Pfizer Inc. will ship 4.5 million doses of its COVID-19 vaccines to South Africa by June helping the nation ramp up its inoculation drive.

The first 325,260 doses will arrive Sunday night, Zweli Mkhize, South Africa’s health minister said in a statement.

The government also expects Johnson & Johnson to release stock from the Aspen Pharmacare Holdings Ltd.’s plant in the nation by the middle of May following a verification process with regulators, according to the statement. Aspen is making the J&J vaccines under license.

South Africa, which is the worst-affected country by the coronavirus pandemic on the continent, lags behind emerging market peers in vaccinations. It halted J&J vaccines after health agencies last month called for their suspension in the U.S.

The J&J shot is a key element to the nation’s vaccination plan and has already been used to inoculate health workers, with no reported adverse effects.

The government last month awarded tenders to state-backed Biologicals Vaccines Institute of Southern Africa Ltd. and Imperial Logistics Ltd. to import an unspecified quantity of doses, the Department of Health said in a document on its website.

DSV Healthcare Ltd. was contracted to store and distribute the doses countrywide.

The government ordered 30 million of the two-dose vaccine developed by Pfizer and BioNTech SE, which in addition to the J&J shots should be sufficient to inoculate more than two thirds of the nation’s 60 million population to achieve herd immunity.