Experts say studying those who have not yet caught Covid has become just as critical as studying those who have.
More than half of Americans may have never had Covid, according to U.S. government data, leaving scientists wondering whether those who’ve avoided the novel coronavirus might actually be immune to the virus altogether. This could offer new clues into how to attack Covid. At this stage in the pandemic, people may be immune due to vaccines, a past infection, or a combination of both. There’s also evidence that, in rare instances, some people may be Covid-immune without infection or vaccination at all. The coronavirus’s frequent mutations and the fact that immunity wanes over time make it difficult to discern how many people are immune at any given moment. Studies have shown, for example, that while omicron infections offer some immunity against delta, omicron is able to circumvent antibodies from both past infection with other variants and vaccination. Current surveillance techniques have also likely vastly underestimated the number of cases, as more people are taking Covid tests at home and not reporting the results.