This updated formulation will combine the original vaccine with one that targets Omicron sublineages BA.4 and BA.5, and would be administered as a 30 microgram dose.
The companies say they are following “guidance from the FDA” and are including clinical data of their bivalent BA.1 vaccine and pre-clinical and manufacturing data from the bivalent BA.4/5 vaccine for the submission.
“FDA will be using the totality of the available evidence to authorize the fall bivalent boosters,” FDA spokesperson Abigail Capobianco said in a statement emailed to CNN last week. “There are data on many millions of individuals who have received the prototype component as a booster. As for the BA.4/5 component, a combination of nonclinical data obtained in mice, data from prior variant vaccines (including those to beta, delta, and omicron BA.1), along with our extensive knowledge of the safety and efficacy of the mRNA platforms will be used for this decision-making.”
Pre-clinical data demonstrated that the new BA.4/5 bivalent vaccine “generated a strong neutralizing antibody response against Omicron BA.1, BA.2 and BA.4/BA.5 variants, as well as the original wild-type strain,” according to the companies. They said a clinical study is expected to start this month.
Previously, the companies announced data from a Phase 2/3 trial that showed their BA.1 bivalent booster resulted in a substantially higher immune response against the Omicron variant and also appeared to be safe and well tolerated.
When could shots be available?
White House Covid-19 Response Coordinator Dr. Ashish Jha said recently the updated boosters should be available to the public early- to mid-September. but it is ultimately up to the FDA as to when the shot will get the greenlight.
The agency will now evaluate Pfizer and BioNTech’s data, but hasn’t said whether it will convene its vaccine advisers before making a decision on authorization. Such a step could push back when shots can be administered.
Production of the updated shots is already underway. The US government has purchased 105 million bivalent Covid-19 vaccine booster doses from Pfizer, and another 66 million updated shots from Moderna.
Pfizer and BioNTech say have “rapidly scaled production and stand ready to deliver doses of Omicron BA.4/BA.5-adapted bivalent vaccines for September, and will begin shipping immediately pending authorization.”
“The agility of the mRNA platform, together with extensive clinical experience with the Pfizer-BioNTech COVID-19 Vaccine, has allowed us to develop, test and manufacture updated, high-quality vaccines that align to circulating strains with unprecedented speed,” said Albert Bourla, Pfizer’s chairman and chief executive officer, in the statement.