UK Covid variant extremely unlikely to evade vaccines, scientists say
The new coronavirus variant that is sweeping the UK is extremely unlikely to evade immune responses generated by vaccines or a previous Covid infection, scientists say.
Researchers in the US found that antibodies collected from former patients very rarely targeted parts of the virus that were mutated in the new variant. Their work suggests only 0.5% of individuals are at risk of having reduced protection against the variant, named B.1.1.7.
The findings will come as a relief to scientists and public health officials who have been concerned that vaccines being rolled out worldwide might be less effective against the new variant, and that cases could soar on the back of reinfections.
Based on the new analysis, Akiko Iwasaki, a professor of immunobiology at Yale University, said: “The B.1.1.7 variant is unlikely to escape recognition by antibodies generated by prior infection with [older versions of the] virus or the vaccines.”
Iwasaki teamed up with Winston Haynes and others at the California biotech firm Serimmune to investigate how antibodies in the blood of Covid-19 patients target the virus. Antibodies disable viruses by sticking to the proteins from which they are made. Some target continuous strands of protein, like a handful of consecutive words in a sentence, while others latch on to bits of protein that are brought together when they loop and fold.
The scientists collected antibodies from 579 coronavirus patients and looked at which continuous strands of virus protein they targeted. The vast majority attacked the same “hotspots” of the virus. Crucially, none of the mutations in the new UK variant are in these hotspots, so most people’s antibody defences will not be weakened.
One of the most important parts of the virus is the spike protein, a strand of 1,273 molecules called amino acids that link together in a chain. The spike acts like a key for the virus to infect cells and is also the target of most vaccines. In the study, which has yet to be peer reviewed, Iwasaki and her colleagues found that only two people, or 0.3% of the patients studied, had antibodies that were less able to attack the spike protein of the new UK variant.
Three patients, or 0.5%, had weakened antibody response to other parts of the variant, but Iwasaki said this might not be a significant problem because the patients were likely to have further antibodies that targeted loops and folds on the virus, and other immune defences that drew on T-cells to attack the pathogen.
The encouraging results come as cases of the new variant surge in the UK. The Office for National Statistics reported on Friday that it now accounts for more than 60% of positive tests in England and more than 80% in London. The sharp rise in infections has intensified calls for the vaccination programme to be rolled out as fast as possible.
“I believe it is important to give the first shots to as many people as possible, given the emergence of several more contagious variants on the rise,” said Iwasaki. “The second dose should be given, whenever they become available, as close to the recommended original schedule as possible, but a slight delay is not expected to significantly reduce the efficacy. People should wear masks and stay away from crowded indoor gatherings, even after getting the vaccines.”
Danny Altmann, a professor of immunology at Imperial College London who was not involved in the study, said it should comfort people who were worried that the new, more transmissible variants found in the UK and South Africa could be resistant to vaccines. He said the work suggested most people’s antibodies would still neutralise both variants.
Altmann said: “Many immunologists currently assume that the central, immunological interaction defining the ability to block virus entry is the generation of highly specific, neutralising antibodies that literally prevent virus infection of human cells. These antibodies are targeted to different shapes on the spike. An enormous endeavour over the past year has been to map these structures in great detail so that we may be able to design ever better blocking strategies.
“This new study from Winston Haynes and colleagues is a next, hitech step in this direction. Their very detailed datasets also offer comfort to those fearful that the new UK and South African variants may be able to evade the neutralising antibodies, diminishing effectiveness of the vaccines. The study reminds us that neutralisation encompasses a large array of
different antibody specificities at different sites, most of these unaffected by the mutations.”