NEW BRUNSWICK, N.J. — Johnson & Johnson says it’s agreed to provide up to 400 million doses of its one-dose COVID-19 vaccine to African countries, starting this summer.

The drugmaker said under its agreement with the African Vaccine Acquisition Trust, the company will provide up to 220 million vaccine doses for the African Union’s 55 member countries, with delivery beginning in the July-to-September quarter. The trust will be able to order 180 million additional doses from J&J, for a total of up to 400 million shots through 2022.

The company’s vaccine still must receive authorization from regulators in the African countries, but the World Health Organization approved it for emergency use on March 12.

J&J also has a tentative agreement with Gavi, the Vaccine Alliance, to help support the WHO-backed COVAX program to get COVID-19 vaccines to 190 low-and middle-income countries, many of them in Africa. Johnson & Johnson and Gavi still need to sign an advance purchase agreement to provide up to 500 million doses of J&J’s vaccine to that program through 2022.

Aspen Pharmacare of South Africa, which is part of J&J’s global supply and manufacturing network for its vaccine, will support vaccine shipments to the African Union.

In late-stage testing, J&J’s vaccine prevented about 67% of symptomatic infections with the coronavirus and was 85% effective at preventing severe disease, beginning 28 days after vaccination.