That's because vaccinated people have already made antibodies to the coronavirus. Even if those antibodies don't prevent infection, they still "should be coating that virus with antibody and therefore helping prevent excessive downstream transmission," Kedl says. And a virus coated with antibodies won't be as infectious as a virus not coated in antibodies.
Breakthrough infections might not be a big transmission risk. Here's the evidence
Are vaccinated people who get COVID as likely to spread the infection as unvaccinated people? Scientists don't think so.
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