An advisory panel to the US Food and Drug Administration is to meet this week to discuss whether updated booster vaccines for COVID-19 should be recommended for authorization, the New York Times reports.
Earlier this month, Moderna said that its bivalent vaccine led to an eight-fold increase in neutralizing antibodies against the Omicron variant, a stronger response than its initial vaccine targeting only the original SARS-CoV-2 strain. Pfizer similarly said this weekend that its bivalent vaccine also led to an increase in immune response — a 13.5- and 19.6-fold increase, depending on dose, in neutralizing antibodies — to the Omicron variant, as CNN reports.
However, the Times notes that these updated vaccines may already be a step behind the virus. Omicron appears to be waning as its subvariants BA.4 and BA.5 are on the rise and currently account for nearly a third of US COVID-19 cases, it says. The Wall Street Journal adds that Moderna's bivalent booster appears less effective against the BA.4 and BA.5 subvariants. "It becomes a game of whack-a-mole," Ted Tenthoff from Piper Sandler tells it. "As the virus evolves away from Omicron, you will have less immunogenicity."
Because of this, the Times says that federal regulators may instead push for an updated vaccine booster that instead targets these variants, but that may mean having to rely on data from animal studies and lab tests to turn the vaccines around fast enough.
The Journal adds that Congress has also yet to provide funding for these booster shots.