People still have a detectable immune response six months after being infected with COVID-19, according to the first study of its kind.
The UK study found that people who had previously developed COVID-19 had raised levels of T-cells, an important back-up to antibodies in fighting infections.
But the researchers, from Public Health England and the UK Coronavirus Immunity Consortium, warn that it’s still not clear whether the T-cell levels were high enough to protect against re-infection.
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Professor Paul Moss of the University of Birmingham, who led the Consortium, said the findings were “encouraging”, but important questions remain.
“It’s reassuring that evidence of immunity remains after this time,” he said.
“But one can’t translate this into protective immunity passports in any way. It does not mean these people are protected.”
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Further large-scale studies are underway to confirm whether T-cells can prevent re-infection.
The researchers took blood every month from 100 people who had confirmed COVID-19 in March and April.
Six months on, all of them had CD4 and CD8 T-cells, which kill body cells that have been infected by a virus and rally the rest of the immune system to mount a fight-back.
The study, which has yet to be peer-reviewed, also found those who had coronavirus symptoms in the spring had T-cell levels 50% higher than those who were asymptomatic.
But the research doesn’t settle the debate over herd immunity.
Source: Sky News