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

Thousands of variants of the type of coronavirus that causes COVID-19 have been documented as the virus mutates, including the so-called British, South African and Brazilian variants which appear to spread more swiftly than others.

"Its very unlikely 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 News.

"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."

While thousands of variants have arisen as the virus mutates on replication, only a very small minority are likely to be important and to change the virus in an appreciable way, according to the British Medical Journal.

"We have the largest genome sequencing industry - we have about 50 per cent of the world's genome sequencing industry - and we are keeping a library of all the variants so that we are ready to respond - whether in the autumn or beyond - to any challenge that the virus may present and produce the next vaccine," Zahawi said.

The novel coronavirus - known by scientists as SARS-CoV-2 - has killed 2.268 million people worldwide since it emerged in China in late 2019, according to Johns Hopkins University of Medicine.