WINDOW ROCK, Ariz. — All Navajo Nation executive branch employees will need to be fully vaccinated against the virus that causes COVID-19 by the end of September or face regular testing. Tribal President President Jonathan Nez announced the new rules on …WINDOW ROCK, Ariz. — All Navajo Nation executive branch employees will need to be fully vaccinated against the virus that causes COVID-19 by the end of September or face regular testing. Tribal President President Jonathan Nez announced the new rules on …