But that is only the beginning of what people have had to absorb. Research shows the delta variant is not only twice as transmissible as the original strain of the virus, it may cause more severe disease. Drug companies and the government are investigating whether efficacy of the vaccines wanes over time and whether some people, including the immunocompromised and health workers, will need a booster shot. Vaccinated people can transmit the virus. The Centers for Disease Control and Prevention again changed its recommendation on mask-wearing.

Source: Washington Post August 10, 2021 11:02 UTC