RIO DE JANEIRO, BRAZIL - As some vaccines near the finish line in the race for an immunizer, it is still unclear how long the protection offered could last.
A crucial type of defensive blood cell persists for at least six months in people who have been cured of Covid-19, even for those who had no symptoms. This is indicated by a new study that may lessen the concern over immunity and its implications for a vaccine.
The study, conducted with 100 subjects, shows that all had T-cell responses against a range of coronavirus proteins, including the spike protein . . .