70% of fully vaccinated prisoners caught COVID-19 in a Texas Delta outbreak, the CDC says - but vaccines protected against severe disease

• About 70% of fully vaccinated people in a Texas prison caught COVID-19 in an outbreak, the CDC said.
• The data suggests that while Delta can spread among vaccinated people, vaccines protect against severe COVID-19.
• Of the unvaccinated prisoners, 93% caught COVID-19, and one died, the CDC said.

More than two-thirds of fully vaccinated people in a Texas prison caught COVID-19 during an outbreak of the Delta variant in July, but vaccines protected against severe illness, a study from the Centers for Disease Control and Prevention found.

Of 185 fully vaccinated prisoners at the unnamed prison, 129, or about 70%, caught the virus, data compiled by the CDC and the Federal Bureau of Prisons showed. This was a much lower rate than the unvaccinated prisoners, 39 of 42 of whom - or about 93% - caught COVID-19 during the outbreak, said the study, published Tuesday in the CDC's Morbidity and Mortality Weekly Report.

Four people, three of whom were unvaccinated, needed treatment in a hospital, the study said. One unvaccinated person died, it said.

Most of the prisoners were white men, and many had received Pfizer's vaccine at least four months before the outbreak, the data showed.

The study adds to growing evidence that COVID-19 vaccines cut the risk of severe disease and hospitalization. Prisons tend to have higher rates of COVID-19 and deaths because of cramped living conditions and underlying health conditions, the CDC said.

Another CDC study from this month found that unvaccinated Americans were 11 times as likely to die of COVID-19 as vaccinated people. About 45% of people in the US are unvaccinated, according to the CDC.

The latest CDC study showed that the Delta variant can spread among both vaccinated and unvaccinated people. "Infectious virus was cultured from vaccinated and unvaccinated infected persons," the study said.

Measures like masks and regular testing are "critical" where physical distancing is "challenging," even if vaccination rates are high, the CDC said.