People who suffer mild Covid-19 symptoms may carry protective antibodies for only a matter of weeks, potentially complicating the search for a vaccine, a study suggests.
Researchers in Spain who screened nearly 70,000 people found that 14 per cent who were positive for antibodies in a first round of testing gave a negative result two months later. The apparent disappearance of antibodies was mostly seen in those who had very mild symptoms or who had been asymptomatic.
“Immunity can be incomplete, it can be transitory, it can last for just a short time and then disappear,” Raquel Yotti, director of Spain’s Carlos III Health Institute, which co-led the study, said. “We must keep protecting ourselves and protecting others.”
Other researchers said that the findings appeared
