In the U.S., we’ve seen three predominant strains of COVID-19. Dr. Marc Johnson from Atrium Health shares more about the most recent Delta variant.

Coronavirus Updates, Your Health | one year ago

What You Should Know About the COVID-19 Delta Variant

In the U.S., we’ve seen three predominant strains of COVID-19. Dr. Marc Johnson from Atrium Health shares more about the most recent Delta variant.

Since the beginning of the COVID-19 pandemic, multiple variants of the virus have emerged. All viruses mutate (or change) over time, and COVID-19 is no exception. When a mutation changes how the virus behaves – for example, making it more contagious – the new version is known as a variant or strain.

While we originally saw the Wuhan strain in the United States, we have also seen the Alpha strain and are now experiencing an influx of Delta strain cases. To learn more about the recent Delta variant, we spoke with Marc Johnson, MD, professor of medicine in the Department of Infectious Disease at Atrium Health, to share how this strain may affect you and your community.

The Delta Variant Appears to be More Contagious

According to Dr. Johnson, the COVID-19 Delta variant originated in India. Since spreading to the U.S., this strain is now present in all 50 states and accounts for most of all COVID-19 hospitalizations to date.

“The Alpha variant was the predominant strain last year, which was 50% more infectious than the Wuhan strain. Now, Delta is proving to be around 50% more infectious than Alpha, so it is definitely something to be concerned about,” Dr. Johnson says. “In fact, because of the Delta variant, COVID-19 cases are no longer falling. Delta is rapidly spreading and appears to be more contagious and more severe than earlier versions of the virus.”

Studies show that the Delta variant causes a hospitalization rate two times higher than other strains of COVID-19. This suggests that Delta may be more pathogenic, or can more easily latch onto lung cells and cause more virus symptoms and damage than the previous Alpha strain.

While more research is needed to determine the efficacy of the approved COVID-19 vaccines against the Delta variant, current data suggests that breakthrough cases, or infections among people who are fully vaccinated, are possible but rare. Unvaccinated individuals remain most at risk. According to the U.S. Centers for Disease Control and Prevention, more than 95% of nationwide COVID-19 deaths in June were in unvaccinated people.

“While individuals who have been vaccinated can still be infected with the Delta variant of COVID-19, most experience mild symptoms and do not have a severe reaction,” says Dr. Johnson. “However, unvaccinated populations and children under 12 should be most concerned with this new variant. Because of the high transmission of this variant, we expect to see erratic pockets of COVID-19 surges in areas where a large percentage of the population remains unvaccinated.”

Experts say the best way to protect yourself from the Delta variant, including severe illness, hospitalization and death, is to get the COVID-19 vaccine. The FDA has authorized three vaccines that are deemed safe, effective and protective against COVID-19.

To schedule an appointment to receive a COVID-19 vaccine, or to find a walk-in vaccine event near you with no appointment needed, visit