Understanding viral variants

ORIGINALLY PUBLISHED
15 June 2021

Topic:

COVID-19

 


What are viral variants?

When a virus enters the body, it invades human cells and replicates (makes more copies of itself). When a virus makes copies of itself, it sometimes changes a bit. These changes are called mutations. A virus that has mutated is referred to as a variant.1

What impact can viral variants have?

Mutations and variants are very normal for any virus. All viruses change over time – including the virus that causes COVID-19.1 Most of the time, variants don’t impact how a virus works, or its ability to cause infection and disease.1 Sometimes however, variants can:

  • make the virus spread more easily
  • affect how well a person responds to treatment for the virus
  • impact testing for the virus and how well it is picked-up
  • reduce the effect of vaccines against the virus
  • cause more severe illness from the virus.

A variant of concern is the name given to any variant of the COVID-19 virus (SARS-CoV-2) that behaves in any of the above ways.2

Some variants can also have positive public health effects such as reducing a virus’s ability to spread. Variants can also disappear over time.


How can we protect against SARS-CoV-2 variants?

When a virus is circulating widely in a population, it will replicate more and the likelihood that variants will appear increases.1

The most effective way to stop more variants is to prevent the spread of COVID-19.1 Variants are seen more often when virus transmission levels are high, so we need to bring these levels down.

Measures to reduce virus transmission continue to work and will also help to curb the number of future variants, including handwashing, good ventilation, physical distancing, mask wearing and preventative treatments, such as vaccines.1

According to the World Health Organization (WHO), rolling out vaccines as quickly and widely as possible is also critical to protect people from the virus and the risk of new variants.1

What do we know about SARS-CoV-2 virus variants that cause        COVID-19?

The World Health Organization, in collaboration with national authorities, expert networks and researchers, has been monitoring and assessing the emergence of SARS-CoV-2 variants around the world. Latest information on the tracking of SARS-CoV-2 variants, including SARS-CoV-2 variants of concern, can be found on the World Health Organization website.2

Can vaccines protect against COVID-19 variants?

The current vaccines for COVID-19 were designed to give broad protection against the virus and offer some level of protection against different variants.1

In time, it is thought different vaccine tactics may be needed as new variants arise. This might include changing the vaccine dose, additional booster vaccinations, combination vaccines or adapting the vaccines themselves to target variants.1



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References

1. The effect of virus variants on COVID-19 vaccines. Available at http://www.who.int/news-room/feature-stories/detail/the-effects-of-virus-variants-on-covid-19-vaccines. Last accessed June 2022.

2. Tracking SARS-CoV-2 variants. Available at http://www.who.int/en/activities/tracking-SARS-CoV-2-variants/. Last accessed June 2022.

Veeva ID: Z4-43671
Date of preparation: June 2022