Utah Gov. Spencer Cox (R) apologized on Monday after his administration discovered a state agency had inadvertently misstated the number of residents who had received a vaccine against the coronavirus. 

In a letter to his constituents, Cox said some federal doses had been double-counted. The new count means just over 67 percent of Utah adults have received at least one dose of vaccine, not the 70 percent reported last week.

“We screwed up. And I sincerely apologize,” Cox wrote. “When I became governor, I promised that I would hold myself and others in state government accountable and admit our mistakes.”

“While federal data sharing has been extremely difficult, this one is on us. Our data team is devastated and embarrassed. And so am I,” Cox wrote. “Our data team at the Department of Health has been incredible throughout this pandemic. At times working around the clock, these public servants have been recognized as one of the most thorough and transparent data teams in the country. While this miscalculation is inexcusable, they have re-examined processes to prevent this type of error from happening again.” 

The error means Utah has not yet reached the 70 percent threshold by which most health experts expect herd immunity to kick in. But the state still ranks among the fastest to vaccinate such a large share of its population, especially as vaccine hesitancy grows among conservative populations. 

Only two other states that voted for former President Trump in the 2020 election — Nebraska and Florida — have vaccinated a higher share of their populations, according to data from the Centers for Disease Control and Prevention. 

Cox, 46, is just months into his first term as governor. He won election with 63 percent of the vote after running an advertisement alongside his Democratic rival calling for more civil discourse in politics.