They were two clunky cultural references primed for TV news.

“The eagle has landed,” Health Minister Greg Hunt announced on Monday, declaring 142,000 doses of the Pfizer vaccine had touched down in Australia — after much nervousness.

And then, the next day “AstraZeneca is cleared for lift-off” he said, before announcing the Therapeutic Goods Administration had approved the AZ vaccine for use for all Australians — with some caveats.

Keeping the references going, vaccine news — in particular this week — has been travelling at warp speed.

But the two announcements, one day after another, are critical to Australia’s upcoming vaccine rollout — what the government is calling the biggest logistical exercise the country has ever seen.

It means the main vaccine to be rolled out in Australia — and manufactured by biomedical company CSL at 50 million doses at 1 million doses a week from late March — is approved and ready to go.

It also means Australians now have some certainty on a few things:

• The first jabs of the vaccine will start on Monday
• The states have been given 50,000 doses of Pfizer to divvy up between them, with most, unsurprisingly, deciding to focus on hotel quarantine workers
• They, along with frontline healthcare workers, will be vaccinated at “16
• Pfizer vaccination hubs” spread across the country from Monday
• The Government will also begin vaccinating aged care residents with the Pfizer vaccine from Monday

The list of knowns, right now, is small.

The list of unknowns is much bigger.

And the most immediate unknown revolves around the continued delivery of Pfizer vaccine into the country.

Right now, as the world scrambles for vaccines, the Government does not know — or is not revealing — exactly when the second delivery will touchdown, or the third or fourth.

And it also does not know how much Pfizer vaccine it will receive in early deliveries.

Scott Morrison and a vial of the AstraZeneca vaccine. Photo: AAP

A spokesperson for the Health Minister told the ABC: “Our initial weekly allocation [of Pfizer vaccine] is 142,000 for this week, with further doses to be confirmed weekly.”

“The Commonwealth continues to work closely with Pfizer and the states and territories on the delivery schedule for rollout of the COVID-19 vaccination program.”

Earlier this week, the Health Minister confirmed Australia is expecting a minimum of 1 million doses a month from April, as part of its initial agreement with Pfizer for 10 million doses.

Timing for the “further agreement” for an additional 10 million doses during 2021 is “to be confirmed”.

The first 142,000 Pfizer doses which arrived in Sydney on Monday. Picture: Twitter

According to former Health Department secretary Stephen Duckett, the pressure is now on the Government as they had “talked it up” to do the vaccination quickly.

“I was on the Government’s side and I didn’t think we needed to push for vaccination early, considering our global position,” Professor Duckett said.

“But the problem is they’ve announced these deadlines and the public is reasonably saying, ‘You’ve said you were going to start it by now — so how are you going to do it?’.”

Where do I go to get the jab?

Although the Government revealed some detail earlier this month, another unknown is where exactly most Australians will need to go to get the vaccine when the rollout ramps up in late March and April — and when they will be notified it is their turn.

The ABC understands GPs who expressed an interest to be involved in phase 1b of the vaccine rollout — which will be focused on the AstraZeneca vaccine — will be notified if they are required next week.

Professor Duckett said delivery “is a major issue” and the Government would need a minimum of 1 million jabs a week to get close to its deadline of vaccinating all Australians who want one by October.

“Say, for example, you take them [CSL] at their word of manufacturing 1 million doses a week, you’ve still got the issue of getting it into people’s arms,” he said.

“I’m hearing a lot of GPs have put up their hand, which is great, but a lot of them are saying ‘I’d prefer to vaccinate my patients’ [so] they won’t vaccinate many.

“It’s good that they’re doing that, but they won’t be able to do a whole lot of people quickly.”

As part of the process, patients are required to be monitored for 30 minutes after receiving the jab.

Professor Duckett said the “second wave” of GP clinics would likely be a small-scale “but again they might not have space to vaccinate a lot of people quickly”.

And the third groups are GPs setting up actual vaccine super clinics, such as those setting up in their car park, for example.

“But of the three lots, if you have the majority of GPs only wanting to vaccinate their own patients, then you’re not going to hit a million a week.

“The logistics of this are huge.”

Pharmacists are also set to be involved in phase 2a of the rollout flagged to begin from May. The expressions of interest process finished this week.

What about the variants?

The issue of whether COVID-19 vaccines can adapt to the variants of the virus was again brought to the fore this week.

New variants are appearing regularly, and so have new questions about whether COVID-19 vaccines will be able to keep up.

Early evidence suggests it is not an “unknown”, with experts saying the new variants are likely to be covered by existing COVID-19 vaccines — particularly the mRNA vaccines such as Pfizer — though experts say some mutations might slightly blunt the vaccines’ effectiveness.

According to the Westmead Institute’s Tony Cunningham, a vaccine expert of more than 40 years, studies are coming out every week which had “differed a little” on what they found.

“We don’t have good enough data yet,” Professor Cunningham said.

“But if I was addressing a general audience on this matter, I would say there are some strains circulating that are a risk to current vaccine rollouts, yes.

“And they will probably need to be handled but new generation vaccines or boosters to handle these strains should they become widespread.

“But we shouldn’t be alarmed, scientists and vaccine makers are saying they can do this.”

Professor Cunningham said so far Australia had been protected from the variants by its hotel quarantine system.

“And as long as we bottle up the variants it should be OK,” he said.

Oxford University is already working on a tweaked version of the AstraZeneca vaccine to take into account the South African strain, with the newer version expected in the coming months.