The University of Oxford has said existing COVID-19 vaccines may protect against the Brazilian coronavirus variant as the P1 strain may be less resistant to antibodies than first thought.
A study by the university - which jointly developed the AstraZeneca coronavirus jab with the British-Swedish firm - examined the impact of natural and vaccine-induced antibodies on different strains.
The research, which has not yet been peer-reviewed, measured the level of antibodies that can neutralise - or stop infection from - variants that are circulating in South Africa, Brazil and elsewhere.
It found that vaccines do not work as well against the variants as against the original strain of coronavirus, but that the P1 Brazilian variant may be less resistant to vaccine-induced antibodies than first feared.
"These data suggest that natural and vaccine-induced antibodies can still neutralise these variants, but at lower levels," the university said.
"Importantly, the P1 'Brazilian' strain may be less resistant to these antibodies than first feared."
The study used blood samples from people who have natural antibodies generated from a COVID-19 infection and from those whose antibodies were induced by the Oxford or Pfizer vaccines.
It found a nearly three-fold reduction in the level of virus neutralisation by the antibodies generated by the Oxford and Pfizer vaccines for the Kent and Brazil variants when compared with the original strain, and a nine-fold and 7.6-fold reduction respectively against the South Africa variant.
The UK was the first country in the world to approve the Pfizer-BioNTech vaccine.
It is currently being rolled out across the nation, alongside the University of Oxford-AstraZeneca vaccine, which was given the green light by the Medicines and Healthcare products Regulatory Agency (MHRA) weeks later and administered to patients from the start of this year.
Approval of the Moderna jab followed, and the company said on Thursday that it expects to deliver its first COVID vaccines to Britain in April. A spokesman added that it is on track to meet its supply obligations.
It comes after ministers warned the vaccine rollout would be slower than hoped next month due to problems with international supplies.
Pfizer has said its deliveries to the UK for the first three months of the year "remain on track".
And AstraZeneca has said its UK domestic supply chain "is not experiencing any disruption and there is no impact on our delivery schedule".