by the size of the bubble, those are leading authors with the highest number of citations.

Co-occurrence network of keywords
When searching for scientific publications, a key word search is usually the easiest way to access relevant information. Therefore, appropriate key words that provide a reasonable description of the work allows the study to reach a wider audience. To carry out a keyword-based analysis, keywords described by at least 5 publications were chosen and a co-occurrence network constructed. The unit of analysis has also been set to all keywords (this includes both author and index keywords) and the method of counting was set to full counting. These results are shown in Fig. 3, where it can be seen that works published by Indian authors have employed a wide range of key words, ranging from those related to virology and epidemiology to those associated with mental health, air pollution, and lockdown. This indicates that the work generated in India spans multiple disciplines and covers a diverse gamut of topics related to the pandemic.
With respect to each of the three epidemics, distinct clusters of keywords were identifiable but there were commonalities among them. All three epidemics had a cluster with terms such as pandemic, infection control, viral, epidemic, virus transmission associated with general public health and disease outbreak. Another cluster had terms that are generally associated with virology studies like virus protein, virus entry, chemistry, amino acid sequence, virus genome, protein binding, etc.

Bibliographic couplings among countries
Bibliographic couplings are described by [38] which proposes that two papers that refer to a third paper are highly related, so they should be grouped into a cluster solution.    ing a data crisis [47]. It is also important to note the significant number of studies documenting connections between Covid-19 and SDGs 8 (on economic growth) and 4 (on quality education), which reflect the negative impact of the Covid-19 restrictions on two very important areas of our societies. Perhaps two areas that have not received sufficient attention according to Table 9 are the negative effects on SDGs 1 (on no poverty) and 5 (on gender equality), which have undoubtedly experienced quite negative effects from Covid-19.

Conclusions
In the present study the authors performed a bibliometric analysis on Covid-19 publications in India and at multiple places compared with world wide data. United States is the country with the highest number of Covid-19 publications in the year 2020.
This might reflect the fact that journal databases and referencing system usually refer to US standards. Many journals, with a wide range of impact factors, exhibit publications by Indian authors. The publications are the result of collaboration both within India and in the international scene. As also reported [48], who studied bibliometric features on the Covid-19 worldwide, our results indicate that the studies on Covid-19 are published by institutions worldwide. There are many publications in India, with a rapid increasing rate of publication after disease emerged in the country, in a pattern similar to that reported by [49]. This study also shows that there are many publications from both governmental and non-governmental institutes. A worldwide collaboration network can be clearly identified, and this agrees with the report by [50].
Collaboration in excellent way to increase visibility of the work and generalization of the knowledge. During the early stage of disease emergence, studies in the form of short report or viewpoints were common and become publications with high numbers of citations [51]. Such collaboration, and an active data-sharing policy, are essential aspects to fight this pandemic and other future crises [ Funding: This research received no external funding.

Conflicts of Interest:
The authors declare no conflict of interest.