First boosters, second boosters, monovalent, bivalent… The vaccines to combat the SARS-CoV-2 virus are always changing. Yet, which are the most effective?
To assess the variety of vaccines, their effectiveness, and the methods used to study vaccines’ effectiveness, University of Michigan researchers, led by Sabir Meah and Bhramar Mukherjee, have evaluated some 80 studies and 150 million observations from patient datasets across the world.
Following this, the researchers applied each method used in these studies to patient data from Michigan Medicine.
“What we have been able to create is a repository of methods that can be applied for future annual vaccines,” Mukherjee states in a research note sent to Digital Journal. “It is important to have robust and reproducible results and reliable estimates of vaccine effectiveness to solidify public trust and fight misinformation.”
Meah adds: “What we have been able to do is to establish an analytic pipeline where researchers can study the vaccine effectiveness of future annual vaccine formulations.”
In terms of vaccine effectiveness, Meah is very clear: “COVID-19 vaccines examined in our study, including the fall 2022 bivalent vaccine, provided strong protection against hospitalization and death. We expect this pattern to continue with additional annual vaccines approved by the FDA, but continued study of future vaccines is warranted, and our findings provide some important points of consideration for these future studies.”
Meah explains more:
“In our study, we evaluated three different vaccination regimens: 1) the monovalent booster targeting the original strain, 2) the second monovalent booster also with the original formulation, and 3) the new bivalent vaccine updated in fall 2022 to target newer Omicron variants. We saw that all sequential doses provided a substantial benefit in terms of preventing hospitalization and death, and the estimates from the fall 2022 Omicron specific vaccine dose were stronger from worldwide studies we looked at.”
From this assessment, Meah found: “These findings support the practice of periodically updating the COVID-19 vaccines for currently circulating variants. Fortunately, it appears that in the U.S. and many other countries, such as those in the European Union, we will be getting updated COVID-19 vaccines on an annual frequency.”
The approach used was based on biostatistics and epidemiology. Meah explains how these approaches “provide a toolbox for the complex process of evaluating vaccine effectiveness in scientific observational studies.”
The full study has been published in the journal Science Advances. The research is titled “Design and analysis heterogeneity in observational studies of COVID-19 booster effectiveness: A review and case study.”
