TOPEKA — Officials in two major Kansas health care systems on Tuesday urged people to resume wearing masks indoors even if they’ve been vaccinated against COVID-19 because of the faster spreading Delta variant.

The comments from administrator-doctors at Stormont Vail Health in northeastern Kansas and the University of Kansas Health System came just before the U.S. Centers for Disease Control and Prevention recommended that even vaccinated people wear masks indoors in places where the coronavirus is surging. Their comments also came the day after the school board in one of Kansas’ largest public school districts approved a mandate for elementary students to wear masks when classes resume in mid-August.

Republican U.S. Sen. Roger Marshall of Kansas immediately criticized the CDC’s new guidance, suggesting it would cause more people to hesitate to get vaccinated. Marshall, who is an obstetrician and not an epidemiologist, also argued that the CDC’s change in guidance was unnecessary.

Kansas has seen its daily average of new cases rise for nearly five weeks because of the Delta variant and the state’s low vaccination rate. The average has hit levels last seen in mid-February.

State data showed that Kansas averaged 653 new cases a day for the seven days ending Monday. While that’s a fraction of the worst peak in mid-November, it’s more than six times the average of 96 new cases per day for the seven days that ended June 23.

“First, we have to ask those who are unvaccinated to get vaccinated,” Dr. Steve Stites, chief medical officer for the University of Kansas system, said during a daily webcast. “But second, we all need to say to each other, ‘We all need to put our masks back on until we can get you vaccinated.'”

Democratic Gov. Laura Kelly said in a statement that her administration is reviewing the new CDC guidance and “we don’t intend to stop” following its recommendations. But she also didn’t specifically urge people to wear masks indoors, instead calling for more people to get vaccinated.

The University of Kansas system reported that it had 60 people hospitalized Tuesday at its main Kansas City, Kan., hospital, compared to only two at one point in March. Stormont Vail reported Tuesday that of its 133 positive COVID-19 tests over seven days, all but 17 of them — or 87% — were in unvaccinated people.

“Both vaccinated and unvaccinated individuals need to take precautions. It’s time to return to wearing masks, practice social distancing, and avoid crowded places,” Dr. Robert Kenagy, Stormont Vail’s president and CEO, said in a statement.

Meanwhile, the Shawnee Mission school board in the Kansas City area voted 6-1 on Monday night to require masks in elementary schools but keep them optional in middle and high schools, where children are old enough to get vaccinated, The Kansas City Star reported. The district has about 26,000 students and is the state’s third largest, behind Wichita and Olathe.

The CDC reported that 45% of Kansas’ population — or 1.3 million of its 2.9 million residents — were fully vaccinated as of Tuesday. But no vaccine has been authorized for children under age 12.

In Kansas, confirmed cases of the Delta variant have been doubling every two weeks, with the state health department reporting 1,338 as of Monday.

New cases began rising after top Republicans in the GOP-controlled Legislature in mid-June ended a state of emergency for the coronavirus pandemic. Kelly had wanted to keep it in place at least through August.

Republican state lawmakers also forced Kelly to accept limits on her power and the power of local officials to impose pandemic restrictions. Earlier this month, District Judge David Hauber in Johnson County struck down those limits and a new law that would have required unusually speedy decisions in lawsuits challenging pandemic restrictions.

Hauber on Tuesday rejected a request from Kansas Attorney General Derek Schmidt that the judge not have his order take effect while Schmidt appeals it. Schmidt, a Republican, is running for governor next year.

Kansas Republicans became increasingly hostile to mask mandates as the pandemic continued, particularly when new case numbers declined. Marshall earlier this month co-sponsored a bill to prevent federal agencies from imposing mask mandates for public transportation, a measure that remains in committee.

Marshall said vaccinations and natural immunity from COVID-19 infections “provide exceptional defense” against the Delta variant and other variants.

“Science shows us there is no reason to panic,” Marshall said.