The United States has reported an eight per cent rise in new COVID-19 cases to 490,000 last week, the fourth week in a row infections have increased.
In the week ending April 11, Michigan reported the highest number of new cases per capita of all 50 states and also led the country in hospitalisations per capita.
About 39 per cent of new cases in Michigan were of the more contagious B.1.1.7 variant first identified in the United Kingdom, the highest percentage in the United States, according to Centers for Disease Control and Prevention data collected over a four-week period.
At the same time that cases were starting to rise in early March, Michigan relaxed COVID restrictions.
CDC director Rochelle Walensky says Michigan should "shut down" to combat the surge in cases, hospitalisations and deaths.
"The answer to that is to really close things down, to go back to our basics, to go back to where we were last spring, last summer and to shut things down," Walensky said at a news briefing on Monday.
Deaths from COVID-19, which tend to lag infections, fell seven per cent to 5325 last week, excluding a backlog of deaths reported by Oklahoma.
Last week, Oklahoma reported 1716 deaths between August and February that had gone unreported due to error. Including that backlog, deaths rose 21 per cent.
The average number of patients in hospitals rose six per cent to more than 39,000, increasing for a second successive week.
For a seventh week, vaccinations set a record, with an average of 3.1 million shots per day last week.
As of Sunday, 36 per cent of the US population has received at least one dose and 22 per cent are fully vaccinated.
New Hampshire is the first state to give a least one dose to more than half its residents.
Australian Associated Press