All three authorized vaccines in the United States offer recipients robust protection against illness, particularly the worst cases. But how good are they at blocking transmission to other people?
Because that question has no definitive answer, fully vaccinated people are advised to still wear their masks in public. The future contours of the pandemic and the risk posed by variants remain blurry without understanding whether the virus will keep circulating even once most people are vaccinated.
[Virologist Larry Corey] considered college students an ideal population to study transmission. They were young, living in dormitories with many social contacts, had high attack rates from the virus and were likely to have mild or asymptomatic infections.
Students in [a new 20-college] study will swab their noses daily, providing a wealth of information.
Scientists will learn about the duration of infections in vaccinated and unvaccinated people and measure how much virus they have in their noses and for how long. Researchers will learn the real-world consequences of carrying different amounts of virus by repeated testing of the vaccinated participants’ close contacts. The genetic fingerprints of virus samples will be taken, giving insight into how the shots work against variants.
The study could provide crucial knowledge about the ability of people with asymptomatic infections to spread the virus.