Inequity in the access to and deployment of the coronavirus disease 2019 (COVID-19) vaccines has brought about great challenges in terms of resolving the pandemic. Aiming to analyze the association between country income level and COVID-19 vaccination coverage and explore the mediating role of vaccination policy, we conducted a cross-sectional ecological study. The dependent variable was COVID-19 vaccination coverage in 138 countries as of May 31, 2021. A single-mediator model based on structural equation modeling was developed to analyze mediation effects in different country income groups. Compared with high-income countries, upper-middle- (β = −1.44, 95% CI: −1.86–−1.02, p < 0.001), lower-middle- (β = −2.24, 95% CI: −2.67–−1.82, p < 0.001), and low- (β = −4.05, 95% CI: −4.59–−3.51, p < 0.001) income countries had lower vaccination coverage. Vaccination policies mediated 14.6% and 15.6% of the effect in upper-middle- (β = −0.21, 95% CI: −0.39–−0.03, p = 0.020) and lower-middle- (β = −0.35, 95% CI: −0.56–−0.13, p = 0.002) income countries, respectively, whereas the mediation effect was not significant in low-income countries (β = −0.21, 95% CI: −0.43–0.01, p = 0.062). The results were similar after adjusting for demographic structure and underlying health conditions. Income disparity remains an important cause of vaccine inequity, and the tendency toward “vaccine nationalism” restricts the functioning of the global vaccine allocation framework. Stronger mechanisms are needed to foster countries’ political will to promote vaccine equity.

(1) Objectives: Inequality in the global distribution of COVID-19 vaccines has brought about great challenges in terms of resolving the pandemic. Although vaccine manufacturers are undoubtedly some of the most influential players, studies on their role in global vaccine distribution have been scarce. This study examined whether the pharmaceutical industry is acting according to the principles of corporate social responsibility (CSR) during the pandemic. (2) Methods: Three categories were used to analyze the CSR of vaccine developers. The first was research and development: effectiveness, funding, and profits were measured. The second was transparency and accountability: the transparency of clinical trials and vaccine contracts was analyzed. The final was vaccine delivery: the status of the provision of vaccines to COVAX and lower-income countries, intellectual property management, manufacturing agreements, and equitable pricing were measured. (3) Results: Vaccine developers have acquired large profits. The vaccine delivery category faces the most challenges. Participation of pharmaceutical companies through COVAX was significantly low, and most vaccine supply agreements were secretive, bilateral deals. It was not clear if companies were maintaining equitable pricing. The evaluation indicated that the companies’ CSR practices have differed during the pandemic. (4) Conclusions: Our study contributes to the methodology of assessing the CSR of vaccine developers. This would help understand the current COVID-19 vaccine distribution inequality and propose that pharmaceutical companies re-examine their roles and social responsibilities.

Background/Objectives: Few paediatric obesity trials have examined behavioural mediators of intervention effects on detailed body composition outcomes beyond body mass index (BMI). Given the complexity of multiple correlated body composition indicators, this study aimed to employ principal component analysis (PCA) to derive a composite adiposity factor and to apply mediation analysis to identify whether changes in dietary behaviours and physical activity mediated the effects of the DECIDE-Children intervention on body composition. Methods: This study included 1180 children from a 9-month cluster-randomised controlled trial that delivered a multifaceted, digitally assisted intervention targeting children (health education, physical activity reinforcement, and app-based BMI monitoring/feedback) and their environments (school food policies and family engagement). Outcomes were changes in body composition (whole-body and trunk fat mass, fat-free mass, and muscle mass indices measured by bioelectrical impedance analysis). Potential mediators included changes in dietary behaviour, screen time, and moderate-to-vigorous physical activity (MVPA), assessed via validated questionnaires. PCA was used to reduce the dimensionality of body composition variables and to derive a composite adiposity factor (PCA_1), with higher values indicating greater adiposity and lower muscle mass. Mediation was tested using linear mixed-effects models adjusted for age, sex, and region. Results: The intervention significantly reduced adiposity indicators (e.g., whole-body and trunk fat mass percentage decreased by 1.003%, and PCA_1 decreased by 0.942 SD) and concurrently increased fat-free mass percentage and muscle mass percentage at both whole-body and trunk levels. Dietary behaviour significantly mediated the intervention effects on all body composition outcomes (e.g., mediating 16.1% of the effect on PCA_1), whereas physical activity (both screen time and MVPA) showed no mediation. Sensitivity analyses supported the primary findings. Conclusions: The DECIDE-Children intervention improved body composition by reducing adiposity and increasing fat-free and muscle mass percentage, effects primarily mediated by dietary behaviour. These findings highlight dietary behaviour as a key component in paediatric obesity intervention.