Nam Y. Huh/AP
The United States is on track to have new COVID-19 reminders starting this fall.
On Monday, drugmakers Pfizer and BioNTech announced that they had asked the Food and Drug Administration to authorize an updated version of their COVID-19 vaccine – this one designed specifically to target the omicron subvariants that are dominant in the United States.
More than 90% of cases are caused by the BA.4 and BA.5 subvariants, which took off this summer, but the vaccines used were designed for the original strain of coronavirus from several years ago.
Pfizer and BioNTech said they submitted preclinical data on the vaccine’s effectiveness to the FDA, but did not share the data publicly.
The new “bivalent” booster – meaning it’s a mix of two versions of the vaccine – will target both the original strain of coronavirus and the BA.4 and BA subvariants. 5 omicron.
If the vaccine is cleared by the FDA, distribution could begin “immediately” to help the country prepare for possible fall and winter outbreaks of the coronavirus, Pfizer CEO Albert Bourla said in a statement.
In accordance with FDA guidelines, the data drugmakers submit represents a departure from what has been used in previous vaccine approvals.
Instead of waiting for human trial results, the FDA has asked drug companies to initially submit only mouse trial results, as NPR reported last week. Regulators will use these results — along with human neutralizing antibody data from previous studies of BA.1 bivalent boosters — to decide whether to allow boosters.
“We’re going to use all of this data that we’ve learned not just from this vaccine but from decades of viral immunology to say, ‘The way to be nimble is we’re going to do these animal studies ‘” Deepta Bhattacharya said. , an immunobiologist at the University of Arizona College of Medicine in Tucson, recently told NPR. “We really don’t go too far on a branch here.”
Pfizer and BioNTech also report that they plan to initiate a safety and immunogenicity study of the bivalent BA4/BA5 vaccine this month.
Earlier this year, vaccine makers presented to US and European regulators an option for a bivalent vaccine targeting an earlier version of the omicron variant, BA.1. While the plan was accepted in the UK, US regulators instead asked companies to update vaccines to target new subvariants.
Scientists say the development of COVID-19 vaccines could go along the lines of flu vaccines, which are changed every year to try to match strains likely to be circulating.
NPR’s Rob Stein contributed to this report.