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Solving COVID

Large COVID-19 study from Iceland has good news on enduring antibody protection, vaccine prospects

A study of more than 30,000 people in Iceland found that antibodies produced after a COVID-19 infection last for at least four months, researchers reported Tuesday in the New England Journal of Medicine. Previous studies have suggested antibody protection wears off quickly, but most of those studies examined coronavirus infections 28 days after diagnosis. This new study, conducted by deCODE Genetics, found that a second wave of antibodies forms and grows steadily during the first two months after infection, then plateaus for at least two more months.

Evidence that people produce enduring antibodies from a natural infection is promising news for vaccine researchers, working to spark that immunity through inoculation. This large-scale study "focused on a homogeneous population largely from a single ethnic origin and geographic region," and results may vary elsewhere, scientists from Harvard University and the National Institutes of Health wrote in a commentary accompanying the report. "That said, this study provides hope that host immunity to this unpredictable and highly contagious virus may not be fleeting and may be similar to that elicited by most other viral infections."

Iceland has tested about 15 percent of its population for COVID-19 since February, creating an unusually rich data set. The researchers also report that women, older patients, people with more severe cases of COVDI-19, and nonsmokers had higher levels of antibodies; that nearly a third of people infected reported having no symptoms; and that the new virus killed about 0.3 percent of everyone infected, about three times the rate of the seasonal flu.