Understanding COVID-19 Variants

Published: December 16, 2021
Barbara Young
By Barbara Young, PharmD

COVID-19 is an acute respiratory condition that was first recognized in December of 2019 in China and then spread worldwide. It is caused by a coronavirus called SARS-CoV-2. As the COVID-19 pandemic continues, certain mutations, or variants, of the coronavirus have emerged.

What are COVID-19 variants?What is a variant?
Variants are viruses that differ by one or more changes in their genetic sequence called a mutation. These changes are caused as the viruses move from person to person. Often these changes have little or no impact on the virus. However, in some cases, the variant may become more contagious or more deadly than the original virus.  

Why do variants occur?
All viruses change over time. This is one of the reasons why you get a flu shot every fall—the shot is tailored to be effective against specific strains or variants of the flu. Variants may begin in a specific area or country, but then can be transferred by person-to-person contact and travel, particularly in unvaccinated individuals. The more the virus spreads, the more likely they are to change, and the more likely that a variant will occur.

How are COVID-19 variants named?
Initially, the COVID-19 variants were identified with a name based on the country where the changes were first noted and a scientific name. Later the World Health Organization assigned a letter from the Greek alphabet to provide an easier way to identify the variants. For instance, here are variants defined by the location (country), scientific name, and Greek letter.

These are the two variants currently circulating in the United States that are considered a “variant of concern,” meaning federal agencies are closely monitoring and characterizing them.

Scientific name

Greek letter

Country of origin



This variant was initially identified in India in December 2020 and first found in the U.S. in March 2021.

 B.1.1.529 Omicron Multiple countries, November 2021

Other variants are tracked as “variants of interest” by the Centers for Disease Control (CDC) to monitor the spread of the variant in the U.S and evaluate any significant changes in disease severity, response to the vaccine, or medications used to treat the virus. Here is a link to the current variants being tracked by the CDC: https://www.cdc.gov/coronavirus/2019-ncov/variants/variant-info.html.

Should I be worried about the COVID-19 variants?
There are a number of concerns about the COVID-19 virus variants. In many cases, research shows that some variants can spread more easily from person-to-person and have the ability to cause an increase in the severity or type of symptoms. When a virus variant is more contagious and causes more severe illness, it may lead to more hospitalizations and deaths.

Does the COVID-19 vaccine protect against the variants?For example, as the Delta variant became the most common variant in the U.S., the number of cases increased, particularly in unvaccinated individuals, due to increased spread in communities like yours. The Omicron variant is currently being tracked to determine how easily it spreads to vaccinated and unvaccinated people, to evaluate severity of the infections, and to see this new variant becomes more prominent than the Delta variant.

The CDC recommends that you should be tested, even if you are vaccinated, if you have any symptoms associated with a COVID-19 infection such as runny nose, headache, sneezing, sore or scratchy throat, and persistent cough as well as loss of taste, fever, and shortness of breath or trouble breathing. To find a testing site near you, click here.

Does the COVID-19 vaccine protect against the variants?
Vaccines have been shown to provide protection against COVID-19 infection, and to date, the vaccines are effective against the variants. Importantly, the vaccines continue to prevent severe disease, hospitalizations, and death from COVID-19 even with the presence of variants. However, recent information has shown that the variants are decreasing vaccine efficacy in preventing infection from COVID-19 because the vaccine doesn’t recognize the original parts of the virus that it was designed to provide immunity against.

The CDC and the FDA now recommend booster doses of the Pfizer-BioNtech and Moderna COVID-19 vaccines to be given 6 months after completing the first 2-dose series of vaccines. This additional dose “boosts” the immune system to create antibodies to COVID-19 and extends the vaccine’s protection. Boosters are also recommended for the Janssen/Johnson & Johnson COVID-19 vaccine 2 months after receiving the first injection. People can receive a booster dose of any COVID-19 vaccine authorized for use in the U.S. The booster does not need to match the vaccine product received in the initial dose(s).

How can I protect myself from variants?
You can take important actions to decrease the spread of COVID-19 infection by getting vaccinated (including a booster dose), wearing a mask when and as instructed, practicing physical distancing, avoiding poorly ventilated spaces, and washing hands. Also, it is important to get tested if you have symptoms of COVID-19 infection.

Vaccines have been shown to provide protection against COVID-19 infection. The CDC and other healthcare organizations recommend getting a COVID-19 vaccine, including a booster dose at the appropriate time. Vaccination reduces your risk of getting severe complications and spreading the virus. Vaccination has also been found to be effective against the current variants.


NOTE:  The information contained in this article is rapidly evolving because of ongoing research. Talk to your pharmacist or other health care provider if you have any questions about your medications, COVID-19, or other health issues.

Related Articles

subscribe section background