we’ll probably need coronavirus booster shots. But which one Scientists know that vaccine-induced immunity against most diseases wanes, but the answers to those questions about the coronavirus will begin to coalesce only in the coming weeks and months.
First, scientists need to identify a threshold — what level of immunity is too low to protect people? Then, they need to learn how long it typically takes for immunity to decay to that level. And then they need to figure out how to best boost people’s immunity.
· In the next month, Beigel expects results from studies of people who got sick despite being vaccinated in clinical trials, findings that could help establish an immunity baseline — what scientists call a “correlate of protection.” Those studies could help researchers establish a threshold — such as a minimum antibody level — that signals whether someone is immune or whether that person has become vulnerable to infection.
· Scientists are analyzing blood samples from the first people who were vaccinated a year ago in trials, hoping to determine whether antibodies continue to stick around or if they vanish. Earlier research found that the disease fighters remain at robust levels for at least six months following Moderna vaccination, although variants can complicate that, with antibody protection that fades faster. A recent Nature study found that antibodies do decline after people recover from infection, but they don’t keep plummeting — they plateau and persist nearly a year later.
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