The first peer-reviewed results of Phase 1 and Phase 2 clinical trials of Russia’s coronavirus vaccine, which is named Sputnik-V, have been published in the medical journal The Lancet on Friday.

Results from the two 42-day trials – which each included 38 healthy adults – “have a good safety profile with no serious adverse events” among participants, The Lancet said in a press release, noting that the vaccine-induced antibody responses in all participants.

Russia faced criticism last month when it announced the world’s first approved coronavirus vaccine for public use, even before Phase 3 trials are completed. 

Russia also faced scepticism over how quickly the vaccine was registered and the initial lack of scientific data around the clinical trials. 

Naor Bar-Zeev, deputy director of the International Vaccine Access Center at Johns Hopkins University said in a linked comment that the studies are “encouraging but small,” according to The Lancet. Bar-Zeev was not involved in the Russian study, but peer-reviewed it.