A Food and Drug Administration advisory committee recently voted to recommend updating the COVID-19 vaccine. But important questions remain: When will it be updated, for whom, and who will pay? Based on past experience, there is little guarantee that the government will have the right answers.
The panel suggested a new vaccine targeted at the currently predominant omicron subvariant. This would replace the bivalent boosters first authorized in August 2022 that target the original virus plus the omicron strains that were once prevalent but are no longer circulating.
Changing the vaccine makes good scientific sense. The virus that causes COVID-19, SARS-CoV-2, has been evolving since 2020. The original variant used in the first vaccines authorized in December 2020 is long gone. There is no point in vaccinating against it, and including it in the bivalent booster may have made the shot less effective due to an immunological phenomenon called imprinting, where repeated exposure to the original viral strain makes the vaccine recipient react more strongly to the original strain than to the more current second strain in the vaccine.
