Outbreak of SARS-CoV-2 B.1.617.2 (Delta) Variant Infections Among Incarcerated Persons in a Federal Prison — Texas, July–August 2021

Early Release / September 21, 2021

What is added by this report?


During a COVID-19 outbreak involving the Delta variant in a highly vaccinated incarcerated population, transmission rates were high, even among vaccinated persons. Although attack rates, hospitalizations, and deaths were higher among unvaccinated than among vaccinated persons, duration of positive serial test results was similar for both groups...

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During July 2021, a COVID-19 outbreak involving the Delta variant was identified in a federal prison in Texas, infecting...74%...incarcerated persons in two housing units...The attack rate was higher among unvaccinated versus fully vaccinated persons 93% versus 70%. Four persons were hospitalized, three of whom were unvaccinated, and one person died, who was unvaccinated.

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Attack rates...among persons vaccinated ≥4 months before the outbreak...89%) than among those vaccinated 2 weeks to 2 months before the outbreak 61%.

So in this case vaccine efficacy waned over 4 months to such extent that the vaccinated were infected (89%) nearly as fully as the unvaxed (93%).