OLYMPIA, Wash. (AP) — The leader of Washington state’s wildfire response is calling on federal agencies to take the additional step of requiring COVID-19 vaccinations among their wildland firefighting forces to secure the country’s wildfire response capability.

In a letter Monday to U.S. Interior Secretary Deb Haaland and Agriculture Secretary Tom Vilsack, State Commissioner of Public Lands Hilary Franz also called for the deployment of federal resources to make vaccinations available at all fire camps on federal land.

The Washington Department of Natural Resources is making vaccines available within its jurisdictions at fire camps amid the rapidly spreading delta variant after Franz on Monday directed all DNR employees including firefighters to be fully vaccinated against COVID-19 by Oct. 18.

“Given the increased fire danger and deployment of federal firefighting forces across the Western United States, our mandate alone will not fully protect firefighters from the spread of COVID-19,” Franz wrote. “We cannot combat the increasing threat of catastrophic wildfire, however, without first prioritizing the health and safety of the firefighters who are on the frontlines.”

Last week, a federal crew headed to the Muckamuck Fire in north-central Washington was forced to turn back due to its members contracting COVID-19, Franz said.

She also said Washington DNR and contracted personnel are experiencing increased rates of COVID-19 infection as the peak of fire season nears. Because of infections among firefighters and pilots, firefighting engines have been pulled away from fires and aircraft have been grounded, she said.

She said the state can’t afford to lose a single firefighter when resources are already stretched thin.

With more than 1,650 fires this year, Washington has already surpassed the total number of fires that happened in all of 2020, she said.