A new pre-print study published in Medrxiv Preprint server found that a third dose of an mRNA COVID-19 vaccine from Pfizer or Moderna may not boost their protection against the Omicron variant of SARS-CoV-2 in people with previous infection.
The goal of the study was to estimate the effectiveness of primary and booster vaccination against the Omicron variant among people with a prior documented COVID-19 infection.
Researchers estimated the effectiveness of primary and booster vaccination in nearly 130,000 people who tested for SARS-CoV-2 in Connecticut from November 2021 through January 2022, including 10,676 with Omicron infections
While primary COVID-19 vaccination provided protection against BA.1 infection among people with and without prior infection, the authors found that booster vaccination was only associated with additional protection in people without prior infection.
The researchers conclude that their findings support primary vaccination in people regardless of prior infection status but that they “did not detect an additional benefit of receiving a third booster dose among this population,” suggesting that infection history should be considered when evaluating the need for booster vaccination.
It is worth mentioning that among the authors of this study, there are researchers with ties to Biopharmaceutical Companies, like Regeneron and Merk, and that Merck and Co is listed as one of the funding sources.
