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It’s Science: Should you get the Omicron-specific boosters?


There’s no doubt that the current COVID-19 boosters from the original prototype vaccines based on the ancestral SARS-CoV-2 index virus strain, continue to protect people against serious illness and death. So why did the recent FDA advisory committee recommend inclusion of a SARS-CoV-2 Omicron component for COVID-19 booster vaccines this fall?

Specifically, the FDA authorized that vaccine manufacturers add a spike protein component of the Omicron subvariants BA.4 and BA.5 to their prototype vaccines to make bivalent boosters that can be used beginning this fall. At the same time, the vaccine manufacturers will not be changing the formulation for primary vaccination, since a primary series with the FDA-approved COVID-19 vaccines provide a base of protection against serious outcomes of COVID-19 caused by circulating strains of SARS-CoV-2.

The problem with such a quickly evolving virus is that we don’t know if the proposed BA.4-BA.5 bivalent vaccine proposed for use this fall will trigger the same immune response as the BA.1 bivalent vaccines for which we have actual data. The challenging truth of vaccine development in the realm of public health policy is that while we need targeted Omicron-specific vaccines for increased protection, we just don’t have the time to accumulate the necessary data and we can’t accurately predict which variants will be predominant this fall and winter.

This results in confusing public health messaging giving rise to the unrealistic expectation that COVID-19 vaccines are supposed to prevent all SARS-CoV-2 infection. At the same time, we can reasonably assume that inclusion of Omicron-specific variants increase the breadth of the immune response and this is important as we know the newer variants are capable of immune escape.

One intriguing solution is the development of a “pancoronavirus vaccine” in which an immune cell presented with several mosaic versions of a protein make compromise antibodies that work against multiple coronaviruses. Recent studies at Duke University describe work in which immunization with a multimeric SARS-CoV-2 receptor binding domain (RBD) nanoparticle elicited cross-neutralizing antibody responses against a host of coronaviruses.

Researchers at the Walter Reed Army Institute of Research (WRAIR) are working on a “pan-SARS” vaccine that anticipates variants of concern that could emerge in the future. These results demonstrate the potential for a pancoronavirus vaccine to provide protection from current and future coronavirus variants and may obviate the need for seasonally-adjusted vaccine variant boosters.

In the meantime, get your recommended primary vaccine and boosters to avoid hospitalization and death that has already killed over 1 million in the United States.

David Segarnick Ph.D. is chief medical officer and executive vice president for MedEvoke (an iNIZIO company) in Lebanon, N.J., and assistant professor, pharmacology, physiology and Neuroscience, Rutgers Medical School, Newark. He lives in Upper Black Eddy.