At least 67% of South Africans will need to be vaccinated against Covid-19 to ensure herd immunity, health minister Zweli Mkhize has announced during a public briefing.

On Sunday, Mkhize unveiled the government's strategy to secure vaccines and roll them out to two-thirds of South Africa's 57-million citizens, saying the government was currently in discussions with several manufacturers.

The vaccine is expected to be rolled out in three phases, with the 1.25-million healthcare workers in the country having first access.

A second phase will see essential workers - such as miners, teachers and police officers - and those living in congregate settings, such as care centres and prisons, offered the vaccine. The second phase, which will require roughly 16-million vaccines, will also include those over 60 and those with comorbidities.

The third phase will see vaccines being made available to an additional 40-million citizens.

Mkhize added the Covax agreement would see enough vaccines to cover 10% of the population delivered by the second quarter of 2021, but enough vaccines to cover the remaining 57% of the population would have to be sourced through bilateral agreements.

The government is currently in discussions with several pharmaceutical companies, including Pfizer, Moderna, Johnson and Johnson, and Astra Zeneca.

He said non-disclosure agreements had been signed with these companies, meaning the government was able to share only limited information on the discussions.

According to the deputy director-general of the health department, Dr Anban Pillay who spoke at the briefing, these discussions could result in vaccines being delivered in the first quarter of the year.