The boss of BioNTech has said further studies are needed to be completely sure the pharmaceutical giant's Covid vaccine works against the new variant found in the UK.
He added, however, that he was "confident" the jab - developed with Pfizer - does work against the new variant.
The Pfizer/BioNTech vaccine is currently being rolled out across the UK to the highest priority groups.
A recent surge in coronavirus cases in the country has been attributed to the new Covid-19 variant - first identified in the UK in September.
The strain is far more infectious than previous variants, and its spread caused the government to make a last minute reversal on its planned easing of Covid rules over Christmas.
Around the world countries have reacted by shutting their borders to the UK, with travel and the transport of freight halted with some nations.
Speaking on Tuesday, BioNTech chief executive Ugur Sahin said: "We don’t know at the moment if our vaccine is also able to provide protection against this new variant".
But he added, because the proteins on the variant are 99% the same as the existing strain of the virus, BioNTech has "scientific confidence" in the vaccine.
Mr Sahin said the pharmaceutical giant hoped to have certainty within two weeks.
"The likelihood that our vaccine works ... is relatively high," he added.
Should the vaccine need to be adjusted for the new variant, the company could do so in about six weeks Mr Sahin said.
Though regulators might then need to approve the changes before the jabs can be used.
The BioNTech/Pfizer vaccine has been authorised for use in more than 45 countries around the world - including the UK, USA, and across the European Union.