What the delta variant means for Americans this summer

The delta variant now makes up more than 26% of new COVID-19 cases in the U.S. and has been detected in all 50 states.

The delta variant now makes up more than 26% of new COVID-19 cases in the U.S. and has been detected in all 50 states, according to data from the Centers for Disease Control and Prevention. Just a month ago, the variant, which was first identified in India, made up just 3% of new cases in the U.S. In response to the worldwide threat posed by the variant, which is believed to be both more transmissible and more virulent than other strains, the World Health Organization shifted guidance, and now recommends that vaccinated individuals wear masks indoors. In the U.S., the CDC stayed the course, with health officials continuing to assert that fully vaccinated Americans do not need to wear masks inside. According to CDC Director Rochelle Walensky, the United States' strong vaccination rate and its use of highly effective vaccines enables it to do things differently. By comparison, much of the world is unvaccinated and evidence suggests that certain vaccines developed outside of the U.S. are less effective than Pfizer, Moderna and Johnson & Johnson.