just a heads
bloomberg.com
Covid Patients Show Key Immunity Gauge After Six Months in Study
Marthe Fourcade3 November 2020, 16:28 GMT+8
A crucial type of defensive blood cell persists for at least six months in people after Covid-19, even in those who had no symptoms, in a new study that may ease concern about waning immunity and its implications for a vaccine.
The research on 100 people shows that all had T-cell responses against a range of the coronavirus’s proteins, including the spike protein used as a marker in many vaccine studies, after half a year. Those who experienced symptoms had levels that were at least 50% higher than those who didn’t.
As a handful of vaccines nears the finish line, it’s still unclear how long any protection they afford would last. A small number of patients have fallen ill with Covid-19 twice.
“This is promising news,” said Fiona Watt, executive chair of the U.K.’s Medical Research Council. “If natural infection with the virus can elicit a robust T-cell response, then this may mean that a vaccine could do the same.”
A previous study, published last month by Imperial College London, raised concern that immune defenses may wane, as it showed that the percentage of Britons with antibodies declined over time.
Read more: Antibody Defense Against Covid Wanes Over Time, Study Suggests
T cells aren’t antibodies. They are white blood cells that can remember past diseases, kill virus-infected cells and rouse antibodies to marshal defenses when they are needed. People infected with another coronavirus that was responsible for the SARS epidemic in 2003, for example, still have a T-cell response to the disease 17 years later.
The study, from the a group of immunologists from 17 universities called the U.K. Coronavirus Immunology Consortium, has not yet been peer reviewed. It may be the first to show that a robust cellular memory against the virus persists for this long, the authors said.
None of the patients whose blood and serum samples were studied had been hospitalized with Covid-19.
Before it's here, it's on the Bloomberg Terminal.
LEARN MORE |
