Viruses constantly change through mutation, and new variants of viruses are expected to occur. Multiple variants of the virus that causes COVID-19 have been documented, including a highly transmittable form of COVID-19 known as the delta variant.
The delta variant, which was first seen in December 2020 in India, is spreading globally. It's more contagious than the previous strains that have been detected in the U.S. It's also causing more severe illness.
Dr. Melanie Swift, co-chair of Mayo Clinic's COVID-19 Vaccine Allocation and Distribution Work Group, says now is the time to get vaccinated for COVID-19.
"We really need to take advantage of this time right now, when we have the vaccines that are freely available for everyone to get vaccinated so that we can stop the spread of the delta variant, but also so we can prevent the development of new variants," says Swift.
The Mayo Clinic News Network sat down with Swift, and she answered these questions about the delta variant.
Given the spread of the delta variant, why is vaccination for COVID-19 urgent now?
The situation with the delta variant can't really be overstated at this point. We are really at a pivotal moment in the pandemic right now. We were on the downtrend in the U.S., with increasing vaccination rates and decreasing cases. And what has happened is that we've gone from having our first case of the delta variant in the U.S. in March to it now being the vast majority of cases that have been sequenced.
The delta variant is more contagious than the previous strains that we've had in the U.S. But it's also causing more severe illness that is causing hospitalizations to increase and ICU admissions to increase. And we're looking at another wave of the pandemic. It's more contagious, and that's concerning. It's more serious, and that's concerning.
How effective are current vaccines against the delta variant?
The messenger RNA vaccines (Moderna and Pfizer) are highly effective against this variant. We have that information from clinical studies and from laboratory tests of what we think the immune response should be. They're showing clinically in the U.K., where the delta variant has been taking hold for many months now, that those messenger RNA vaccines are still highly effective — over 80% for infection and 90% or so for severe disease. So it's still very important to take those vaccines. The Johnson and Johnson vaccine is probably going to be very effective also.