What you need to know about the Delta variant

Learn how to keep yourself and your family safe from the Delta variant of COVID-19.

By UNICEF
Health worker Pravinsinh S Baria stands as he awaits a case to be assigned in Godhra in Godhra, Gujarat, India.
UNICEF/UN0498316/Reddy
23 September 2021

People around the world are concerned about the highly-contagious Delta variant of COVID-19. We’ve gathered the latest expert information to answer some of the most common questions about this new variant and will continue to update this article as more information becomes available.

For more tips and information on COVID-19, see our COVID-19 guide for parents

What is the Delta variant? 

The Delta variant of COVID-19 has been called a variant of concern by WHO because of its increased transmissibility and increased ability to cause a severe form of the disease. Where the Delta variant is identified, it quickly and efficiently spreads between people.  

How did the Delta variant come about?

When a virus is circulating widely and causing numerous infections, the likelihood of the virus mutating increases. The more opportunities a virus has to spread, the more opportunities it has to undergo changes.

Experts are constantly monitoring new variants of the coronavirus that causes COVID-19 to see if they spread more easily, cause more severe disease, or could have an impact on the effectiveness of public health measures or vaccines.

The best way we can limit the transmission of COVID-19 is for people to get the vaccine when available to them and continue to follow existing advice on preventing the spread of the virus, including physical distancing, wearing masks, regular handwashing and keeping indoor areas well ventilated.

Is the Delta variant more contagious? 

Yes. The Delta variant is highly contagious, about twice as contagious as previous variants. However, the same precautions, such as avoiding crowded spaces, keeping your distance from others and mask wearing, still work against the Delta variant.  

Are the COVID-19 vaccines effective against the Delta variant?  

Yes. The WHO-approved COVID-19 vaccines continue to be highly effective at preventing severe illness and death, including against the Delta variant. When it’s available to you, make sure to get vaccinated. If your vaccination involves two doses, it’s important to receive both to have the maximum protection.  

The vaccines protect most people from getting sick, but no vaccine is 100 per cent effective. A small number of vaccinated people may get infected with COVID-19; this is called breakthrough infection; however, the small number of vaccinated people who get infected with COVID-19, are likely to have milder symptoms. Therefore, if you live in an area with high-levels of COVID-19 transmission it's recommended to take additional precautions even if you are vaccinated. If you have been fully vaccinated but are showing symptoms of COVID-19, you should contact your doctor about whether you should get tested.

Read more about COVID-19 vaccines and explore what you need to know before, during and after getting vaccinated.

Are children more likely to contract the Delta variant? 

The Delta variant does not specifically target children. However, the Delta variant is more contagious than other strains and people who are mixing socially and those who are unvaccinated are more susceptible to contracting the Delta variant. 

Learn how to talk to your child about COVID-19.

How can I protect myself and my family against the Delta variant? 

Keep yourself updated on the level of COVID-19 transmission in your community and follow local guidance. In general, the higher the rate of transmission, the higher the risk of potential exposure in public settings. Here are some key ways to protect yourself and your loved ones: 

  • Avoid crowded spaces and keep your distance from others. 
  • Keep all indoor spaces well ventilated (this can be as simple as opening a window). 
  • Wear a mask when in public places where there is community transmission and where physical distancing is not possible.
  • Wash your hands regularly with soap and water or an alcohol-based hand rub.
  • When it’s your turn, get vaccinated. WHO-approved COVID-19 vaccines are safe and effective.    

Read mask tips for families.


This article was originally published on 19 August 2021. It was last updated on 23 September 2021.