When British Prime Minister Boris Johnson shared the grim news that a new, seemingly faster-spreading strain of the coronavirus was taking hold in parts of England this weekend, he said there was no evidence to suggest the mutation will be resistant to COVID-19 vaccines. But U.S. scientists at the Walter Reed Army Institute of Research are now poring over the data to see if there’s any reason to be concerned. Nelson Michael, director of the Center for Infectious Diseases Research at Walter Reed, told CNN: “It stands to reason that this mutation isn’t a threat, but you never know. We still have to be diligent and continue to look.” Michael said they should know in the next few days if there’s a concern about the mutation. In August, Walter Reed published a study showing that the developed vaccines worked against other mutations of the coronavirus.