Nigeria expects to take delivery of 29-million doses of Johnson & Johnson Covid-19 vaccine in August, allowing it to ramp up its vaccination programme just as a third wave of infections takes hold, the health minister said.

Africa's most populous country has recorded close to 171 000 cases of the virus and 2 132 deaths since the start of the pandemic, according to official data, although the real figures are likely to be much higher as testing is patchy.

The government had announced in March it was hoping to secure 70-million doses of Johnson and Johnson vaccine this year through an African Union programme, with an initial batch of 30-million to be delivered in the third quarter.

Health Minister Osagie Ehanire told reporters that the single-dose vaccine would be "advantageous" for Nigeria given its partly nomadic population and weak systems for keeping track of people and arranging for second doses.

Ehanire said Nigeria was also expecting 4-million doses of the Moderna vaccine, 700 000 doses of the AstraZeneca vaccine and an unspecified quantity of Pfizer and Sinopharm doses. He said all of those were expected in the third quarter.

With an estimated 200-million citizens, Nigeria has so far vaccinated a tiny fraction of its population. The most recent data, in June, showed that 2-million people had received one dose and 700 000 had received two. In total, Nigeria has so far taken delivery of just under 4-million doses.

Ehanire said Covid-19 infection numbers were rising due to the spread of the highly contagious Delta variant. He said 216 people had tested positive in the last 24 hours, most of them in Lagos in the southwest and in the southern state of Akwa Ibom.

"It is worrisome that despite evidence of the emergence of a third wave of the Covid-19 pandemic, citizens continue to refuse adherence to public health advisories," he said, adding that many people returning from abroad were refusing to quarantine.