The Therapeutic Goods Administration has signed off on the release of 800,000 locally manufactured AstraZeneca vaccines, which might soon help boost the total number of shots delivered in Australia.

So far, Australia's rollout of the vaccine has been slow - due in part to limited supply but also due to the way the system has been set up to deliver vaccines.

But the reality is that to vaccinate the entire population by the target date of October, there'll have to be a serious ramping up soon.

So as today's Coronacast explains, with every passing day, the harder it'll be to reach those targets.

Also on today's show:

* We have a TGA response to (some) questions regarding German research into reports of blood clotting issues surrounding AstraZeneca vaccines

* What we know and what we don't about blood clotting reports