FDA authorizes Covid-19 booster shots retooled to tackle Omicron subvariants

The US Food and Drug Administration (FDA) on Wednesday authorized retooled Covid-19 booster shots made by both Moderna and Pfizer/BioNTech to target the currently dominant BA.4/BA.5 Omicron subvariants of the coronavirus.

Both vaccines also include the original version of the virus targeted by all previous Covid shots as the US prepares for another vaccination campaign in the fall.

The US government has purchased 175m doses of the booster shots in an effort to stave off the worst effects of a potential surge in new infections as schools reconvene and people spend more time indoors as the weather grows colder.

In June, the FDA asked vaccine makers to tailor shots to the two subvariants responsible for the most recent surge in infections worldwide. The BA.5 subvariant currently accounts for more than 88% of US infections.

Individuals who receive the bivalent booster shot may experience side effects commonly reported by those that received monolanent Covid-19 vaccines, the FDA said.

The Centers for Disease Control and Prevention (CDC) vaccine advisory panel is scheduled to meet on Thursday to make recommendations for use of the redesigned shots. The CDC director, Rochelle Walensky, will take the recommendations into consideration before making a final decision.

Currently, 79% of the US population has received at least one dose and 67% is considered fully vaccinated. Only 33% of Americans have received a booster dose.