Australia on Thursday revised its guidelines on the use of the Oxford-AstraZeneca COVID-19 vaccine, limiting it to those aged 60 and above due to new evidence of blood clotting disorders.

Speaking to reporters, Health Minister Greg Hunt said the government accepted the medical advice from the Australian Technical Advisory Group on Immunization (ATAGI), which said only over the 60s should now take AstraZeneca because of 12 new cases of a rare, but sometimes serious, blood condition.

-I have therefore recommended that Pfizer is the preferred vaccine for under the 60s,- he said.

The vaccine by the British-Swedish pharmaceutical company was recommended for use in people over 50, who will now be offered the Pfizer vaccine.

Paul Kelly, the chief medical officer, said the “risk-benefit equation” had changed for the over 50s because of the reported incidence of the blood clotting condition known as thrombosis with thrombocytopenia syndrome (TTS).

He, however, added: -AstraZeneca remains a very effective vaccine, and its benefits in the over 60s remain much higher than the risk of this particularly rare but sometimes serious syndrome.-

The official said that so far 815,000 people over the age of 50 had received the first AstraZeneca dose, urging them to go ahead with the second dose as well.

-The second important component of the advice [from ATAGI] is that anyone who has had the first dose of AstraZeneca without a problem should feel very confident to have their second dose- he said.

Australia has so far administered over six million COVID-19 vaccine doses, with 700,000 being fully vaccinated. As many as 30,301 cases and 910 related deaths have been recorded since the start of the pandemic.

Several countries, mostly in Europe, have limited or suspended the use of AstraZeneca over similar concerns. International health bodies, however, have time and again reiterated that its benefits outweigh any risks.