LONDON: There are around 4,000 variants of the virus that causes COVID-19 around the world now so all vaccine manufacturers including Pfizer Inc and AstraZeneca Plc are trying to improve their vaccines, a British minister said.

"Its very unlikley that the current vaccine won't be effective on the variants whether in Kent or other variants especially when it comes to severe illness and hospitalisation," Vaccine Deployment Minister Nadhim Zahawi told Sky.

"All manufacturers, Pfizer-Biontech, Moderna, Oxford-AstraZeneca and others are looking at how they can improve their vaccine to make sure that we are ready for any variant - there are about 4,000 variants around the world of Covid now."