(Bloomberg) -- South Africa will take about three months to register another Covid-19 vaccine for general use after the already approved AstraZeneca Plc shot proved only minimally effective in preventing mild disease caused by a variant of the virus first identified in South Africa.

The country has started inoculations of health workers as part of a study using Johnson & Johnson vaccines.

“There is likely to be a significant lag period,” Health Minister Zweli Mkhize said in a presentation to the National Council of Provinces on Thursday.

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