Variants of the virus that causes COVID-19 are emerging and becoming dominant around the world.

So some vaccines are being updated to allow our immune system to learn how to deal with them.

But this process of identifying and characterising variants that can escape our immune system, then tweaking a vaccine to deal with them, can take time.

Researchers are designing a universal coronavirus vaccine. This could mean one vaccine to protect against different variants of SARS-CoV-2.