MOSCOW, Russia (AP) — Belarus and Argentina launched mass coronavirus vaccinations with the Russian-developed Sputnik V shot on Tuesday, becoming the first countries outside Russia to roll out the vaccine, which has faced criticism over the speed with which it was approved.

The first batch of Sputnik V arrived in the former Soviet republic of Belarus on Tuesday and the vaccination effort began almost immediately.

“A new stage starts in Belarus today with mass vaccinations against COVID-19. Medical staff, teachers, and those who come into contact a lot of people due to their jobs will be the first to get vaccinated. Vaccination will be entirely voluntary,” Belarus Health Minister Dmitry Pinevich was quoted as saying in a statement issued by his ministry and Russian health authorities.

Hours later, a similar campaign kicked off in South America as Argentine medical workers began receiving the vaccine and officials insisted it was safe. President Alberto Fernández called it the largest vaccination campaign in the country’s modern history.

Teachers, those with complicating medical conditions and people over 60 were to be next in line in Argentina, which so far has received 300,000 doses, which also will be free and voluntary.

Argentina, a country of 45 million people, has recorded nearly 1.6 million infections with the new coronavirus and almost 43,000 deaths.

Belarus conducted its own trial of Sputnik V among 100 volunteers and gave the shot regulatory approval on December 21, two days before Argentina did.

Russia has been widely criticized for giving the domestically developed Sputnik V regulatory approval in August after the vaccine only had been tested on a few dozen people. An advanced study started shortly after the vaccine received the Russian government’s go-ahead.

Russian health authorities say the study has now covered more than 30,0000 people, with data suggesting the virus was 91 per cent effective. That’s still far fewer cases than Western drug makers have accumulated during final testing to analyze how well their candidates worked, and important demographic and other details from the study have not been released.

Former Argentine Health Secretary Adolfo Rubinstein complained that his country’s authorities had approved the vaccine based on “a memo lacking data.”

“I don’t doubt that Sputnik V is an effective and safe vaccine,” he said. “But the best way to undo a lack of confidence is with information,” he said.

Belarus has reported nearly 190,000 confirmed coronavirus cases and about 1,400 deaths since the start of the pandemic, but many in the Eastern European nation of 9.4 million people suspect that authorities are manipulating statistics to hide the true scope of the country’s outbreak.

President Alexander Lukashenko, who has faced months of demands by protesters to step down after an August election they say was fraudulent, has cavalierly dismissed the coronavirus. He shrugged off the fears and national lockdowns the new virus had caused as “psychosis” and advised citizens to avoid catching it by driving tractors in the field, drinking vodka and visiting saunas.

His attitude has angered many Belarusians, adding to the public dismay over his authoritarian style and helping to fuel months of post-election protests.

Opposition figures say Lukashenko’s government has allowed COVID-19 to run rampant in jails where it has detained thousands of protesters.