Australia moved to reassure its citizens over the efficacy of AstraZeneca's Covid-19 vaccine after South Africa suspended use of the shot because data showed it offered limited protection against a new strain of the virus.

Citing data that showed the AstraZeneca vaccine reduced mild-to-moderate Covid-19 by 22 per cent, South Africa said it would put on hold the use of the AstraZeneca vaccine, according to Reuters.

But Australia's Minister for Health, Greg Hunt, said the vaccine is effective in its primary objective.

“There is currently no evidence to indicate a reduction in the effectiveness of either the AstraZeneca or Pfizer vaccines in preventing severe disease and death. That is the fundamental task, to protect the health,” Hunt told reporters in Canberra.