Scientists have found evidence of protective immunity against Covid-19 in people up to four months after gentle or asymptomatic coronavirus infection, providing hope for the long-lasting efficacy of vaccines.
The researcher, including those from Queen Mary University of London analysed antibody and T cell responses in 136 healthcare workers in the United Kingdom, who had gentle or asymptomatic Covid-19 infection dating back to March.
The study, published in the publication Science Immunology, found that 89 per cent of healthcare workers analysed carried neutralising antibodies 16-18 weeks after infection.
The team, also involving researchers Imperial College London and University College London, UK, found most workers also had T cells capable of recognising more than one different parts of the virus.
Alternatively, they famous that the two responses did not at all times persist in concord, with some individuals showing T cell immunity but no evidence of antibodies, and vice versa.
“Our study of SARS-CoV-2 infection in healthcare workers from London hospitals reveals that four months after infection, around 90 per cent of individuals have antibodies that block the virus,” Joseph Gibbons, a Postdoctoral Research Assistant at Queen Mary, said.
“Even more encouragingly, in 66 per cent of healthcare workers we see levels of these protective antibodies are high and that this robust antibody response is complemented by T cells which we see reacting to more than a few parts of the virus,” Gibbons said.
Describing the finding as “good news”, he explained that whether someone has been infected with the coronavirus, there’s a good chance that they’re going to have developed antibodies and T cells that may supply some protection in case they encounter the virus again.
Much of the debate on protective immunity has focussed on the different roles of B cells, which make antibodies, and T cells, white blood cells which help offer protection to from viruses, including direct killing.
The most recent study found that while protective antibody responses were most often complemented by a T cell response, over half of the healthcare workers had different antibody and T cell responses.
The workers did not produce a T cell response particular to proteins found on the outer layer of the SARS-CoV-2 virus.
The research also found that T cell responses tended to be higher in those with the classic, defining symptoms of Covid-19, while asymptomatic infection resulted in a weaker T cell immunity than symptomatic infection, but equivalent neutralising antibody responses.
The new study also provides reassurance for vaccination efforts, suggesting that even following gentle infection, individuals carry antibody and T cell immunity to many parts of the virus, referred to as epitopes.
The researchers famous that while new variants are appearing, the changes to the virus don’t necessarily arise inside these epitopes so it is hoped the huge majority of immune recognition can likely continue unperturbed.
“Our study in asymptomatic and gentle cases gives a positive perception into the durability of immunity to SARS-CoV-2 after four months of infection,” Corinna Pade, a Postdoctoral Research Scientist at Queen Mary, said.
The researchers famous that it is crucial finding as gentle or even no symptoms of Covid-19 are very common and representative of most infections locally.
“Such abundant immune responses also give hope for the long-lasting efficacy of vaccines,” Pade added.
(This story has been published from a wire agency feed without modifications to the text.)
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