- Moderna has joined Pfizer in asking the Food and Drug Administration for emergency authorization of a new COVID-19 booster shot adapted to the virus strains now dominant in the U.S.
- The biotech’s reformulated shot targets both the original coronavirus strain and the BA.4/BA.5 omicron subvariants. BA.5 now accounts for almost 90% of cases in the U.S., with versions of BA.4 making up almost all of the rest, according to estimates from the Centers for Disease Control and Prevention.
- Moderna and Pfizer have been working closely with the FDA to design boosters that can better fend off COVID-19, particularly as immunity wanes in people who were last vaccinated many months ago. On Monday, Pfizer announced it had finished its application. Moderna followed a day later.
The updated vaccines are a key part of the Biden administration’s plan to control COVID-19 ahead of an expected new wave of cases in winter when more people will spend time indoors. The government has earmarked billions of dollars to secure supplies of both inoculations, which it said could be available as soon as early September.
The regulatory process to meet that timeframe, however, is a bit of a high-wire act. Neither Pfizer nor Moderna have clinical trial results on the versions of the shots they have submitted. Instead, they are relying on preclinical and manufacturing data, as well as human studies of vaccines that incorporated the BA.1 omicron strain.
Those studies began months ago, before BA.4 and BA.5 became dominant, and showed better performance against omicron than the companies’ currently available shots. Moderna in June and again in July said its “bivalent” BA.1 booster shot provoked a significantly stronger response against omicron in patients than its original vaccine.
The U.K. earlier this month approved that shot. But after consultations with outside experts, the FDA determined that focusing on BA.1 wasn’t enough for the new generation of vaccines and advised drugmakers they should include a BA.4/5 component in shots for the fall season.
Even without the new component, available vaccines continue to have a dramatic effect on reducing death and hospitalization from COVID-19.