Cavaleri added that the EMA would say there is a link although the regulator would not likely be in a position this week to give an indication regarding the age of individuals to whom the AstraZeneca shot should be given.
A heath chief from the European Medicines Agency (EMA) has said that there is a link between AstraZeneca's Covid-19 vaccine and blood clots. "But we still do not know what causes this reaction".
Australia began vaccinations much later than some other countries due to low case numbers, recording just under 29,400 COVID-19 cases and 909 deaths since the pandemic began.
Scientists are exploring several possibilities that might explain the extremely rare brain blood clots that occurred in individuals in the days and weeks after receiving the AstraZeneca vaccine.
However, the EMA then conducted an investigation into the vaccine, and found that the benefits outweigh the risks and it should continue to be used.
Authorities had pledged to administer at least 4 million first doses of the vaccine by end-March, but could only vaccinate 670,000 after the European Union blocked AstraZeneca vaccine exports to Australia in the wake of the drugmaker's failure to meet its shipment pledge to the bloc.
An investigation is also underway in the United Kingdom, where researchers are looking at the possibility of links between the AstraZeneca vaccine and rare blood clots.
Twomey also blamed the slow rollout on a lack of co-ordination between the Australian national government and states, with the latter complaining about slower-than-expected distribution and a lack of certainty on vaccine supplies.
The EMA last week recommended that countries should keep using the AstraZeneca vaccine because the benefits outweighed the risks, as countries including Italy suspended their rollout of the jab.