The exceedingly fluid nature of COVID-19, and its impact on Hawaii’s economy, is manifesting itself again — via uneven Safe Travels rules among counties, now overlaid by new uncertainty over federal travel vaccination guidelines.

Come Monday, Kauai opts back into Safe Travels, a statewide program that allows travelers to bypass a 10-day quarantine if they’ve taken, and passed, a pretravel COVID-19 test 72 hours before arrival. Kauai in early December temporarily opted out of the program amid a worrisome surge in COVID cases; the only way arrivals there could avoid full quarantine was to stay in a “resort bubble” at one of nine approved properties, take a COVID test three days after arrival, then be allowed to leave only after getting a negative result.

That undoubtedly helped to tamp Kauai’s COVID cases — but unfortunately, also suppressed economic recovery. Kauai’s promising reentry into Safe Travels on Monday comes as it regains control over COVID counts; adds hospital-bed capacity; and embraces a brisk pace of vaccinations, which, starting today, will open up to all Kauaians age 16 and up.

Hawaii island, too, begins vaccinations today for residents 16 and older. The Big Island, even as it has followed Safe Travels protocols, additionally requires arrivals to undergo a rapid COVID test at the airport upon landing.

As Kauai readies to reenter the Safe Travels program, however, Maui is now looking to change its arrivals policy, spooked by recent clusters of COVID cases traced to one church and a housing complex. On top of the 72-hour pretravel test, Maui’s mayor is asking for Ige’s approval to require arrivals to clear a COVID post-travel test at the airport. Additionally, Maui is seeking approval to start a pilot program for a vaccination passport — allowing travelers who show proof of full vaccination to enter Maui without having to pretest or to quarantine.

That passport request got a favorable boost Friday, it would seem, when the U.S. Centers for Disease Control and Prevention updated its guidelines, saying people fully vaccinated against COVID can travel within the U.S. without getting tested or quarantined.

Of course, how Hawaii reacts to the new CDC guidance, and how to verify fully vaccinated arrivals will be the next-step discussions.

With travel bookings starting to accelerate, consistency across the island chain is needed to minimize traveler confusion. Still, as Hawaii muddles through balancing traveling protocols with public health, one constant remains: the “3 Ws” imperative of wearing masks, watching social distancing and washing hands.