Coronavirus immunity ‘probably significantly higher’ than tests suggested
Tuesday, 30 June 2020
Public immunity to the new coronavirus could be higher than antibody suggest, according to research from Karolinska Institutet and Karolinska University Hospital in Sweden.
People who have not tested positive for antibodies – which neutralise the disease – for the new coronavirus (Covid-19) can still show what’s known as T-cell-mediated immunity to the virus. “T cells are a type of white blood cells that are specialised in recognising virus-infected cells,” explained Marcus Buggert, assistant professor at Karolinska Institutet’s Centre for Infectious Medicine.
“Advanced analyses have now enabled us to map in detail the T-cell response during and after a Covid-19 infection,” Buggert said. “Our results indicate that roughly twice as many people have developed T-cell immunity compared with those who we can detect antibodies in.”
“One interesting observation was that it wasn’t just individuals with verified Covid-19 who showed T-cell immunity but also many of their exposed asymptomatic family members,” said Soo Aleman, who has been monitoring and testing coronavirus patients and their families.
“Moreover, roughly 30% of the blood donors who’d given blood in May 2020” (who were included in the control group in the study) “had Covid-19-specific T cells, a figure that’s much higher than previous antibody tests have shown,” she added. The levels of the T-cells are as high as you would find in someone who has been vaccinated.“
Our results indicate that public immunity to Covid-19 is probably significantly higher than antibody tests have suggested,” commented Professor Hans-Gustaf Ljunggren. “If this is the case, it is of course very good news from a public health perspective.”
“Larger and more longitudinal studies must now be done on both T cells and antibodies to understand how long-lasting the immunity is and how these different components of Covid-19 immunity are related,” Buggert said.