Understanding COVID-19 Variants

Published: July 26, 2021
Barbara Young
By Barbara Young, Pharm.D.

COVID-19 is an acute respiratory condition that was first recognized in December of 2019 in China. 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 they 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 four variants defined by the location (country), scientific name, and Greek letter.

These are the four 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 detected in the United Kingdom and first found in the U.S. in December 2020.



This variant was initially detected in South Africa in December 2020 and first found in the U.S. at the end of January 2021.



This variant was initially identified in travelers from Brazil, who were tested during routine screening at an airport in Japan, in early January 2021. It was first found in the U.S. in January 2021.



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


Other variants, such as Epsilon (B.1.427 and B.1.429; found in California), Lambda (C.37; found in Peru), and Iota (B.1.526; found in United States), are being tracked as “variants of interest” by the Centers for Disease Control (CDC) to monitor the extent of the variant in the U.S and evaluate any significant changes in disease severity.

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.

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.

Emerging data from the United Kingdom shows that Delta variant symptoms are associated more with cold symptoms such as sneezing, runny nose, headache, coughing, and sore throat as compared with symptoms like fever, cough, shortness of breath, and loss of taste that were reported for previous variants.

The CDC recommends that you should be tested if you have any symptoms associated with a COVID-19 infection. To find a testing site near you, click here.

Does the COVID-19 vaccine protect against the variants?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.

Starting September 20, 2021, booster doses of the Pfizer-BioNech and Moderna COVID-19 vaccines are to be given 8 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 not yet recommended for the Janssen/Johnson & Johnson COVID-19 vaccine.

How can I protect myself from variants?
You can take important actions to decrease the spread of COVID-19 infection by getting vaccinated, 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. 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.

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