BUDAPEST: As COVID-19 ravaged Hungary in April, Budapest resident Akos Sipos received his second vaccine dose, believing he was doing the right thing for his own health and to help end the pandemic.
But Sipos, 46, soon discovered that the vaccine he received, Russia's Sputnik V, disqualified him from travelling to a number of other countries where it hadn't been approved.
The nations include the United States, which is pushing forward with a new air travel policy that will make Sipos and many like him ineligible to enter.
"I thought it's better to get Sputnik today than a Western vaccine at some uncertain future time," Sipos, who works as a search engine optimisation specialist, said of his initial decision to receive the jab.
"But I couldn't have known at that time that I wouldn't be able to travel with Sputnik."
Starting Monday, the United States plans to reopen to foreign travellers who are fully vaccinated against the coronavirus.
But there's a catch: non-immigrant adults need to have received vaccines authorised by the Food and Drug Administration or which received an emergency use listing from the World Health Organisation.
That leaves many hopeful travellers across the globe who have taken full courses of vaccines widely used in other parts of the world, Sputnik V and the China-produced CanSino jab, in particular, scrambling to get reinoculated with shots approved by U.S. authorities.
Two other Chinese vaccines, Sinopharm and Sinovac, have been approved by the WHO and will thus be accepted for travel into the U.S.
Mexico received nearly 12 million doses of CanSino and almost 20 million of Sputnik V after shipments began earlier this year.
Residents who got the required two shots of those vaccines now are looking to top up with shots of the Pfizer, Moderna, AstraZeneca or Johnson & Johnson vaccines, hoping that will make them eligible to cross the border.
"They screwed those of us who got this vaccine," said Rosenda Ruiz, 52, a public relations manager in Mexico City who received Sputnik V.
"There are lots of Mexicans who want to travel, but we can't. I am thinking of getting whatever other vaccine I can get."
While Sputnik V is used in around 70 countries worldwide, it has still not been approved by either the FDA or the U.N. health agency.
Nearly 1 million people have received the vaccine in Hungary, a Central European country of around 10 million.
Hungary was one of only two countries in the 27-member European Union to roll out the Russian vaccine.
Fewer than 20,000 people received it in Slovakia.
Judit Molnar, president of the Association of Hungarian Travel Agencies, says so many Hungarians being unable to travel to the United States, or even to some countries in the EU which don't accept the jab, has had an effect on her industry.
"We see that in the last few months, travellers are increasingly asking us when they can travel to America," said Molnar, who is also president of the OTP Travel agency.
"These travellers are saying they really hope the situation will change and that the United States will accept the Sputnik vaccine. There are many people who would like to travel and in Hungary, many people were vaccinated with Sputnik," she said.
Citizens of Russia, where use of Sputnik V is most widespread, also are seeking Western-approved shots so they can travel abroad.
Faced with the prospect of being turned away from flights, Russians have booked tours to Serbia, which has authorised use of the Pfizer-BioNTech, China's Sinopharm and the AstraZeneca vaccines in addition to Sputnik V.
Russia, which unveiled Sputnik V with much fanfare as the world's first registered vaccine in August 2020, criticised U.S. plans to leave the vaccine off its list of approved shots.
"There are exactly zero reasons for such decisions," Leonid Slutsky, chairman of the foreign relations committee in the Russian Duma, or lower house of parliament.
"The effectiveness and safety of the Sputnik V vaccine has been proven not only by specialists, but also by its practical application."
But the World Health Organisation still is reviewing the vaccine, and months of holdups make it unclear when Sputnik V might receive an emergency use listing.
Hungary's government has made bilateral agreements with 24 countries, including Russia, Serbia, Mongolia, Georgia, and Kazakhstan, on mutually recognising proof of vaccination, regardless of vaccine type.
Hungary's Ministry of Foreign Affairs told The Associated Press that it is open to a similar agreement with the United States, but "currently there is no ongoing negotiation."
Sipos, the search engine specialist, said that while he was confident in Sputnik V's efficacy, he recently sought a Western-approved booster shot, Moderna, so he could travel where he wants.
"I felt deceived because they accept Sputnik in more than 60 countries in the world, but in tons of other countries they don't," he said.
Silvia Morales, 38, a public high school teacher in Monterrey, Mexico, said she recently received a Moderna shot after hearing that the U.S. government wouldn't recognise her CanSino vaccine.
She said she "needed to have peace of mind" about her level of protection against the virus.
"But I also love travelling to the United States," she said.