MOSCOW (AFP) - Early clinical trials of a second Russian coronavirus vaccine have proved successful, its developer said on Thursday (Oct 1) after Russia boasted of approving the world's first vaccine.

Russia's Vektor - a top-secret state virology research centre in Siberia - said that early-stage trials were successful for its own experimental vaccine, named EpiVacCorona.

"The first two phases of clinical trials demonstrated the effectiveness and safety of the EpiVacCorona vaccine," Vektor's press department told the Interfax news agency.

Russia announced in August that it had developed the world's first registered vaccine - named "Sputnik V" after the world's first satellite.

It raised concerns among Western scientists by announcing that the vaccine - developed by Moscow's Gamaleya research centre - had received approval before full clinical trials have been completed.

Vektor said it would be possible to make the final conclusions about the efficacy of its vaccine, based on peptides that trigger an immune response, after post-approval clinical trials have been completed.

Russian Health Minister Mikhail Murashko told President Vladimir Putin this week that Vektor's vaccine could be approved by the ministry in three weeks.

Vektor said post-registration clinical trials would begin on 5,000 volunteers in Siberia.

The lab said there would be a separate clinical trial involving 150 volunteers who are over 60 years of age.

After that Vektor will begin placebo-controlled trials on 5,000 Russian volunteers between the ages of 18 and 60.

The EpiVacCorona vaccine is a two-component vaccine, and the interval between the administration of the first and second components is 21 days.

Russia plans to manufacture an initial 10,000 doses, Vektor said, with production expected to begin in November.

Vektor declined to comment when contacted by AFP and referred all queries to Rospotrebnadzor, the country's consumer safety watchdog.

The watchdog declined immediate comment.

The Vektor laboratory complex conducted secret biological weapons research in the Soviet era and stockpiles viruses ranging from Ebola to smallpox. It is located outside the Siberian city of Novosibirsk.