Russian scientists say the country’s Sputnik-V vaccine appears safe and effective against COVID-19, according to early results of an advanced study published in a British medical journal.

Researchers say that, based on their trial, which involved about 20,000 people in Russia last fall, the vaccine is about 91 percent effective in preventing people from developing COVID-19. The study was published online on February 2 in the journal, The Lancet.

Scientists not linked to the research acknowledged that the speed at which the Russia vaccine was made and rolled out was criticized for “unseemly haste, corner cutting and an absence of transparency.”

“But the outcome reported here is clear,” British scientists Ian Jones and Polly Roy wrote in an accompanying commentary. “Another vaccine can now join the fight to reduce the incidence of COVID-19.”

The Sputnik-V vaccine was approved by the Russian government with much fanfare on August 11. At the time, the vaccine had only been tested in several dozens of people.

Some early results were published in September, but participants had only been followed for about 42 days and there was no comparison group.

The data release comes as Europe scrambles to secure enough shots for its 450 million citizens due to production cuts by AstraZeneca and Pfizer while the U.S. roll-out has been hampered by the need to store shots in ultracold freezers and uneven planning across states.

With reporting by AFP, Reuters, and AP