Study Comparing Efficacy of Pfizer and Moderna Booster COVID Vaccines After Third Dose

A recent scientific paper published in the journal natural microbiologyResearchers replicated two subject trials using the Veterans Affairs (VA) electronic health record (EHR) to determine the efficacy of BNT162b2 or messenger ribonucleic acid (mRNA)-1273 vaccines in United States (US) veterans. We compared the efficacy of the third dose.

study: Comparative efficacy of a third dose of mRNA-based COVID-19 vaccine in US veteransImage Credit: Steve Heap / Shutterstock

Background

Head-to-head comparative studies on the efficacy of a third booster dose of coronavirus disease 2019 (COVID-19) vaccines based on different mRNA technologies are lacking. An ideal comparative efficacy study of an mRNA vaccine should cover racially diverse populations and assess possible differences in vaccines Effectiveness Based on the time the individual completed the primary vaccination series. Most importantly, these studies should describe the timeframe for the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants.

During the current SARS-CoV-2 pandemic, vaccination effectively reduced the burden of severe illness and death from COVID-19. In particular, booster doses of BNT162b2 and mRNA-1273 vaccines counteracted immune compromise and extended protection against the highly contagious novel SARS-CoV-2 variant. In one previous study of 439,684 U.S. veterans, researchers found that both mRNA-1273 and BNT162b2 correlated with the risk of SARS-CoV-2 infection and the prevalence of the SARS-CoV-2 alpha variant. found to reduce severe disease outcomes during the rate.

About research

In the current study, researchers matched recipients of BNT162b2 or mRNA-1273 vaccines in a 1:1 ratio based on risk factors, and for five COVIDs, delta-omin and omikron durations of 16 and 9 weeks, respectively. We estimated comparative efficacy across -19 results:

• reports of SARS-CoV-2 infection,
• reported symptomatic SARS-CoV-2 infection,
• SARS-CoV-2 infection-related hospitalization,
• admission to an intensive care unit (ICU), and
• death.

Veterans in the first emulated trial received a third dose of BNT162b2 or mRNA-1273 vaccine between October 20, 2021 and February 8, 2022. This period corresponded to the prevalence of SARS-CoV-2 delta and omicron variants. For each veteran in the primary analysis, the team began follow-up on the day of his third vaccination (baseline). He ended 16 weeks after baseline, death, or the end of the study period, i.e., February 15, 2022.

A second emulated study veterans cohort received a third dose of either of the two mRNA COVID-19 vaccines between 1 January and 1 March 2022. During this period, only Omicron was dominant. Median follow-up lasted over 9 weeks, during which the team recorded 214 SARS-CoV-2 infections.

Survey results

In the first emulated trial, 147,553 and 214,728 veterans received a third dose of BNT162b2 and mRNA-1273, respectively. Baseline characteristics of 65,196 of her BNT162b2 recipients matched with the same number of mRNA-1273 recipients were comparable compared to the eligible population. The median age of this veteran was 70, he was 96% male and 24% black.

During a 16-week follow-up that spanned Delta and Omicron prevalence, researchers documented 2,994 SARS-CoV-2 infections. Of these, 200 were symptomatic COVID-19 cases, 194 sought hospitalization, 52 required ICU admission, and 22 resulted in death. During this period, the estimated risks of infection reported for her third dose of BNT162b2 and mRNA-1273 were 353.9 and 308.5 events per 10,000, respectively.

In a second emulated trial, 25,557 and 36,809 eligible veterans received a third dose of BNT162b2 mRNA-1273, respectively. As in the first trial, the matched population consisted of 7,894 His BNT162b2 and similar numbers of mRNA-1273 recipients with comparable baseline demographic and clinical characteristics compared to the eligible population. was They were predominantly male and white.

During the 9-week follow-up in the preponderance of Omicron, the estimated risk of documented SARS-CoV-2 infection was higher with the third dose of BNT162b2 vaccine than with mRNA-1273. Therefore, the estimated risk ratio is 1.57, displayed as events per 10,000 people.

Conclusion

This study demonstrated the comparative efficacy of a third (booster) dose of two mRNA vaccines, BNT162b2 and mRNA-1272, prominently in a national cohort of US veterans. Both vaccines reduced the absolute risk of breakthrough SARS-CoV-2 infection and severe consequences of his COVID-19. However, mRNA-1273 vaccinees were at greater risk of COVID-19-related adverse events than mRNA-1273 vaccinees at 16-week follow-up, especially in the case of reported SARS-CoV-2 infection. was low. Findings were comparable over periods spanning Delta and Omicron dominance, and Omicron dominance only. The authors advocated continuous evaluation of the comparative efficacy and safety of additional (booster) doses of COVID-19 mRNA vaccines in the future.