As United States health officials push to get more residents vaccinated, air passengers from around the world seem to be adjusting their travel itineraries.
They're flying through San Francisco International Airport for free COVID-19 shots that are not yet widely available in their home countries.
The shots are the single-dose Johnson and Johnson vaccine, and lately, about 80% of the appointments being booked at the airport's vaccine clinic are foreign travelers.
Seiichi Hosaka arrived from Fukuoka, Japan to get his shot before starting his six week business visit in the U.S.
"Couldn't get my shots in my city yet,” Hosaka said, who is visiting from Japan. “So, first thing was to get my vaccine here as soon as I arrived to San Francisco, and I'm very grateful for that."
In most countries around the world, the availability of any vaccines are still in short supply.
Booking a shot at the airport's clinic is open to anyone who's 18 or older with a photo ID.
Passports from 58 countries have been used there to get the shots.
"People from all over the world, they actually find out through social media,” said Alberto Evangelista, an assistant at the vaccine clinic. “And they sometimes connect their flight here just to get the vaccine."
The vast majority of appointments, about 80%, are currently being booked by foreign travelers. But local residents are also signing up.
Olena Velykanova is traveling to Europe this month and wanted to be fully vaccinated for the trip.
"Searched for a while, I was specifically searching for the Jenssen vaccine, because it's only one dose and I don't want to come twice,” said the San Francisco resident.
Because Americans have easier access to the double dose Pfizer and Moderna vaccines - both with slightly higher efficacy ratings - the Janssen-Johnson and Johnson shot is not as widely sought after these days.
So SFO has plenty of doses to dole out.
"It insures that these vaccine doses that are in our supply don't go to waste,” said Doug Yakel, airport spokesperson. “It insures that that they go to a good use. And that use and more, is coming from people who are having trouble accessing it in their home country."
Appointments can be booked so travelers can make sure it lines up with their travel schedule.
But for those who are on long layovers and may want to get the jab while they wait - they also take walk-ins.