Coronavirus cases and hospitalizations in the United States are at a six-month high, fueled by the rapid spread of the Delta variant across swathes of the country grappling with low vaccination rates, Reuters reports.

Nationwide, infections have averaged 100,000 for three days in a row, up 35% over the past week, according to a Reuters tally of public health data. Louisiana, Florida and Arkansas reported the most new cases in the past week, based on population.

Hospitalizations rose 40% and deaths, a lagging indicator, registered an 18% uptick in the past week with the most fatalities by population in Arkansas.

The intensifying spread of the pandemic has led to cancellation of some large high-profile events. One notable exception is an annual motorcycle rally in Sturgis, South Dakota, which has been proceeding as planned.

Florida set records for hospitalizations for eight days in a row, according to the analysis. In that state, most students are due back in the classroom this week as some school districts debate whether to require masks for pupils.

The head of the nation's second-largest teachers' union on Sunday announced a shift in course by backing mandated vaccinations for U.S. teachers in an effort to protect students who are too young to be inoculated.

The number of children hospitalized with coronavirus is rising across the country, a trend health experts attribute to the Delta variant being more likely to infect children than the original Alpha strain.

With the virus once again upending Americans' lives after a brief summer lull, the push to vaccinate those still reluctant has gained fresh momentum. Three states -- California, New York and Virginia -- have mandated vaccinations or weekly testing for state employees, as well as several cities.

The administration of President Joe Biden set new rules late last month requiring federal workers to provide proof of vaccination or face regular testing, mask mandates and travel restrictions.

The Pentagon on Monday said that it will seek Biden's approval by the middle of September to require military members to get vaccinated.

In the private sector, a growing number of companies are also mandating vaccinations.

Patients wait in line to get a swab test at a COVID-19 mobile testing site hosted by the Manatee County Florida Department of Health in Palmetto, Florida, U.S., August 2, 2021.

US infections from Delta strain at six-month high