Search Results (832)

Background: In Gulf nations such as Saudi Arabia, where COVID-19 vaccination is optional, parental decision-making regarding vaccinating children is critical. Understanding the psychological factors that drive these decisions can shape future vaccination strategies. Methods: Between November 2021 and January 2022, a cross-sectional, web-based validated survey was conducted using chain-referral (snowball) sampling across multiple social media platforms. A total of 2176 parents residing in Saudi Arabia with children aged 5–18 years participated. The 5C psychological antecedents (confidence, complacency, constraints, calculation, and collective responsibility) were assessed. Multinomial logistic regression was employed to determine factors influencing parental decision-making across three child age groups: 5–11 years only, 12–18 years only, and both age ranges (5–18 years). Results: Overall, 77.9% of parents agreed to receive all scheduled doses of the COVID-19 vaccine themselves, while 58.6% agreed to vaccinate children aged 12 years or older, and only 41.9% agreed to vaccinate children younger than 12 years. Fathers were significantly more likely to accept vaccination [Odds ratio (OR) = 17.48, p = 0.01] compared to mothers, who showed higher reluctance (OR = 15.08, p = 0.01). Having a child aged 5–11 years increased reluctance threefold (OR = 3.16, p = 0.01). Parents who believed that returning to school was safe showed increased vaccine acceptance (OR = 4.32, p = 0.01). Confidence and collective responsibility were the strongest positive predictors of vaccine acceptance, particularly for younger children, with OR estimates of 1.23–1.53 for confidence and 1.33–2.13 for collective responsibility. Conversely, extensive information seeking (calculation) was associated with lower acceptance (OR = 0.09, p = 0.03). A history of COVID-19 hospitalization among family or friends was significantly associated with increased parental reluctance (p = 0.03). Conclusions: This study identifies key psychological and demographic factors influencing parental decisions regarding COVID-19 vaccination for children. Building parental confidence and fostering collective responsibility are essential for increasing vaccination rates, particularly among parents of younger children aged 5–11 years. Healthcare authorities should address vaccine safety concerns, provide clear and accurate information, and tailor strategies to parents who remain hesitant. Full article

Background and Objectives: The pandemic caused by the SARS-CoV-2 infection has been named coronavirus disease 2019 (COVID-19) by the World Health Organization (WHO). Cancer patients may have been more adversely affected during the COVID-19 Pandemic due to their receipt of immunosuppressive treatments, higher burden of comorbidities, and greater nutritional vulnerability compared to the general population. The aim of our study is to identify potential measures by detecting changes in the nutritional statuses of patients with an oncological diagnosis who presented to our hospital during the COVID-19 pandemic, using the globally accepted NRS-2002 questionnaire. Materials and Method: Our study included 324 patients diagnosed with malignancy who applied to the outpatient clinic of Gaziantep University, Şahinbey Training and Research Hospital, Gaziantep/Türkiye, between December 2021 and January 2022 or were hospitalized in the service. Patients included in the study were evaluated in terms of clinical–demographic information and COVID-19-related characteristics using a sociodemographic data form we developed, and then the NRS-2002 questionnaire was administered. Results: Our study included 324 patients. Overall, 49.07% (159 patients) of the patients were male, and 50.93% (165 patients) were female. A total of 20.37% of our patients (66 patients) had COVID-19 disease. While those living with their families constituted 96.91% of the patients, at least one of the family members of 36.42% of the patients had COVID-19 disease. While 76.23% (247 patients) of the patients were vaccinated, 23.77% (77 patients) were not vaccinated. When NRS analyses were examined according to the type of malignancy, a statistically significant difference was found between NRS analyses according to the type of diagnosis. When NRS analyses were examined according to the stages of the diseases, it was determined that stage 4 patients were in the risk group in terms of nutrition. When NRS analyses according to age were examined, it was determined that patients over the age of 65 were in the risk group in terms of nutrition. When NRS analyses by gender were examined, it was found that male patients were in the risk group in terms of nutrition. When the NRS analyses were examined according to whether or not radiotherapy was administered, it was determined that the patients who received radiotherapy were in the risk group in terms of nutrition. Contrary to the literature, no statistically significant difference was found according to whether or not chemotherapy was administered. Conclusions: According to NRS analysis, no statistically significant differences were found in terms of nutritional status according to COVID-19 transmission and vaccination status. When NRS analyses were examined according to the delay of treatment during the pandemic period, it was found that patients who postponed treatment were in the risk group in terms of nutrition, while patients who did not postpone treatment were mostly in the follow-up group. In multivariable analyses, however, no independent relationship was identified between this parameter and NRS-2002 risk. Full article

