A team of University of Michigan researchers conducted an analysis of over 80 studies to evaluate the effectiveness of COVID-19 vaccine doses beyond the primary series. Based on 150 million patient observations, their findings support the efficacy of both monovalent and bivalent boosters in preventing severe outcomes, emphasizing the importance of annual vaccine updates. The study highlighted the significant benefits of monovalent and bivalent COVID-19 boosters in preventing hospitalization and death, advocating for the periodic update of vaccines to match circulating virus variants. This research aims to better understand the variety of vaccines, their effectiveness, and the methods used globally to study vaccines’ effectiveness.
The team, led by Sabir Meah and Bhramar Mukherjee, evaluated 80 studies and 150 million observations from patient datasets across the world to understand the various designs and methods used to study effectiveness of COVID-19 vaccine doses following the primary series vaccination. Meah, a School of Public Health alumnus with a master’s degree in Biostatistics and currently a biostatistician in Urology at Michigan Medicine, and Mukherjee, the John D. Kalbfleish Distinguished University Professor of Biostatistics, the Sioban Harlow Collegiate Professor of Public Health, and assistant vice president for research in the Office of the Vice President for Research, aimed to create a repository of methods that can be applied for future annual vaccines. Meah further explained the findings around bivalent and monovalent boosters, highlighting the substantial benefit in terms of preventing hospitalization and death provided by all sequential doses and the stronger estimates from the fall 2022 Omicron-specific vaccine dose.
The researchers found that the continuous updating of COVID-19 vaccines for currently circulating variants is important. Their conclusions suggest that the utility of updating vaccines should generalize to any updated COVID-19 vaccine. However, additional monitoring and study of the real-world effectiveness of an annual vaccine is necessary.
Biostatistics and epidemiology provide a toolbox for the complex process of evaluating vaccine effectiveness in scientific observational studies. Meah emphasized that their study found vaccine effectiveness estimates to remain stable for the outcomes of hospitalization and mortality, making these outcomes important points of study as we transition into the endemic stage of the pandemic.
The study concludes that COVID-19 vaccines, including the fall 2022 bivalent vaccine, provided strong protection against hospitalization and death. The researchers expect this pattern to continue with additional annual vaccines approved by the FDA, but they stress the need for continued study of future vaccines and the importance of their findings for these studies. The study is detailed in Science Advances.
