Washington (AFP) - US officials Wednesday authorized updated Covid-19 vaccinations by Moderna and Pfizer-BioNTech that specifically target the latest strains of the Omicron variant, hoping to contain a new wave of feared contagions this winter.
The two new booster shots are approved for people age 12 and above for the Pfizer shot and 18 and older for Moderna, the Food and Drug Administration (FDA) said in a statement.
This new generation of so-called "bivalent" vaccines protects against both the original strain of Covid and the BA.4 and BA.5 lineages -- the subvariants of Omicron which account for about 90 percent of all new cases in the United States.
"Although the current Covid-19 surge is waning overall, it's predicated that we'll enter yet another surge as we spend more time indoors later this fall and winter," FDA Commissioner Robert Califf told reporters.
"These update boosters present us with an opportunity to get ahead" of the curve, he said.
While the intense focus on coronavirus has largely faded from daily life for Americans, the United States still records some 80,000 new cases -- and 400 deaths -- from Covid every day.
Earlier this summer the US health department announced it had purchased 105 million doses from Pfizer and 66 million from Moderna for use over the fall and winter.
The vaccines must still receive a recommendation by the Centers for Disease Control and Prevention, the nation's health protection agency, before injections can begin.
An independent panel of experts is scheduled to be convened by the CDC on Thursday to discuss the updates.
Low booster uptake
The two companies indicated their updated vaccines could be available for distribution in the United States as early as next week.
"Receiving a booster that specifically targets the Omicron BA.4/.5 variant...is an important public health measure that people can take to help protect themselves," Moderna chief executive Stephane Bancel said in a statement.
Many Americans will need convincing to take the new shots, as how only about half of those eligible have received a first booster dose.
The vaccines currently in circulation target the initial strain of the virus that first appeared in Wuhan, China.They have gradually proven to be less effective against the variants that have appeared over time, due to rapid evolution of the virus.
The FDA still recommends people get the original vaccine in order to receive "a foundation of that basic immune response," Califf said.
In contrast to the Alpha and Delta variants, which eventually waned, Omicron and its subvariants have come to dominate infections worldwide in 2022.
Pfizer and Moderna have also filed for approval of their updated vaccines with the European Medicines Agency.