Background/Objectives: The COVID-19 pandemic was a major challenge for healthcare systems and social life worldwide. During the pandemic, studies focused on examining structural changes in patient care and establishing new guidelines to manage COVID-19, but very few of them addressed patients’ perceptions and concerns regarding changes in cancer treatment during the pandemic. This study aimed to assess the changes in their therapy situation during three waves of the pandemic and the impact on their social life. Methods: This exploratory cross-sectional multicenter survey was conducted among patients with gynecological malignancies and breast cancer at gynecological oncology centers in Germany between October 2020 and February 2022. An anonymous paper-based 50-item questionnaire, available in German, assessed medical care, treatment modifications, mental health, and socioeconomic burden during the COVID-19 pandemic. Data were analyzed descriptively. Two subgroup analyses were conducted, comparing age groups ≤70 and >70 years, as well as patients with and without a migrant background. Results: Overall, 778 patients met the inclusion criteria of the survey (median age: 59; range: 24–93). In the majority of the patients (77.1%), the treatment schedules remained unchanged during COVID-19 pandemic. Treatment appointments were modified in a small number of patients (9.0%). Changes in therapy schedules were slightly more common among the second- and third-generation migrants and among patients ≤70 years. Despite the uncertainty of the COVID-19 pandemic, most patients (83.4%) kept their trust in the healthcare system. Acceptance of preventive measures was high, and 85.9% were willing to be vaccinated against COVID-19. Psychological symptoms such as worries and fear were reported by more than half of the participants during the last 2 weeks previous to the survey and more common among patients ≤70 years. Only 8.6% were more afraid of a COVID-19 infection than their cancer disease. Conclusions: Despite major challenges in cancer care due to the COVID-19 pandemic, access to cancer treatment and adequate management at gynecological oncology centers in Germany remained stable. The increased psychological burden in crises requires new infrastructure and should be addressed to improve patient care in future crises. The acceptance of taking preventive measures against COVID-19 was high among cancer patients. Full article

Background: Vaccine hesitancy is a global challenge affecting workplaces and academic institutions. Despite efforts, low vaccination rates persist in South Africa, increasing the risks associated with pathogen exposure. This study assessed the knowledge, attitudes, and perceptions (KAPs) of healthcare workers (HCWs) and students at a Nursing College regarding voluntary and mandatory COVID-19 vaccination. Methods: A quantitative cross-sectional study was conducted using a structured, self-administered electronic questionnaire. All eligible nursing students and staff at the participating Nursing College were invited to participate. Of the 504 eligible individuals, 372 completed the questionnaire, corresponding to a response rate of 73.8%. Data were analyzed using IBM SPSS Statistics version 30.0. Logistic regression and Mann–Whitney U tests were used to assess associations and differences between groups, with statistical significance set at p < 0.05. Results: Most respondents were female (302, 81.0%) and single (252, 67.9%). The age group 26 to 40 was most prominent (144, 38.8%). Only 42.2% of respondents (n = 157) were fully immunized with no boosters. Student nurses dominated (344, 92.5%), with 226 (60.9%) having no COVID-19 infections and 198 (72.0%) voluntarily receiving the vaccine. Occupation (p = 0.030) and age group (p = 0.027) were independently associated with reporting voluntary COVID-19 vaccination. Age was also associated with respondents’ attitudes and perceptions of the COVID-19 vaccine (p < 0.001) as well as their understanding of the vaccine (p = 0.002). Conclusions: Occupation and age group were independently associated with the reported basis on which COVID-19 vaccination was received (voluntary versus mandatory). Targeted communication and educational strategies addressing these factors may improve vaccine acceptance and preparedness for future outbreaks. Full article

