BRASILIA/MOSCOW: The Brazilian state of Bahia has signed an agreement to conduct Phase III clinical trials of Russia's Sputnik V vaccine against COVID-19 and plans to buy 50 million doses to market in Brazil, officials have said.

The Russian vaccine is being developed by Moscow's Gamaleya Research Institute and marketed by the Russian Direct Investment Fund (RDIF), which last month entered an agreement with the Brazilian state of Paraná to test and produce the vaccine.

Russia will sell up to 50 million doses of its COVID-19 vaccine, known as Sputnik-V, to Brazil's Bahia State, RDIF said in a statement.

Governor Rui Costa said an agreement was signed this week to undertake the trials and Bahia will receive an initial 500 doses as soon as Brazil's health regulator Anvisa approves the protocol for testing.

First supplies are due to start in November pending approval by Brazil regulators "with the consideration of results of post-registration trials", RDIF added.

Russia has touted Sputnik as the first vaccine against coronavirus to be registered in the world, even though Phase III trials have yet to be completed.

A Phase III trial is a large-scale one involving thousands of people - in Russia, 40,000 - over a longer stretch of time.

If the trials that are expected to start in October are successful, Bahia will look to market the Russian vaccine in Brazil through its pharmaceutical research center Bahiafarma, said Fabio Vilas-Boas Pinto, Bahia state Health Secretary.

Brazil is the world's third-hardest-hit country by coronavirus, with more than million confirmed cases.

A separate Phase III trial will also be conducted on 10,000 volunteers in Brazil in 2021, the technology institute for the state of Paraná said last week.

Paraná's Technology Institute, known as Tecpar, will be using imported doses for the tests, but will start producing the vaccine for Brazil's market in the second half of next year.

RDIF has already signed two deals to export the vaccine abroad. Kazakhstan is set to buy more than 2 million doses initially and could later increase the volume to 5 million doses.

It has also agreed to sell 32 million doses to a private company in Mexico, Landsteiner Scientific.

RDIF said this week it expects to supply up to 100 million doses of the vaccine to Latin America, around a fifth of what it expects to be able to produce annually through global manufacturing partnerships.

India will be producing 300 million doses of the vaccine.