Coronavirus vaccines: signs of weaker response to new strains in South Africa, Brazil



Coronavirus variants emerging from the southern hemisphere can weaken the most powerful vaccines but people should still have the shots to guard against severe disease, according to researchers.In a non-peer-reviewed study published last week, a team in Boston found a drop in the amount of the mutated South Africa strain neutralised by antibodies induced by the Pfizer-BioNTech and Moderna vaccines of between 75 and 97-fold. The drop was 13-fold against another strain circulating in Brazil…