Drugmakers Told to Retool Boosters

"U.S. health regulators have directed vaccine manufacturers to modify their Covid-19 shots to better target the recently circulating offshoots of the Omicron variant in preparation for a fall booster campaign.

The Food and Drug Administration said Thursday it advised companies including Pfizer Inc. and Moderna Inc. to make new vaccines that target the ancestral strain of the coronavirus, plus the Omicron subvariants BA.4 and BA.5.

The subvariants have been spreading rapidly around the U.S., and have been able to partly elude even shots modified to target the original Omicron subvariant that the drugmakers have been working on.

The agency's direction toward BA.4 and BA.5-targeted shots should result in the first changes to the composition of the Covid-19 vaccines since they began rolling out in the U.S. in December 2020, and will kick off a frantic race to develop the shots specified.

The FDA said the modified vaccines could potentially be used starting in early to mid-fall. The FDA indicated it may authorize the shots before results of human testing of such shots are known. This would be similar to the process FDA uses for annual updates to seasonal flu shots.

"As we move into the fall and winter, it is critical that we have safe and effective vaccine boosters that can provide protection against circulating and emerging variants to prevent the most severe consequences of Covid-19," said Peter Marks, who directs the FDA division overseeing vaccines.

The changes would be made to booster shots, not the initial vaccine doses.

The new FDA directions would force vaccine makers to pivot quickly to focusing on the subvariants, because they have been focused on new shots targeting the original Omicron strain since it emerged late last year.

The two Omicron subvariants represented a combined 52% of Covid-19 cases in the U.S. for the week ended June 25, according to estimates the Centers for Disease Control and Prevention released on Tuesday. The original Covid-19 vaccines have been shown to be less effective against Omicron.

Pfizer, with its partner BioNTech SE, and Moderna have been testing modified shots that target the original Omicron variant, which first emerged in late 2021. The companies said these shots improved people's immune responses to the Omicron variant in studies.

Pfizer Chief Executive Albert Bourla said on Twitter that the company's vaccine mRNA technology "enables us to quickly update our vaccine constructs as new strains become more prominent, and we are ready to immediately implement this process."

Kathrin Jansen, the company's head of vaccine research, said Tuesday during a meeting of FDA advisers recommending modification of Covid-19 shots, that the company is prepared to deliver updated shots by early October. Dr. Jansen also said Pfizer was in the process of producing vaccines targeting BA.4 and BA.5.

Moderna said in a Twitter post it will develop a "bivalent" booster targeting BA.4 and BA.5 as well as the ancestral coronavirus strain, in addition to its bivalent shot targeting the original Omicron subvariant." [1]

1. U.S. News: Drugmakers Told to Retool Boosters
Loftus, Peter; Hopkins, Jared S. 
Wall Street Journal, Eastern edition; New York, N.Y. [New York, N.Y]. 01 July 2022: A.3.