Fears over South African Covid variant
Scientists are increasingly concerned that a new coronavirus variant linked to an explosion of cases in South Africa could make existing Covid-19 vaccines less effective. First detected in August, the variant is more infectious than most previous forms of the virus and has accelerated a second wave of the disease in South Africa. The strain shares several mutations with a separate fast-spreading variant that was discovered in the U.K. in December and has since shown up in the U.S. Scientists suspect the South African variant is no deadlier than other existing strains of the disease. What worries researchers is that the South African variant has a unique mutation in its “receptor binding domain”—part of the spike protein that the virus uses to enter cells. That’s also a key site where neutralizing antibodies, generated in response to an infection or a vaccination, latch on to the virus. One new study, which hasn’t yet been peer reviewed, found that in some people this mutation reduces the disease-blocking abilities of antibodies that target earlier strains of the virus. “At this moment, we think that a vaccine could be a little less effective,” lead researcher Tulio de Oliveira, from the University of KwaZulu-Natal, tells the Financial Times. But “between all the varieties of vaccines that are coming to the market, we still have strong belief that some of them will be very effective.”