Background: Local vaccine manufacturing is being pursued across Africa to improve pandemic preparedness and reduce reliance on imports. In Nigeria, where COVID-19 vaccines were largely imported, willingness to accept locally produced vaccines is important for sustainable domestic production. The objective of this study was to estimate willingness to accept a locally manufactured COVID-19 vaccine among adults in Lagos, Nigeria, and to identify demographic predictors. Methods: We conducted a cross-sectional survey of adults in Lagos State from 7 September to 16 September 2024, using a questionnaire administered in four open-air markets. The primary outcome was willingness to accept a COVID-19 vaccine manufactured in Nigeria (yes/no). We summarized respondent characteristics, tested bivariate associations using chi-square tests, and estimated adjusted odds ratios (AORs) using multivariable logistic regression. Model calibration and discrimination were assessed using Hosmer–Lemeshow testing and the area under the ROC curve (AUC). Results: Of 388 consenting respondents, 335 provided complete data (86.3%). Respondents were predominantly female (60.6%); the largest age groups were 25–34 (30.2%) and 35–44 (28.4%) years. Overall, 75.8% reported willingness to accept a Nigerian-made COVID-19 vaccine. Willingness differed by age group (p = 0.0028; trend p = 0.0002) and religion (p = 0.0403). In adjusted models, respondents aged 45–54 years (aOR 6.54; 95% CI: 1.73–24.79) and 55–64 years (aOR 4.97; 95% CI: 1.05–23.55) had higher odds of acceptance than those aged 18–24 years. Christian affiliation was associated with lower odds than Muslim affiliation (aOR 0.41; 95% CI: 0.20–0.83). Discrimination was acceptable (AUC 0.75; 95% CI: 0.69–0.80). Conclusions: Most respondents were willing to accept a Nigerian-made COVID-19 vaccine, suggesting demand-side readiness. Confidence-building strategies tailored to younger adults and implemented with faith-based and community institutions may support uptake of locally produced vaccines. Full article

Cancer survivors face an elevated risk of severe COVID-19 outcomes and were prioritized for vaccination, yet reported rates of vaccination refusal in this population vary widely. The objective of this scoping review was to map the available evidence on COVID-19 vaccination refusal among adult cancer survivors in the United States, to characterize the reported barriers and enablers, and to examine how differences in measurement account for variation in the reported estimates. PubMed, EBSCOhost, CINAHL, medRxiv, and Google Scholar were searched for studies published between 1 December 2020 and 30 April 2026 reporting primary data on COVID-19 vaccination refusal among U.S. adults with a current or previous cancer diagnosis. Findings were charted and summarized descriptively. Six sources comprising 3344 participants met the eligibility criteria. Reported refusal ranged from 7.3% to 39.0%, a more than fivefold difference, with a median of 14.7%. This variation corresponded closely to what each source measured: declination of an offered vaccine, likelihood of acceptance on a Likert scale, hesitancy assessed before vaccines were widely available, or observed non-receipt of any dose. Barriers included concerns about vaccine safety, efficacy, and interaction with cancer treatment, mistrust of science and government, and low perceived need; clinician recommendation was the most consistent enabler. Estimates of vaccination refusal in this population are not directly comparable and should be interpreted alongside the construct measured. Full article

