Russia's COVID-19 vaccine was safe and showed signs of an immune response, according to early research.

Last month, Russia announced that its vaccine named Sputnik V had already received approval. Russia became the first nation to approve a COVID-19 vaccine after two months of human testing. 

According to research published in The Lancet Friday, the results of two trials done from June to July this year that involved 76 participants showed 100 percent of them developing antibodies to COVID-19, without any serious side effects.

Russia licensed the two-shot jab for domestic use in August. Each participant was given a dose of the first part of the vaccine and then given a booster with the second part 21 days later. They were monitored over 42 days. 

In the Lancet study, Russian researchers reported that the two 42-day trials, each involving 38 healthy adults aged between 18 and 60, did not cause any serious adverse events and affirmed that vaccine candidates produced an antibody response to the new coronavirus.

The researchers also underlined that "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."

The vaccine was named Sputnik V to honor the Soviet Union's launch of the world's first satellite into space in 1957. Some health experts have issued warnings against the use of Sputnik V until all internationally approved testing, and regulatory steps have been taken.

A senior Russian official said that Moscow had faced down its critics abroad with the results now published for the first time in an international peer-reviewed journal.

Kirill Dmitriev, the head of the Russian Direct Investment Fund (RDIF), said that with the publication of their COVID-19 vaccine's results, they had answered all the questions of the West that were asked over the past three weeks.

Dmitriev said that these questions frankly have a clear goal of tarnishing the reputation of the vaccine. 

"All of the boxes are checked. Now... we will start asking questions of some of the Western vaccines," Dmitriev said. The RDIF is Russia's sovereign wealth fund and is backing the vaccine. 

Lead author Dr. Naor Bar-Zeev of the International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, commented on the early-stage trials' results by saying that the studies were "encouraging but small."

According to The Lancet, the Sputnik V vaccine produced a response in an immune system component known as T cells during the early-stage trials.

Moscow's Gamaleya Institute develops the vaccine. It is administered in two doses, with each based on a different vector that normally causes the common cold.

Some experts said that using this delivery mechanism could make vaccines less effective since many people have already been exposed to adenovirus and developed immunity to it.

Russia said it aims to produce between 1.5 million and two million doses per month of this potential COVID-19 vaccine by the end of the year. Russia further noted that they would then gradually increase its production to six million doses a month.

Earlier, U.S.'s top infectious disease expert Dr. Anthony Fauci has expressed doubts about Russia's COVID-19 vaccine. He was skeptical that Russia's vaccine has proved to be safe and effective. 

"Having a vaccine... and proving that a vaccine is safe and effective are two different things," Fauci said. 

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