New guidance released by the federal Centers for Disease Control and Prevention on Tuesday advises vaccinated people in areas of “substantial” or “high” transmission — including almost the entirety of Missouri — to wear masks indoors.
All but two of the Show-Me State’s 114 counties are labeled by the agency as having substantial or high transmission levels, a result of lagging vaccination rates throughout the state and one of the most significant Delta variant outbreaks in the country. Almost two-thirds of U.S. counties fall into the substantial or high transmission categories.
The agency’s new recommendation is a reversal of previous guidance in May that fully vaccinated people could stop wearing masks outdoors in crowds and in most indoor settings. It comes as the more infectious Delta variant, the predominant strain driving infections in Missouri, continues to spread, with the potential of spreading from vaccinated individuals to unvaccinated ones, said CDC Director Dr. Rochelle Walensky.
Unvaccinated people should continue wearing masks until they are fully vaccinated.
Vaccinated people play a minimal role in transmission and “breakthrough” infections, in which a vaccinated person becomes sick with COVID-19, are rare. But early, unreleased data from the CDC suggests there is a possibility that the Delta variant produces higher level of virus in vaccinated people than previous strains, Walensky said, prompting the decision.
“The new science is worrisome and unfortunately warrants an update to our recommendations,” Walensky told reporters. “This is not a decision that the CDC has made lightly.”
Just under 41 percent of Missourians have been fully vaccinated, lagging behind the U.S. average of 49.75 percent, according to Johns Hopkins University data. Greene County and Christian County have vaccination rates even lower. As the guideline was issued, about 21 percent of the county’s population had been totally vaccinated.