According to Reuters, African countries are gearing up to approve a new malaria vaccine, with 20 million pills ready for purchase this year.

Nigeria’s pharmaceuticals authority followed Ghana’s lead this week, making the two countries the first in the world to support the novel R21 vaccine, designed by Oxford University scientists and manufactured by the Serum Institute of India and Novavax.

The move was unusual as it came before the World Health Organization’s approval. African countries that do not have extensive resources for drug regulation have previously relied on the U.N. agency to initially review new medicines. Detailed data on the malaria vaccine from large-scale trials are not yet publicly available, and it is not clear how the poorest nations will pay for the shot.

But the urgency of addressing a disease that kills more than 600,000 people annually, most of them children under age 5 in Africa south of the Sahara, and recent efforts to enhance drug oversight in the region, are changing the process.

At least 10 other African countries’ regulatory authorities are reviewing trial data to assess the shot and more of them are expected to approve it in the coming weeks, the WHO said at a high-level meeting this week.

“We expect many more countries to come through,” Mary Hamel, the WHO’s malaria vaccine implementation head, told the expert meeting on Tuesday. “They are sovereign countries that can make their own decisions for their vaccines.”

She did not name which countries may be next, although Tanzania and Kenya have strong regulators and among the highest rates of the disease.

Oxford scientist Adrian Hill, a lead developer of the vaccine, said the shot has remained around 70%-80% effective in late-stage trials. A malaria shot from GSK Plc, which has been authorized by WHO but has yet to become widely available due to lack of funding, is thought to be somewhat less effective.

Serum Institute Chief Executive Adar Poonawalla told Reuters his company will produce 20 million doses of the Oxford shot “at-risk” in the next two months. That means they do not yet have a buyer lined up among African governments or nonprofit organizations that often procure for poorer countries.

“We are committed to making the R21 vaccine available to people who need it most,” Poonawalla said.

The supply would be enough to inoculate 5 million children with the vaccine’s 4-dose regimen and would be available in time for the upcoming malaria season, Poonawalla said, which begins in June depending on the country.

At $3 per dose, the supply is worth around $60 million. Serum declined to comment further on negotiations for the shot.