WINDOW ROCK, Ariz. – The Navajo Nation on Monday reported 20 more COVID-19 cases, but no additional deaths.

The latest numbers pushed the tribe’s totals to 33,800 confirmed COVID-19 cases from the virus since the pandemic began more than a year ago. The known death toll remains at 1,442.

Based on cases from Sept. 10 to Sept. 23, the Navajo Department of Health issued an advisory for 40 communities because of an uncontrolled spread of COVID-19.

Navajo officials are urging people to get vaccinated, wear masks while in public and minimize their travel.

Officials said all Navajo Nation executive branch employees will need to be fully vaccinated against the virus by the end of this month or submit to regular testing.

The new rules apply to full, part-time and temporary employees, including those working for tribal enterprises like utilities, shopping centers and casinos.

Any worker who does not show proof of vaccination by Wednesday must be tested every two weeks or face discipline.

The tribe’s reservation is the country’s largest at 27,000 square miles and it covers parts of Arizona, New Mexico and Utah.