Virus properties and effects

All viruses change over time. Depending on where the changes are located in the virus’s genetic material, they may affect a virus’s properties, such as:

  • Transmission – for example, it may spread more or less easily
  • Severity – for example, it may cause more or less severe disease

We know that the COVID-19 vaccines have currently been approved are expected to provide at least some protection against new virus variants, and are highly effective against the Delta variant after 2 doses. Therefore, changes or mutations in the virus should not make vaccines completely ineffective.

If any of these vaccines prove to be less effective against one or more variants, it will be possible to change the composition of the vaccines to protect against these variants.

Learn more about the effects of the virus variants on Covid-19 vaccines here