A top Pfizer Inc scientist said on Thursday the company is in intensive discussions with regulators to test a booster shot version of its coronavirus vaccine specifically targeted for a highly contagious variant that is spreading widely in South Africa and elsewhere.
A laboratory study released on Wednesday suggested that the South African virus variant may reduce protective antibodies elicited by the Pfizer/BioNTech vaccine by two-thirds, but it is not clear how much that reduces the shot’s effectiveness against this version of the pathogen.
Phil Dormitzer, one of Pfizer’s top viral vaccine scientists and a co-author of the study, said in an interview he believes the current vaccine is highly likely to still protect against the concerning variant first discovered in South Africa.
“A level of neutralizing antibodies that may be on the order of between a third and a half the level of neutralizing antibodies you see against the original virus does not mean you have only a third to half of the protection level, you may well have full protection,” he said.
Still, Dormitzer, chief scientific officer of viral vaccines at Pfizer Vaccines Research and Development, said the company was developing plans to test a redesigned booster for the vaccine.
“We’re not doing that primarily because we think that means that we’re going to need to change that vaccine,” he said. “It’s primarily to learn how to change strain, both in terms of what we do at the manufacturing level, and especially what the clinical results are.
“So if a variant comes along for which there is clinical evidence of escape, we’re ready to respond very quickly,” Dormitzer added.
He said the company has already made a DNA template for a prototype vaccine targeting the variant and plans to manufacture a batch of it.
The company is proposing to do a Phase I clinical trial of a booster shot of that prototype vaccine that it would test against a booster for the current vaccine.