• How quickly does COVID immunity fade? What scientists know
    https://www.nature.com/articles/d41586-023-00124-y

    New evidence suggests that ‘hybrid’ immunity, the result of both #vaccination and a bout of #COVID-19, can provide partial protection against #reinfection for at least eight months1. It also offers greater than 95% protection against severe disease or hospitalization for between six months and a year after an infection or vaccination, according to estimates from a meta-analysis2. Immunity acquired by booster vaccination alone seems to fade somewhat faster.

    But the durability of immunity is much more complex than the numbers suggest. How long the immune system can fend off #SARS-CoV-2 infection depends not only on how much immunity wanes over time but also on how well immune cells recognize their target. “And that has more to do with the virus and how much it mutates,” says Deepta Bhattacharya, an immunologist at the University of Arizona College of Medicine in Tucson. If a new #variant finds ways to escape the existing immune response, then even a recent infection might not guarantee protection.

    […]

    Thålin understands how frustrating the caveats and uncertainty can be, but says that researchers aren’t likely to pin down an answer anytime soon. “The virus is evolving so fast,” she says. “What’s true today might not be true tomorrow.”

    #immunité