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What are double and triple mutant variants? Why are they more dangerous?

This article was published on
May 6, 2021

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May 11, 2021: The World Health Organization named the B.1.617 - a "triple mutant variant" first found in India - a variant of concern. There is information suggesting this variant has increased transmissibility and may not respond to some of the immune system protections given by vaccines.

Double and triple "mutant" variants have two or three significant mutations among the many other mutations within their genetic codes. As of now, we do not know if these variants are more transmissible or dangerous but early data suggests they may spread more easily from person to person.

Double and triple "mutant" variants have two or three significant mutations among the many other mutations within their genetic codes. As of now, we do not know if these variants are more transmissible or dangerous but early data suggests they may spread more easily from person to person.

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What our experts say

As viruses spread, they change genetically. The longer a virus exists, the more genetic changes it may go through. Those changes, or "mutations," can help make a virus more or less dangerous, or even do nothing at all. Often the genes of a virus change in more than one way.

'Double mutant' and 'triple mutant' variants describe COVID-19 variants that have two or three key mutations that are also seen in other variants across the world. These double and triple mutations are significant because they are potentially linked with higher rates of transmission, so the virus may spread more easily and the variants may not be as sensitive to the body's efforts to fight them off.

It's important to note that double and triple mutant variants have not been listed as Variants of Concern and there is very limited data on transmission, symptoms, and vaccine responses for these variants. Whether or not they pose more danger to people infected with them has yet to be seen.

The key to stopping the rise of double and triple mutant variants is through widespread, rapid vaccination. The more people are protected against the spread of the virus, the less ability it has to reproduce and mutate among susceptible bodies. Wearing masks and socially distancing from others is another important way to stop the spread of COVID-19.

Context and background

Despite the scary names, double and triple mutant variants actually possess numerous mutations within themselves—which is normal, because the nature of viruses is to constantly replicate and mutate. As of now, it appears these variants may be more transmissible so they may spread more easily but not enough evidence has been generated to fully support this claim.

Resources

  1. People Are Talking About A 'Double Mutant' Variant In India. What Does That Mean? (National Public Radio)
  2. Transmission, infectivity, and neutralization of a spike L452R SARS-CoV-2 variant (Cell)
  3. SARS-CoV-2 Variant Classifications and Definitions (United States Centers for Disease Control and Prevention)
  4. Coronavirus: 'Double mutant' Covid variant found in India (BBC News)
  5. What Is The Triple Mutant Coronavirus Variant? What To Know About The Strain Found In India, Per Experts (Women's Health)
  6. Mutations, variants, strains? How are viruses classified? (POZ)
  7. What’s the difference between mutations, variants and strains? A guide to COVID terminology (The Conversation)
  8. WHO says India Covid variant of 'global concern' (BBC)

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