What We Know About Delta Variant

What We Know About Delta Variant

Sun Staff Reports

The Center for Disease Control (CDC) recently released updated guidance on the need for urgently increasing COVID-19 vaccination coverage and a recommendation for everyone in areas of substantial or high transmission to wear a mask in public indoor places, even if they are fully vaccinated. CDC issued this new guidance due to several concerning developments and newly emerging data signals.

First is a reversal in the down¬ward trajectory of cases. In the days leading up to our guidance update, CDC saw a rapid and alarming rise in the COVID case and hospitalization rates around the country.

In late June, our seven-day moving average of reported cases was around 12,000. On July 27, the seven-day moving average of cases reached over 60,000. This case rate looked more like the rate of cases we had seen before the vaccine was widely available.

Second, new data began to emerge that the Delta variant was more infectious and was leading to increased transmissibility when compared to other variants, even in vaccinated individuals. This includes recently published data from CDC and our public health partners, unpublished surveillance data that will be publicly available in the coming weeks, information included in CDC’s updated Science Brief on COVID-19 Vaccines and Vaccination, and ongoing outbreak investigations linked to the Delta variant.

The Delta variant is currently the predominant strain of the virus in the United States. Below is a high-level summary of what CDC scientists have recently learned about the Delta variant. More information will be made available when more data is published or released in other formats.

Infections and Spread

The Delta variant causes more infections and spreads faster than early forms of SARS-CoV-2

The Delta variant is more contagious than previous strains — it may cause more than two times as many infections. Vaccines protect you.