Background/Objectives: Vaccination remains an important means of protection against influenza and COVID-19. Administering influenza and COVID-19 vaccines as a combined formulation may be advantageous. Methods: This phase 3, randomized study evaluated an investigational combination nucleoside-modified messenger RNA (modRNA) vaccine formulated with monovalent XBB.1.5-adapted BNT162b2 vaccine (BNT162b2) and an investigational influenza modRNA vaccine (hereafter investigational combination modRNA vaccine); we report safety, tolerability, and immunogenicity of the investigational combination modRNA vaccine in healthy 18- to 64-year-olds in two cohorts (2 and 3). Results: In Cohort 2, 3127 participants received the investigational combination modRNA vaccine and 1563 received the concomitant licensed quadrivalent influenza vaccine (QIV) with BNT162b2. In Cohort 3, 1189 participants received the investigational combination modRNA vaccine, 605 received QIV, 607 received the investigational influenza modRNA vaccine, and 1191 received BNT162b2. Prespecified noninferiority criteria of the geometric mean ratio of strain-specific hemagglutination inhibition (HAI) or SARS-CoV-2 Omicron XBB.1.5 neutralizing titers or differences in percentages of participants achieving HAI sero-conversion or Omicron XBB.1.5 seroresponse for investigational combination modRNA vaccine to concomitant QIV and BNT162b2 (or to QIV and BNT162b2 each administered alone in Cohort 3) were met for influenza A and SARS-CoV-2 Omicron XBB.1.5 strains but not for the influenza B strain. The investigational combination modRNA vaccine was well tolerated with an acceptable safety profile. Conclusions: The single-dose investigational combination influenza plus COVID-19 modRNA vaccine elicited robust immune responses against influenza A and SARS-CoV-2 with acceptable safety. Further work is required to optimize influenza B responses. The modRNA platform offers promise and potential advantages for vaccine development. ClinicalTrials.gov Identifier: NCT06178991 (approval date: 20 December 2023). Full article

Messenger RNA (mRNA) entered clinical medicine through vaccines, where the innate immune reactivity that complicates protein therapeutics acts as a built-in adjuvant. The success of the coronavirus disease 2019 (COVID-19) mRNA vaccines inspired an expansive vision of an mRNA 2.0 era extending the modality to rare and common diseases, with delivery framed as the principal challenge. This review accepts much of that vision but argues it rests on an unstated assumption: that all protein therapeutics form a single pharmacological class. They do not. We propose a taxonomy, the Dose–Response Architecture Classification, separating two classes. Exposure-controlled therapeutics require a specific quantity of active protein on a defined regimen, as outcomes depend on reproducible exposure; examples include insulin, erythropoietin, growth hormone, coagulation factors, and narrow-therapeutic-index biologics. Threshold-response therapeutics depend on surpassing a functional threshold rather than maintaining a precise concentration; these include vaccines, many enzyme-replacement therapies, genome editing, receptor-saturating antibodies, and immune-cell reprogramming. Because an mRNA drug is dosed as an instruction, and a single message is translated into a variable number of proteins through a multiplicative, stochastic intracellular chain, the dose-to-effect relationship is inherently variable. Our central, deliberately falsifiable proposition is that mRNA is suitable for threshold-response therapeutics but unsuitable for exposure-controlled therapeutics unless a construct or delivery system demonstrates validated post-delivery output control within predefined pharmacokinetic and pharmacodynamic limits. This is a pharmacological boundary, not a delivery obstacle. We conclude that the greatest advances in mRNA 2.0 will come not from delivery alone but from disciplined indication triage by class. Full article

