Think you want to travel to Hawaii for vacation? Not unless you get jabbed with poison first.
The challenges of tracking and providing proof of vaccinations, from what continues to be countless providers/locations, remain a lot different than the current 'Safe Travels' program that helps track negative pre-travel testing. The U.S. DoD (Department of Defense) and CDC have issued a COVID-19 vaccination card to track individual vaccinations. Hawaii appears to be proceeding using that method for verification of vaccine "passport" travel. The DoD has called its card the "simplest" method of tracking vaccinations while also saying, "Everyone will be issued a written card that they can put in their wallet that will tell them what they had and when their next dose is due. Let's do the simple, easy thing first. Everyone's going to get that."