Results published in medical journal The Lancet on Friday showed that Russia’s coronavirus vaccine produced an antibody response in all participants in early-stage trials, Reuters reported.

“The two 42-day trials – including 38 healthy adults each – did not find any serious adverse effects among participants, and confirmed that the vaccine candidates elicit an antibody response,” the report published by the journal said. The trials of the vaccine, named Sputnik-V, were conducted between June and July, involving 76 participants.

The medical journal, however, said that long-term trials were needed to determine the efficiency of the vaccine. “Large, long-term trials including a placebo comparison, and further monitoring are needed to establish the long-term safety and effectiveness of the vaccine for preventing Covid-19 infection,” it said.

Russia, which on August 11 announced that it has developed the world’s first coronavirus vaccine, has faced criticism from scientists and experts for not conducting Phase 3 trials to determine its safety. A vaccine is deemed safe to be commercially available only after Phase 3 – a much larger efficacy trial involving thousands of participants. The advanced trial began last week as Moscow mayor on August 26 called upon citizens to participate in the process.

Moscow has hailed the results of the publication, considering it an answer to the criticism the vaccine has faced. “With this [publication], we answer all of the questions of the West that were diligently asked over the past three weeks, frankly with the clear goal of tarnishing the Russian vaccine,” said Kirill Dmitriev, head of the Russian Direct Investment Fund, the country’s sovereign wealth fund which has backed the vaccine. “All of the boxes are checked. Now...we will start asking questions of some of the Western vaccines.”

Dmitriev said at least 3,000 people have been recruited for the large-scale trial and its initial results were expected in October or November. Health Minister Mikhail Murashko said that the country would begin mass vaccination from November or December, keeping its focus on high-risk groups.

Globally, around a dozen of drugmakers are conducting advanced trials. Many of them, including Britain’s AstraZeneca and the United States pharmaceutical companies Moderna and Pfizer, expect to get results on the efficacy and safety of the vaccines by the end of the year.

Meanwhile, Russia expects to produce 1.5 million and 2 million doses per month by the end of 2020. After this, it plans to boost production to 6 million. It would take nine to 12 months to inoculate the majority of the population, said Alexander Gintsburg, director of the Gamaleya Institute, which has developed the vaccine.

Russia has so far reported 10,11,987 cases of infection and the toll stood at 17,598, according to the John Hopkins University data.