More than 100,000 people have received their first dose but the figure is well short of what was promised with the rollout in its third week.

The government previously committed to four million people being administered jabs by the end of March and at least one dose being available to all adults by October.

Chief Medical Officer Paul Kelly and Health Department boss Brendan Murphy will front the Senate’s coronavirus response committee in Canberra on Thursday.

Medical experts outside government are adamant the October goal is more likely to be achieved by the end of the year.

But Professor Murphy has defended the speed of the rollout, which he argues doesn’t need to mirror other nations with high case numbers and death tolls.

“This is not a race,” he told reporters.

“We have no burning platform in Australia. We are taking it as quickly and carefully and safely as we can.

“We’re not like the US or the UK or most other countries in the world where they’ve got people in hospital dying.”

In January, Prime Minister Scott Morrison set the March target of four million which he later clarified to early April amid global supply pressure.

Now he says the speed of the rollout is “subject to events”.

But despite scepticism from experts, Morrison is sticking to the October population-wide timeline.

“We will get this done by October as we said we would,” he told Seven.

“But we’ve got to do it safe – as Brendan Murphy said, this is not a race – what is most important is the health and safety of Australians in the vaccination program and that’s what we’ve principally focused on.

The prime minister is confident the vaccine rollout will gain speed.

“Towards the end of this month we’ll see the Australian-produced vaccines coming into the program,” he said.

“That means we’ll be able to roll them out at around a million a week. When we get to that scale, I think we’ll see a real gear change.”

Deputy Labor leader Richard Marles said the opposition would hold the government to meeting its targets.

“Australians want to see the rollout obviously happen as safely as possible, as carefully as possible,” he told Sky News.

“But they also want to see it happen as quickly as possible, because that’s how we get through this.”

Between the Pfizer and AstraZeneca jabs, there are 1.3 million doses of overseas-produced vaccines now in Australia.

Murphy said recent data out of the UK had shown both options were on par after initial studies showed Pfizer was more effective.

About a quarter of the people who have received vaccines are in vulnerable categories such as aged care and disability residents.