Background: Vaccine acceptance is a fundamental prerequisite for uptake, which may vary over time in response to contextual and vaccine-specific factors and major global disruption. This systematic review and meta-analysis evaluated global trends and determinants of vaccine acceptance between 2009 and 2024. Methods: A comprehensive literature search was conducted using pre-defined keywords and controlled vocabulary related to vaccination, vaccine acceptance or hesitancy, with a broad search strategy designed to capture global evidence across multiple vaccine categories and geographic settings. Studies restricted to high-risk groups or other specific sub-populations (e.g., healthcare workers) were excluded. Studies reporting vaccine acceptance outcomes were systematically identified and pooled estimates were calculated across vaccine categories, WHO regions, income groups, and pandemic periods. Temporal trends and interaction effects were assessed to evaluate changes in vaccine acceptance among different vaccines and before, during, and after the COVID-19 pandemic. Results: A total of 264 publications, including 650,772 participants from 97 countries, were included. Overall, pooled vaccine acceptance was 70.63% and remained relatively stable throughout the study period. Most studies originated from high-income countries, whereas low-income countries and the African region were underrepresented. Childhood vaccines demonstrated the highest pooled acceptance (80.26%), followed by HPV vaccines (66.48%), while influenza vaccines showed the lowest acceptance (52.00%). Childhood vaccine acceptance increased over time and during the COVID-19 period, whereas significant negative interaction trends were observed for HPV and influenza vaccines. Higher vaccine acceptance was observed in African and South-East Asian regions compared with Western Pacific and European regions. Acceptance also varied across income groups, with greater hesitancy generally observed in higher-income settings. Conclusions: Vaccine acceptance among the general population remained relatively stable globally between 2009 and 2024 but varied substantially by vaccine categories, geographic regions, and economic settings. These findings highlight the context-specific nature of vaccine acceptance and the need for harmonized measurement tools and stronger evidence from underrepresented regions to support equitable immunization strategies. Full article

Background: Public acceptance of vaccines during emerging infectious disease outbreaks is influenced by perceptions of safety, accessibility, and cost. Understanding these determinants during the early phase of a pandemic is important for informing vaccination policy and communication strategies. This study examined the role of vaccine cost and safety perceptions in shaping COVID-19 vaccination intention among adults in Saudi Arabia prior to national vaccine rollout. Methods: A cross-sectional electronic survey was conducted among adults residing in Saudi Arabia between August and September 2020. Participants were recruited through online distribution using social media and electronic communication channels. The questionnaire assessed socio-demographic characteristics, knowledge and perceptions regarding COVID-19, and intention to receive COVID-19 vaccination under five hypothetical scenarios reflecting vaccine cost and the availability of scientific safety and efficacy evidence. Multivariable logistic regression analyses were performed to identify factors associated with vaccination intention. Results: A total of 1293 respondents completed the survey. When vaccination was offered free of charge, 57.5% of participants reported that they would likely receive the vaccine. Vaccination intention declined as the hypothetical vaccine price increased, reaching 38.7% when the cost exceeded 100 SAR. Intention was lowest when vaccination was presented under conditions in which safety and efficacy evidence had not yet been confirmed. Age, gender, educational attainment, and prior seasonal influenza vaccination were associated with COVID-19 vaccination intention across several scenarios. Conclusions: Perceived vaccine affordability and confidence in scientific safety and efficacy evidence were important factors associated with COVID-19 vaccination intention during the early phase of the pandemic in Saudi Arabia. Providing vaccination without direct cost to recipients and communicating safety and efficacy evidence transparently may support public confidence and vaccine acceptance during future large-scale immunization campaigns. These findings should be interpreted as an early-pandemic baseline and should not be extrapolated to current post-rollout attitudes. Full article

Background: Vaccine hesitancy has traditionally been understood as a multifactorial phenomenon shaped by individual beliefs, risk perceptions, and access barriers. However, the COVID-19 pandemic has fundamentally transformed the relationship between citizens, science, and public institutions, raising the question of whether vaccine hesitancy has evolved into a broader form of institutional distrust. Objective: This narrative review synthesizes evidence on vaccine confidence, trust dynamics, misinformation, and post-pandemic attitudes to propose a new conceptual framework, i.e., institutional hesitancy, that reframes vaccine acceptance within the wider context of institutional credibility, transparency, and legitimacy. Methods: We conducted a narrative synthesis of peer-reviewed literature, surveillance reports, and cross-national surveys published between 2015 and 2026, focusing on trust in science, governments, public health agencies, healthcare systems, and regulatory authorities as determinants of vaccination behavior. Results: The evidence consistently demonstrates that institutional trust is among the strongest predictors of vaccine acceptance, often surpassing traditional demographic and knowledge-based variables. The pandemic exposed and amplified pre-existing fractures in the relationship between citizens and institutions, creating a legacy of institutional skepticism that extends beyond COVID-19 vaccines to routine immunization programs, seasonal vaccination campaigns, and future pandemic preparedness. Traditional information-based approaches, which assume that knowledge deficits drive hesitancy, have proven insufficient when trust is compromised. Instead, rebuilding vaccine confidence requires sustained investment in institutional transparency, community engagement, and accountable governance. Conclusions: The post-pandemic era calls for a fundamental reconceptualization of vaccine hesitancy. We propose the institutional hesitancy framework as a complementary lens that shifts the analytical focus from individual knowledge deficits to relational dynamics between citizens and institutions. Addressing this challenge requires moving beyond communication campaigns toward long-term strategies that restore institutional trust and strengthen the resilience of public health systems. Full article

