What's the concern about the new COVID-19 variants? Are they more contagious?
Answer From Daniel C. DeSimone, M.D.
Viruses constantly change through mutation. When a virus has one or more new mutations it’s called a variant of the original virus. Currently, the Centers for Disease Control and Prevention (CDC) has identified one variant of the virus (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) as a variant of concern:
- Omicron. This variant spreads more easily than the original virus that causes COVID-19 and the delta variant. However, omicron appears to cause less severe disease. People who are fully vaccinated can get breakthrough infections and spread the virus to others. But the COVID-19 vaccines are effective at preventing severe illness. This variant also reduces the effectiveness of some monoclonal antibody treatments. Omicron has a few major offshoots (sublineages), including BA.5 and BA.2.12.1. BA.5 made up about 88% of COVID-19 infections that had genetic sequencing in the U.S. in August, 2022, according to the CDC.
In April, the CDC downgraded the delta variant from a variant of concern to a variant being monitored. This means that the delta variant isn’t currently considered a major public health threat in the U.S.
To strengthen protection against COVID-19 and circulating variants, the CDC recommends staying up to date with your COVID-19 vaccines and any additional primary shots and boosters for which you are eligible.
Aug. 27, 2022
Daniel C. DeSimone, M.D.
See more Expert Answers
- COVID data tracker: Variant proportions. Centers for Disease Control and Prevention. https://covid.cdc.gov/covid-data-tracker/#variant-proportions. Accessed Aug. 23, 2022.
- What you need to know about variants. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/variants/variant.html. Accessed Feb. 16, 2021.
- Tracking SARS-CoV-2 variants. World Health Organization. https://www.who.int/en/activities/tracking-SARS-CoV-2-variants/. Accessed Nov. 29, 2021.
- SARS-CoV-2 variant classifications and definitions. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/variant-surveillance/variant-info.html#Concern. Accessed July 7, 2022.
- Update on omicron. World Health Organization. https://www.who.int/news/item/28-11-2021-update-on-omicron. Accessed Nov. 29, 2021.
- Science brief: Omicron (B.1.1.529) variant. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/scientific-brief-omicron-variant.html. Accessed Jan. 3, 2021.
- Statement on Omicron sublineage BA.2. World Health Organization. https://www.who.int/news/item/22-02-2022-statement-on-omicron-sublineage-ba.2. Accessed March 25, 2022.
- Neutralization of the SARS-CoV-2 omicron BA.1 and BA.2 variants. The New England Journal of Medicine. 2022; doi: 10.1056/NEJMc2201849.
- Stay up to date with your vaccines. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/stay-up-to-date.html. Accessed July 7, 2022.