Social network,Biden approval,and pediatric COVID-19 vaccine uptake

This study aims to estimate the pediatric COVID-19 vaccine uptake and the impact of social network and Biden approval. A national survey was conducted by Qualtrics from September 26 to 19 October 2022, and respondents who identified as primary guardians of children under 18 are included in this study. Findings show that parents are more likely to vaccinate children between 12 and 17 than children between 5 and 11 or below 5. The means of measures for social network and Biden approval for parents who have vaccinated children across different age groups are significantly higher than the corresponding means for parents whose children remain unvaccinated. Structural equation modeling results suggest the social network and Biden approval positively affect parents' decision to vaccinate children. The former predictor also mediates the latter on the outcome measure. The findings are significant when analyzing the sample of parents with children over five. These findings contribute to the literature and have policy implications for leveraging interventions and optimizing vaccination for children.     

Combining evidence from clinical trials in conditional or accelerated approval

Conditional (European Medicines Agency) or accelerated (U.S. Food and Drug Administration) approval of drugs allows earlier access to promising new treatments that address unmet medical needs. Certain post-marketing requirements must typically be met in order to obtain full approval, such as conducting a new post-market clinical trial. We study the applicability of the recently developed harmonic mean ${\chi }^2$-test to this conditional or accelerated approval framework. The proposed approach can be used both to support the design of the post-market trial and the analysis of the combined evidence provided by both trials. Other methods considered are the two-trials rule, Fisher's criterion and Stouffer's method. In contrast to some of the traditional methods, the harmonic mean ${\chi }^2$-test always requires a post-market clinical trial. If the $p$-value from the pre-market clinical trial is $\ll 0.025$, a smaller sample size for the post-market clinical trial is needed than with the two-trials rule. For illustration, we apply the harmonic mean ${\chi }^2$-test to a drug which received conditional (and later full) market licensing by the EMA. A simulation study is conducted to study the operating characteristics of the harmonic mean ${\chi }^2$-test and two-trials rule in more detail. We finally investigate the applicability of these two methods to compute the power at interim of an ongoing post-market trial. These results are expected to aid in the design and assessment of the required post-market studies in terms of the level of evidence required for full approval.