Background/Objectives: Vaccine hesitancy is a complex and growing phenomenon worldwide, posing a serious threat to public health achievement in disease control and prevention. This study aimed to assess willingness to uptake and factors linked to shifts between different categories of willingness and uptake regarding the COVID-19 and influenza vaccines. Methods: Prospective cohort study with a representative sample of 1400 individuals aged ≥60 years residing in mainland Portugal, randomly selected. Two telephone surveys were conducted: one at the start of the 2023/2024 vaccination campaign, assessing patients’ characteristics and willingness for vaccination (using an 11-point Likert scale), and another at the end, assessing vaccination status and reasons for uptake/non-uptake. Results: Shifts were observed among both acceptance and refusal groups—12.93% of the individuals within these categories shifted to an opposite decision. Hesitancy presents divergent attitudes: for the COVID-19 vaccine, 56.50% declined vaccination, while for the influenza vaccine, non-uptake was only 30.60%. Age, presence of chronic disease, level of education, household dimension, and previous uptake of booster doses are significantly associated with shifting attitudes, playing different roles for each category of willingness and uptake outcome. For the acceptance category, non-uptake relates to confidence factors. For hesitancy, non-uptake is mainly due to complacency. For refusal, the decision is influenced by all domains. Conclusions: Vaccine hesitancy remains an important public health concern in the Portuguese population and appears to differ between COVID-19 and influenza vaccination. Attitudes toward COVID-19 and influenza vaccines can vary in all directions over a short period. Acceptance does not guarantee uptake, and refusal can shift towards uptake. These findings highlight the importance of reinforcing public health strategies and interventions for uptake across a population, taking into consideration the specificities of each willingness group. Full article

Objectives: This study aims to assess the acceptance of vaccinations among pregnant women, particularly against influenza, pertussis, COVID-19, and RSV, and to identify factors influencing their willingness to get vaccinated. It also seeks to evaluate the impact of the COVID-19 pandemic on maternal attitudes and behaviors regarding vaccination. Methods: The analysis involved a review of existing literature and studies to evaluate the level of vaccine acceptance among pregnant women before and after the COVID-19 pandemic. Factors contributing to vaccine hesitancy, including misinformation, lack of knowledge, and the influence of healthcare professionals, were examined. Results: The findings indicated that, despite scientific evidence supporting the safety and efficacy of vaccines during pregnancy, public concerns remain about their impact on the developing fetus. The outbreak of the COVID-19 pandemic has increased awareness of the risk of infectious diseases, but at the same time, its impact on vaccination rates among pregnant women is ambiguous and geographically diverse. Misinformation and decreased access to healthcare during the pandemic negatively affected vaccine uptake. Trustworthy information provided by healthcare professionals emerged as a key factor in promoting vaccine acceptance. Conclusions: To improve vaccination rates among pregnant women, it is essential to provide clear, evidence-based information through healthcare professionals, particularly those directly caring for pregnant women. Educational campaigns should address concerns calmly and without judgment, emphasizing the safety and benefits of vaccinations. Enhanced access to healthcare and vaccinations, along with strategic information dissemination, can significantly improve vaccine acceptance during pregnancy. Lessons learned from past pandemics should be incorporated into the development of healthcare strategies aimed at implementing recommended vaccinations for pregnant women in the future. Full article

