study authors say protection against symptomatic infection began to appear in phase three of the vaccine's clinical trial.AdvertisementResearchers said this study's data suggests the risk of asymptomatic COVID-19 infection decreased by four times among participants who got their vaccine at least 12 days ago.
Researchers said they found the vaccine had an "intermediate effect" on asymptomatic infections within the first 12 days. In general, if vaccination doesn’t completely prevent infection, it will significantly reduce the amount of virus coming out of your nose and mouth – a process called shedding – and shorten the time that you shed the virus.