As dozens of countries around the world isolate the U.K. in a bid to contain a new, rapidly-spreading variant of COVID-19, leading vaccine manufacturers Pfizer, BioNTech and Moderna are testing their shots against the strain and said that they are confident their vaccines remain effective against the mutated virus although testing to confirm this may take weeks.

U.K. officials say the new variant could be up to 70% more transmissible, though there is no evidence yet to suggest that it is more dangerous or able to make the virus less susceptible to vaccines, though further research will be needed to confirm this.

BioNTech CEO Ugur Sahin said he is confident the company’s vaccine will remain effective against the new variant, adding that “scientifically, it is highly likely that the immune response by this vaccine also can deal with the new virus variants”.