Washington (AFP) - Health authorities expressed concern on Wednesday over rising coronavirus cases in the northern US state of Michigan despite a stepped-up vaccination campaign.
Joneigh Khaldun, the state's chief medical executive, warned on Twitter of a "significant increase" in cases.
"Our hospitalizations are going up as well. Michiganders need to double down and take the steps to help stop the spread of this virus," she said.
Michigan is seeing more Covid infections by population than any other US state and some experts have attributed the rise to spring vacations.
Rochelle Walensky, director of the US Centers for Disease Control, said her staff were "working closely" with the state of Michigan and its health officials.
"We have CDC teams on the ground working to assess outbreaks in correctional facilities," she said. "We're working to facilitate increased testing that is happening on the ground in the context of youth sports."
Walensky said the CDC was also seeking to "understand what is happening" with Covid-19 variants.
Despite administering more than three million vaccinations a day nationally, the number of new cases has begun to rise again in the United States and there have been around 63,000 new cases a day on average during the last week.
While infections have been going up, the number of deaths has been falling thanks to increased vaccination of "vulnerable" populations, Walensky said.
