Moderna to test different booster shot against South Africa coronavirus variant

Moderna is weighing a second booster shot to battle back a new coronavirus variant, even as it affirms its current vaccine's activity against newly emerging mutants. While the current two-dose regimen is holding so far, it's less effective against a South African variant—which has the company exploring a third shot and a variant-specific booster. The variant candidate is moving into preclinical studies and a phase 1 U.S. study, targeting the coronavirus strain first identified in South Africa, Moderna said Monday. The South African variant, known as B.1.135, notched a sixfold reduction in neutralizing titers in tests made by Moderna and the National Institute of Allergy and Infectious Diseases (NIAID). Despite the decrease, the vaccine maintained levels expected to protect vaccine recipients, Moderna said.