In the early days of vaccine bliss, many Americans had thought that the shots were a ticket to normalcy—and at least for a while, that’s precisely what public-health experts were telling us: Sure, it was still possible for vaccinated people to get COVID-19, but you wouldn’t have to worry much about spreading it to anyone else. Interim guidance shared by the CDC in March stated that these cases “likely pose little risk of transmission,” and a few weeks later, CDC Director Rochelle Walensky said that “vaccinated people do not carry the virus.”
And then came Delta.
“The data are very clear that vaccinated individuals are less likely to spread the virus to others than unvaccinated individuals,” Christopher Byron Brooke, an assistant professor at the University of Illinois at Urbana-Champaign, told me in an email.
A recent paper Brooke co-wrote showed that vaccinated people shed less virus, stop shedding virus sooner than the unvaccinated, and shed particles that are less infectious—supporting the notion that they’re less likely to transmit disease.
One study from the Netherlands found a 63 percent reduction in household transmission among the vaccinated. That’s a testament to our vaccines.