CDC to show vaccinated people infected with Delta remain contagious

The Centers for Disease Control and Prevention is expected to announce in early August that new data shows people vaccinated against COVID-19 who become infected with the Delta variant can spread it and infect others, the New York Times reported on July 29.

The revelation is one reason the agency reversed course this week and said fully vaccinated people should go back to wearing masks in many cases.

The new findings also are a reversal from what scientists had believed to be true about other variants of the virus, the New York Times said. The bottom line is that the CDC data shows people with so-called breakthrough cases of the Delta variant may be just as contagious as unvaccinated people, even if they do not show symptoms.

ABC News reported earlier on Jul 29 that the CDC’s updated mask guidance followed an outbreak on Cape Cod, where crowds gathered for the Fourth of July.

As of July 29, 882 people were tied to the outbreak centered in Provincetown, Mass. Of those who live in Massachusetts, 74% were unvaccinated. ABC said the majority were showing symptoms of COVID-19.

A version of this article first appeared on Medscape.com.