More than 70 people involved with the Tokyo Olympics have tested positive for COVID-19, including some United States athletes.
American beach volleyball player Taylor Crabb is the latest Olympic athlete to test positive. Kara Eaker, an alternate on the U.S. gymnastics team, also tested positive, along with basketball player Katie Lou Samuelson. Eaker and Samuelson confirm they are fully vaccinated.
"In Japan where there's increasing number of cases in the community every week in the country, one can imagine that vaccinated people are not immune to breakthrough cases," UCSF infectious disease specialist Dr. Peter Chin-Hong said.
Once athletes arrive at the Olympic Village, they are tested for COVID-19 every morning using a saliva test.
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Chin-Hong said screenings are not foolproof.
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"There are limits in testing," he said. "It takes probably from exposure to the time when the test turns positive anywhere from four days or so onwards for it to be a positive test after exposure. Before then, you can definitely have false negative testing."
But he said if a sample is collected appropriately, then the saliva PCR test used at the Olympics has been shown to be accurate.
About 11,000 athletes are scheduled to compete in the Tokyo Olympics. They are not required to be vaccinated.