WINDOW ROCK, Ariz. (AP) – 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 be required to submit to regular testing, according to an executive order announced by …WINDOW ROCK, Ariz. (AP) – 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 be required to submit to regular testing, according to an executive order announced by …