Background: Adenovirus-vectored vaccines played an important role in the global response to SARS-CoV-2. Adenovirus platforms have many advantages including a simple and readily transferred manufacturing process, low cost, and thermostability. Speed of production of an initial Good Manufacturing Practice (GMP)-compliant batch has, however, been viewed as a limitation of adenovirus vectors relative to mRNA platforms. Production of the initial viral starting material and release testing are key rate-limiting steps. Methods: Production of viral starting material from DNA, and release testing in accordance with regulatory expectations, for first-in-human trials of adenovirus-vectored vaccines. Results: We describe experience of these stages in the production of the first GMP batches for multiple adenovirus-vectored candidates and the adaptations made for ChAdOx1 nCoV-19 (the Oxford COVID-19 vaccine) in early 2020. We also report development of a streamlined approach to starting material generation, enabling initial GMP batch availability within c. 60 days of publication of a new pathogen sequence. Using a New World arenavirus vaccine construct as a proof of concept, we demonstrate reproducible execution of this pipeline, maintaining acceptable infectivity and other quality attributes. Conclusions: We discuss opportunities for additional time savings in the future. This work demonstrates suitability of an adenovirus platform to contribute to the “100 Days Mission” for vaccines against “Disease X”. Full article

Objective: To identify demographic, clinical, and behavioural determinants of COVID-19 vaccination and antiviral uptake in Australia using the Capability, Opportunity, Motivation-Behaviour (COM-B) framework with psychometric validation and LASSO-enhanced variable selection. Methods: Cross-sectional analysis of the 2024 KAB BREATHE survey (n = 5177) of Australian adults, intentionally enriched for risk-stacked (more than 1 chronic condition). Primary outcomes included 2023/2024 COVID-19 booster receipt, future vaccine intentions, vaccine/antiviral beliefs and antiviral uptake. Predictors included demographics, chronic conditions, and domain-specific leave-one-out (LOO) COM-B scores standardised to mean = 0, SD = 1. COM-B domains were assessed using Cronbach’s alpha. Univariate and multivariable logistic regression models were complemented by LASSO penalised logistic regression with 10-fold cross-validation. Results: Among 5177 Australian adults, the mean age was 51.5 years (SD 16.5), 61.4% (3179/5177) were female, and 70.3% (3638/5177) were classified as risk-stacked. Booster uptake declined sharply from 50.8% (2023) to 19.1% (2024). Cronbach’s alpha showed poor internal consistency for Capability (α = 0.006) and Opportunity (α = −0.383) but was acceptable for full Motivation (α = 0.78). In adjusted models, age (aOR 1.02–1.03 per year), medically associated risk factors (aOR 1.66–3.51), and tertiary education (aOR 1.34–1.79) consistently predicted higher uptake and intention. Renting (aOR 0.59–0.78) and current employment (likely inversely associated with age) (aOR 0.73–0.83) were associated with lower uptake across all vaccine outcomes. Adding LOO COM-B scores substantially improved model fit (e.g., 2024 booster AUC 0.73→0.83); Motivation per SD was the strongest predictor (aOR 2.44–4.94 for vaccine outcomes, 1.52–2.49 for antivirals). LASSO models achieved CV-AUCs of 0.78–0.87. Among COVID-positive respondents (n = 2576), only 15.2% received antiviral treatment. Conclusions: Age, clinical risk, and socioeconomic factors, particularly housing tenure and employment status, are key drivers of COVID-19 preventive behaviours (either positively or negatively). The COM-B framework, when corrected for circular prediction and validated via Cronbach’s alpha and LASSO, provides substantial explanatory value. Targeted interventions should address structural barriers faced by renters and younger, employed individuals while leveraging high motivation among older adults and clinically vulnerable groups. Implications for Public Health: These findings support a shift from knowledge-based campaigns towards equity-focused, multi-level public health strategies that address structural barriers to COVID-19 vaccination and antiviral access in Australia. Full article