By Michael Erman
NEW YORK (Reuters) – A top scientist from Pfizer Inc. said on Thursday that the company is in intensive talks with regulators to test a version of its coronavirus vaccine, specifically targeting an extremely contagious variant that is widespread in the South. -Africa and elsewhere.
A laboratory study released on Wednesday suggested that the South African virus variant could reduce protective antibodies elicited by the Pfizer / BioNTech vaccine by two-thirds, but it is not clear how much the effectiveness of the shot against this version of the pathogen is not reduced.
Phil Dormitzer, one of Pfizer’s leading viral vaccine scientists and co-author of the study, said in an interview that he believes the current vaccine is likely to continue to protect against the particular variant first discovered in South Africa.
” A level of neutralizing antibodies that is between one-third and one-half level is the level of neutralizing antibodies you see against the original virus, does not mean that you have only one-third to one-half of the level of protection. protection, ”he said.
Pei-Yong Shi, a professor at the University of Texas and co-author of the study, said he also believes the diminished immune response is likely to be significantly higher than it should be to provide protection.
Shi said that both the Pfizer / BioNTech vaccine and a similar inclusion of Moderna Inc in clinical trials provide some protection after the first of two doses with an antibody response lower than the reduced levels shown in the South laboratory study. -Afrikaans variant has been seen.
Dormitzer, chief scientific officer for viral vaccines at Pfizer Vaccines Research and Development, said the company is considering plans to test a redesigned booster for the vaccine.
“We are not doing this primarily because we think it means we have to change the vaccine,” he said. ‘It’s mainly about learning how to change stress, in terms of what we do at the manufacturing level and especially what the clinical results are.
“So if there is a variant for which clinical evidence of escape exists, we are ready to respond quickly,” Dormitzer added.
He said the company has already made a DNA template for a prototype vaccine targeted at the variant and plans to manufacture a batch of it.
The company proposes to conduct a phase I clinical trial of an enhancer uptake of the prototype vaccine that will test the current vaccine against an enhancer.
“This will be an immunogenicity study where you look at the immune response. And these studies are much, much smaller than the giant efficacy studies,” Dormitzer said.
“In immunogenicity studies, you can look at the immune response of each person in the study. It is certainly not as definitive as efficacy data. But it can be collected much faster,” he explained.
The company is also likely to conduct parallel animal testing, he said.
The U.S. Food and Drug Administration has not yet released a roadmap on how companies should design trials with coronavirus enhancements.
(Reporting by Michael Erman; Editing by Caroline Humer and Bill Berkrot)