This document contains guidance and answers to frequently asked questions (FAQs) for Penn Medicine providers and staff in regards to the coronavirus disease 2019 (COVID-19) variant known as Delta and the use of a third booster vaccination. From the Overview: "The dominant strain of COVID-19 in the United States is now the Delta variant:  The Delta variant is highly contagious, more than 2x contagious as previous variants.  Some data suggest that the Delta variant might cause more severe illness than previous strains in unvaccinated persons.  Unvaccinated people remain the greatest concern. Although breakthrough infections happen much less often than infections in unvaccinated people, individuals infected with the Delta variant, including fully vaccinated people with symptomatic breakthrough infections, can transmit it to others.  Fully vaccinated people with Delta variant breakthrough infections can spread the virus to others. However, vaccinated people appear to be infectious for a shorter period. Previous variants typically produced less virus in the body of infected fully vaccinated people (breakthrough infections) than in unvaccinated people. In contrast, the Delta variant seems to produce the same high amount of virus in both unvaccinated and fully vaccinated people."
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