The Hopi and Navajo Nations have reported no cases of COVID-19 on their reservations as of March 9 as the virus continues its spread across the globe. The Navajo Nation issued a travel advisory for its people March 4.The Hopi and Navajo Nations have reported no cases of COVID-19 on their reservations as of March 9 as the virus continues its spread across the globe. The Navajo Nation issued a travel advisory for its people March 4.