Do Covid vaccines prevent you from spreading the virus, or do they just protect you from getting sick?
Scientists do not yet know this – and the uncertainty has major implications during the deployment of the vaccines.
Pfizer and Moderna, the companies that have developed the vaccines approved so far in the US, say their vaccines are about 95% effective in preventing people from getting sick with Covid symptoms. But there is still not enough evidence whether the vaccines also prevent asymptomatic infection and transmission.
According to the companies, there is still research to determine the answer. Without vaccines, research has suggested that asymptomatic transmission of the coronavirus caused by Covid is responsible for about a quarter of infections.
The experts believe the result is that precautions such as wearing masks, social removal and preventing overcrowded spaces will be needed until the country gets closer to herd immunity, the point at which enough people are immune to a disease to spread it. to make unlikely. Some studies have estimated that approximately 75% to 80% of the U.S. population must be immune to Covid-19 to achieve herd immunity, but this is a moving target and may increase as new variants emerge.