Just like we're likely going to be stuck with COVID for the rest of our lives, we're probably also going to be stuck wondering which is the most effective vaccine to protect against it.

Well lucky we've got science to help sort it out, with a new study putting the Moderna and Pfizer vaccines head-to-head across hundreds of thousands of people.

And other scientists have been busy working out how much protection you have against reinfection, if you are infected in the first place.

Also on today's show:

* Quick Fire Friday

* Tegan interrupts Quick Fire Friday with her own - excellent - Quick Fire Question.

As the days tick by since Omicron was discovered, it's slowly spreading around the world.

One example is reports of a couple of Israeli doctors who likely picked up Omicron in the United Kingdom, before flying back home.

Their symptoms are said to be mild at the moment, but more worryingly, both of the doctors were fully vaccinated with Pfizer - that's all three doses.

So what do we know about how Omicron works with our current vaccines?

Also on today's show:

* If we have been vaccinated to recognise the spike protein, why are variants so concerning? Is it the spike that changes?

Nearly two years into the global coronavirus pandemic, it's probably safe to say that we're all pretty much ready for it to be done.

So no wonder we're hoping that very early reports from South Africa are possibly, just maybe, indicating that the Omicron variant is "milder" than variants before.

But how much evidence is there for that yet? Is it true, or just wishful thinking?

Also on today's show:

* Is it possible that the emergence of this variant is actually an encouraging development for the COVID pandemic?

* No big changes yet for Australia's international borders

* The Omicron variant mutation that might end up helping us (a bit)

* In previous episodes you have mentioned that variants can "out compete" other variants. What exactly does this mean and what is the mechanism behind it?

* An update to the Dr Norman Swan Omicronometer of Panic

As the world desperately awaits news from scientists on anything Omicron, some experts have started thinking about where the variant might have come from.

One theory is that it's from someone severely immunocompromised, where the virus has had millions of opportunities to evolve against a poor immune response.

But it's far from the only theory.

So on today's Coronacast, a few other possibilities of where - and when - Omicron might have popped into existence.

Also on today's show:

* The evolutionary lineage of Omicron

* How should Australia be preparing?

* The Dr Norman Swan Omicronometer of Panic is born

It's the news we didn't want: There's a new variant of concern in town and it's got all sorts of mutations just where you don't want them.

It's also got a new fancy name: Omicron, and it's reportedly outpacing Delta in countries in southern Africa.

But is it really? Is it more infectious? Is it more virulent? Is it vaccine resistant, and if so by how much? How much do we really know at the moment? Should I panic?

Also on today's show:

* What if the Omicron variant is the sort epidemiologists expected to see earlier in the pandemic: highly transmissible and less virulent?

As pandemics go, the coronavirus one is pretty big. It rapidly spread around the world, and is still causing problems.

But how does it compare to past pandemics? Are we actually living in a fortunate time in human history?

If we could magically replace COVID with a bug from the past, would it be a good or bad idea? Would you prefer the plague? Syphilis? Perhaps a flu pandemic might tickle your fancy.

Well to help you decide, on today's Coronacast, we go through the pandemics in history.

Also on today's show:

* Rapid antigen tests work well against Delta

* Quick Fire Friday!

All around the country at the moment are family discussions and debates about what to do about that one relative or friend who still doesn't want to get vaccinated.

The numbers of double vaccinated people continue to rise as people realise it's in their benefit to get the jab.

But there will always be holdouts, no matter what policies are put in place.

So how much does it matter if someone at the Christmas party is unvaccinated when nearly 90 percent of us 12 or older are double dosed?

Also on today's show:

* How careful should my vaccinated pregnant daughter be about where she goes and who she sees?

* What's the latest science on viral loads?

When the slew of variants popped into existence last year, scientists began worrying what it could mean for vaccine resistant variants down the line.

So far, the Delta variant has remained top dog. While it is much more infectious than the original coronavirus, thankfully it doesn't evade our vaccines by much.

But what about down the line? As more and more of the world is vaccinated, will the virus find a way to evolve to get around vaccines?

That’s on today’s Coronacast.

Also on today’s show:

* Lockdowns return to Europe

* How is Japan doing such a good job?

* What side effects can I expect from my Pfizer booster shot if I had AstraZeneca for my first and second shot?

As we start to reopen to the world, it's inevitable that we'll start to see more cases of COVID-19 travel over our international and domestic borders.

But it's far from the only bug that will make the journey while travelling inside a human.

Influenza is one viruses we've been largely protected from over the last 18 months, after international border closures put a halt to incoming flights.

So on today's Coronacast, what do we have to keep in mind when reopening and can we protect ourselves and our kids against virus we haven't seen in quite a while.

Also on today's show:

* Will a third dose give me better protection against variants?

* Is there any evidence that taking paracetamol or ibuprofen after vaccination would reduce the body's immune response?