Northwestern Medicine finds 3 versions of COVID-19 in Chicago

CHICAGO — Chicago has a unique version of the SARS-CoV-2 virus. Local researchers have made a discovery that could help direct future vaccines and treatments.

Viruses change as they travel. It’s their natural behavior and a trait scientists are tracking when it comes to SARS-CoV-2, the virus that causes COVID-19. Some of the changes are benign. Others are more critical when it comes to helping the virus spread and survive.

Northwestern Medicine researchers looked at samples from patients back in March. They found three different versions of the virus in circulation in Chicago.

One of those variants closely resembles the DNA sequence of samples found in China during the early days of the outbreak and hasn’t been found in many other areas of the United States. The two other versions are similar to viral sequences found in New York and on the West Coast, particularly in Washington state.

Dr Egon Ozer is with Northwestern Medicine and assistant professor of medicine in the division of infectious disease.

“Those that had the Chicago variant seem to have on average lower viral loads, less virus in their airways especially in the upper airways; the nose and throat,” Ozer said. “Compared to those viruses that were most closely related to New York strains. … And then in terms of vaccine development knowing where these differences are and knowing, especially if we see some variants are becoming more dominant, it could help us target our vaccine development a lot more, in a more focused matter.”

The researchers said there was no difference in patient outcomes or disease severity between the different mutations. And they said early signs point to the New York variant emerging as a more dominant strain.