New York: 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.Phil Dormitzer, one of Pfizer's top viral vaccine scientists, said in an interview that he believes the current vaccine - developed with Germany's BioNTech SE - is highly likely to still protect against the concerning variant first discovered in South Africa."We're not doing that primarily because we think that 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.