The head of the US Centers for Disease Control and Prevention has urged Michigan’s governor to shut down the state instead of asking for more vaccines as a way to control a sudden jump in coronavirus cases.

Rochelle Walensky, the CDC director, said on Monday she thought Michigan should impose fresh restrictions to combat the rapid spread of the disease, adding that a bumper delivery of vaccines would arrive too late to halt the uptick in cases.

Her comments mark a rare political intervention from the US public health body, which has so far largely remained happy to issue guidelines and let states set their own lockdown rules. They also reflect growing tension between Gretchen Whitmer, the state’s governor, and the federal government over how to quash a regional leap in cases which experts warn could sweep the whole country before enough people are vaccinated to stop it.