Four Major COVID-19 Variants: What You Should Know

Four Major COVID-19 Variants: What You Should Know

If there is one thing everyone can agree upon about SARS-CoV-2, the virus that causes COVID-19, is that it is constantly evolving. Since the start of the pandemic, we have seen four prominent variants, which include Alpha, Beta, Delta, and Omicron. The World Health Organization (WHO) names new coronavirus variants using the letters of the Greek alphabet, starting with the Alpha variant, which emerged in 2020. Here are some facts-in-brief about the different variants.


  • First appeared in Great Britain in November 2020 and infections surged in December of that year. It soon surfaced around the world and became the dominant variant in the U.S.

  • Eventually mutated into the B.1.1.7 lineage, which was 30 to 50% more contagious and was more likely to land infected people in the hospital and was deadlier than the original Alpha virus.

  • Vaccines developed by Pfizer, Moderna, and Johnson & Johnson showed potential in preventing severe disease and hospitalizations in Alpha cases. It eventually faded away with the rise of the more aggressive Delta variant.


  • Also known as B.1.351, was identified in South Africa at the end of 2020 and spread to other countries. However, Beta was not common in the U.S.

  • The CDC said Beta was about 50% more contagious than the original coronavirus strain, and evidence suggested that it may have been more likely than other variants to lead to hospitalization and death.

  • Pfizer-BioNTech, Moderna, and Johnson & Johnson reported that compared to Alpha, each of their vaccines were less effective against Beta.


  • First identified in India in late 2020; it soon spread throughout the world, becoming the dominant version of COVID-19—until Omicron took its place in mid-December 2021.

  • It is estimated that Delta caused more than twice the infections as previous variants, and more severe disease than other variants in people who were not vaccinated.

  • All three vaccines in the U.S. were considered highly effective against severe illness, hospitalizations, and death from Delta.

  • The CDC recommended “layered prevention strategies” regardless of one’s vaccination status. People were advised to practice such strategies as washing hands, wearing masks, and social distancing, especially indoors.

Omicron and it’s Subvariants

  • The first Omicron strain (BA.1) appeared in South Africa in late November 2021, and quickly spread to other countries. By December, Omicron was causing the number of cases daily in the U.S. to climb to over one million.

  • Omicron’s subvariants are highly contagious, with the BA.5 and BA.4 variants being better than other subvariants at evading protection provided by vaccines and previous infection.

  • Although Omicron was more transmissible than Delta, scientists are still trying to determine whether the BA.5 and BA.4 subvariants cause more severe disease than their predecessors.

  • The CDC says that while breakthrough infections in vaccinated people are expected, getting vaccinated and staying up to date with a booster shot is the best protection against Omicron.

This latest mutation of the Coronavirus is highly contagious, although the symptoms may be delayed or slightly less prevalent than previous strains.  By the time an afflicted person shows signs and symptoms of infection, they may have already passed it along to other people in their proximity.

Stay informed and proactive by getting tested regularly.