Nigeria’s government started an online registration system for Covid-19 vaccinations on Monday, a day before the first doses arrive in Africa’s most populous country.

The National Primary Health Care Development Agency launched a website allowing Nigerians to enroll to receive a shot.

Priority will be given to healthcare professionals and top government officials, as well as security forces and those working in the oil and gas industry, the agency said on its Twitter account.

Nigeria is due to receive almost 4 million doses of the AstraZeneca Plc vaccine on Tuesday.

They are being supplied under the Covax facility, a World Health Organization-coordinated program to bolster developing countries’ access to coronavirus vaccines.