They began rolling it out before the final trial...

The country warned against vaccine nationalism that could lag the rollout of global shipments, the news agency reported.

The two-dose vaccine was developed by Gamaleya Research Institute of Epidemiology and Microbiology, a Russian medical-research institute headquartered in Moscow.

Though each dose targets the coronavirus's "spike", they use different vectors, the neutralized virus that carries the spike to the body. Once vaccinated, patients start to produce antibodies for COVID-19, meaning their immune systems will be ready to fight the disease when and if it is encountered. The vaccine can be stored at fridge temperature and will cost around $10, making it among the cheaper vaccines (but not the cheapest).

Registered by Russian Federation on August 11, 2020, Sputnik V became the world's first coronavirus vaccine.

The Gam-COVID-Vac is a two-part vaccine that includes two adenovirus vectors - recombinant human adenovirus type 26 (rAd26-S) and recombinant human adenovirus type 5 (rAd5-S) - which have been modified to express the SARS-CoV-2 Spike (S) protein.

Speaking to the media, the researchers stated that serious adverse events or those requiring hospital admission were rare in both the placebo and vaccine groups, and none were considered associated with vaccination.

The trial is now ongoing and aims to include a total of 40,000 participants.

The Lancet medical journal this week published results showing Sputnik V to be safe and 91.6% effective. "But the results reported here are clear, and the scientific principle of vaccination has been demonstrated, which means that the fight to reduce the incidence of Covid-19 can now be joined by another vaccine".

"Our interim analysis of the randomised, controlled, phase 3 trial of Gam-COVID-Vac in Russian Federation has shown high efficacy, immunogenicity, and a good tolerability profile in participants aged 18 years or older", Inna V Dolzhikova, co-lead author, Gamaleya national research centre for epidemiology and microbiology in Russian Federation, said.

Faced with hurdles with a vaccine roll-out in her country, German Chancellor Angela Merkel said on Tuesday that the Russian jab could be used in the European Union if it receives official approval.

The authors of the Lancet paper pointed out the analysis only included symptomatic cases of Covid, and more work would need to be done to understand whether it stops even asymptomatic cases, and prevents the virus from being passed on by vaccinated people.

A dozen countries have already approved the Russian vaccine for use, including Bolivia and Argentina, where Lpez-Gatell visited in January to learn more about it.

"Such pandemic-related vaccine rollout compromises have, to be fair, been adopted in the United Kingdom vaccination programme also - with the extended intervals between the first and second doses".