South Africa aims to vaccinate around 1.1 million people against COVID-19 by the end of March as it ramps up its immunization programme, Health Minister Zweli Mkhize said on Thursday.

Addressing parliament, Mkhize also said authorities might have to inoculate more than their original target of 40 million people to reach herd immunity.

The country, hit far harder by the pandemic than any other in Africa, started rolling out Johnson & Johnson’s (J&J) vaccine last week in a research study targeting healthcare workers. It hopes to receive doses of the Pfizer vaccine soon.

Mkhize said so far more than 32,000 health workers had been given the J&J shot.

Previously, South Africa said it had secured 20 million doses from Pfizer and 9 million from J&J.

But Mkhize said those numbers were just “opening negotiations” and final volumes were likely to be different. “Once it is finalised we will announce new numbers very soon,” he said.

Authorities had estimated that, to ensure population herd immunity, at least 40 million people needed to be vaccinated.

However, “as we go on with our discussions, it does appear we may have to do more than 40 million,” Mkhize told parliament’s upper house.

Mkhize, a trained medical doctor, said on Tuesday that government advisers had grouped COVID-19 vaccines into three categories and those considered for “immediate use” were the J&J, Pfizer and Moderna shots.

A health ministry presentation on Thursday said “full licensing” through local medicines regulator SAHPRA for J&J’s vaccine could take “a couple of months”.

South Africa has recorded around 1.5 million COVID-19 cases and 49,500 deaths to date, respectively over one-third and almost half of Africa’s totals.