Washington (AFP) – Test monkeys infected with the new coronavirus responsible for the COVID-19 pandemic were protected from reinfection until 28 days later, a Chinese study said Thursday in the journal Science.
Although the monkeys showed initial immunity, it is unclear how long such immunity will last in humans: it will take months or even years to know if the millions of people infected at the start of the pandemic are protected against reinfection. .
Scientists at the Peking Union School of Medicine conducted an experiment with rhesus macaques, often used for their similarities to humans, to determine if they have short-term immunity to the virus.
Six rhesus macaques were infected in their windpipe with a dose of the SARS-CoV-2 virus. They developed mild to moderate symptoms and took about two weeks to recover.
Twenty-eight days after the first infection, four of the six monkeys received another dose of the virus, but this time, despite a brief rise in temperature, they showed no signs of reinfection, the study authors wrote.
By taking frequent samples, the researchers found that the maximum viral load was reached three days after the monkey’s infection.
The monkeys showed a stronger immune response after the first infection, producing more so-called neutralizing antibodies that may have protected them from reinfection in the short term, the scientists wrote.
More experiments are needed to see how long this immune defense remains, the authors said.
