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What is the Delta Variant and Do Vaccines Help?

COVID-19 is constantly changing. These variants require research and assessment. And now, the latest variant, Delta, is here. Joe Gastaldo, MD, System Medical Director of Infectious Diseases at OhioHealth tells us it was first identified in India. A few weeks ago, it was about 6% of the circulating strains in the United States. Every 10 to 14 days that doubles and approximately now we are seeing it in about 15 to 20% of all circulating strains. People who have the Delta variant are more contagious. It’s 40 to 70% more transmissible. We do not know yet if the Delta variant is associated with a higher severity of illness, but moving forward for those who have not been vaccinated, it’s going to be a riskier for them if they contract COVID-19.

Watch the video below to hear what Dr. Gastaldo has to say about the variant and our current vaccines.

A common question Dr. Gastaldo gets is how effective are our current vaccines against the Delta variant. This has been studied and based on lab in vitro studies, it appears that two doses of the mRNA vaccines by Pfizer and Moderna provide approximately 90% effectiveness against the Delta variant. We do not yet have that information for the Johnson & Johnson vaccine. That’s to be determined. The point is, single dose mRNA vaccines and the single dose AstraZeneca vaccine – which is not yet available in this country – are considered really sub optimal for the Delta variant. If you are fully vaccinated with the Pfizer Moderna vaccine, you have a wonderful layer of protection against the Delta variant.

Want to learn more about common COVID-19 questions? Check out our Fast Facts page.


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