What are COVID Variants?

All viruses naturally evolve over time, and COVID-19 is no different. These new strains or variants may have unique characteristics, resulting in a change in severity or transmissibility.

Richard Martinello, MD, Medical Director of Infection Prevention answered some commonly asked questions about COVID-19 variants.

How many variants are there?

Around the world, there are about a dozen different variants tracked by the World Health Organization and Centers for Disease Control and Prevention. All of these variants are in Connecticut.

What is the Omicron variant? How does it differ from other variants?

The Omicron variant was first reported out of South Africa and has since spread quickly to several other countries. The WHO and CDC have classified it as a Variant of Concern due to its large number of mutations and it is now the dominant variant in Connecticut.

This variant spreads more easily than other variants and does not respond as well to monoclonal antibody treatment. The best protection against this variant remains vaccination including boosters.

What is the so-called “Stealth” variant?

A new sub-variant of Omicron called BA.2 is also in Connecticut. You may have heard this variant called the “stealth” variant in media reports because it can be hard to detect during testing and can appear similar to other variants. Currently there is no data to suggest this variant is more dangerous or spreads more easily that Omicron.

Should I wear a mask again?

Yale New Haven Health strongly recommends masks to help stop the spread of COVID-19 because they are highly effective in protecting yourself and others. Since the Omicron variant is more transmissible, pick a mask that has multiple layers of protection such as a KN95.

Does the vaccine protect against variants?

We are finding the COVID-19 vaccine and boosters to be highly effective, even against variants in protecting against severe infection and hospitalization. The majority of hospitalizations for COVID-19 are amongst people who did not get the vaccine. As more people are vaccinated, the better protected we will all be.

Learn more about the COVID-19 vaccine.