Hello, I'm Michelle Tapper with the Latest From Science.
As restrictions gradually ease around Australia and state borders slowly open
many people are breathing a sigh of relief,
but there are still lots of questions about what the future will look like in
Australia with, or without a COVID vaccine.
And what's the best way to prevent another wave of infection over the
summer months? Joining me today is Professor Raina MacIntyre,
an epidemiologist who leads the biosecurity program at the Kirby Institute.
And she's also a part of a team of scientists advising health authorities.
Hi Raina. Thanks for joining us.
Hi Michelle.
A lot of people are feeling more relaxed than they have in months.
So many people have stopped physically distancing and they've started
hugging again.
Is it okay to ditch the face mask and start hugging friends and family,
if you're in an area like Queensland or Canberra or WA?
You know,
we're still in the middle of a pandemic and it's actually worse today around the
world than it was back in March or April.
So there's always a risk that infection can be reintroduced,
and set off community transmission in Australia.
And depending on what sort of precautions people are taking if that occurs it
kind of determines how severely an epidemic might grow.
So if people are being cautious, keeping their distance, wearing masks,
and generally being careful,
then even if infection is introduced into the community,
hopefully it won't take off as badly.
Now restrictions have slowly eased in Melbourne and we saw some
vision over the weekend of large crowds gathering at the beach.
What would your advice be to people in Melbourne?
So I think, you know,
there's been a lot of hardship that people have had to go through over the last
few months and the gains that have been achieved in disease control through some
pretty draconian measures,
it's really important to hold onto those gains and not to lose them.
There's still, you know, a few cases being diagnosed every day in Victoria.
So if we're not careful,
then we could have another resurgence in Victoria.
So people do need to remember that all that we've got at this stage is the
non-pharmaceutical ways of reducing transmission,
which is keeping your distance, washing your hands, wearing a mask.
So we're definitely not out of the woods and people should still continue taking
these kinds of precautions.
Now we know that President Trump has tested positive to code and a number of
people in his inner circle have also tested positive.
And many of them attended a gathering at the White House where physical
distancing wasn't maintained masks weren't worn,
what can we learn from this?
Well,
it highlights the fact that there's so-called super-spreading events can happen
anywhere anytime,
even in the most privileged of circles.
And, that in the middle of a pandemic,
you really do need to take those precautions, the physical distancing,
the face mask,
particularly in a country like the US where the infection,
there's very widespread community transmission,
and very serious epidemic activity.
And if you don't take those precautions then those kinds of super spreading
events can occur.
So basically don't let your guard down yet.
Now Trump has just been released from hospital and while he was in there he was
treated with a variety of medicines.
What do you know about these treatments and how do they work?
So he was given oxygen for his low blood oxygen levels,
which is the most common treatment for people who need to come to hospital
with COVID-19.
The antibody cocktail that he received,
which is two monoclonal antibodies from a company called Regeneron
is experimental at this stage.
There's no phase three clinical trial data proving that it works,
but there are early phase trial data that do show promising
results that it does decrease the amount of virus in the body,
particularly if you have a high amount of virus to begin with,
and it potentially mitigates the symptoms.
The drug Remdesivir does have phase three clinical
trials, which is the sort of ultimate evidence that we look for,
which is showing protection in people, in human beings,
from the effects of the disease.
And that does show a modest benefit in terms of
making the time to recovery faster.
And it's probably the most promising drug we have so far.
The dexamethazone was a bit unusual. It's an old drug,
it's been around for a very long time. It's a corticosteroid,
which both reduces inflammation,
but also suppresses the immune system and suppresses the
adrenal glands.
The trials of dexamethazone in with COVID-19 have
been really in very sick patients,
people who are generally in ICU,
either with pneumonia or receiving ventilation.
So to see it given to someone who's ambulant, who's walking around,
who's not at that very severe end of the spectrum is
unusual.
And there's obviously the slight concern that it
also does suppress the immune system.
So there has been for treatments over the past seven months.
What about a vaccine? It normally takes about a decade to develop them,
but obviously there's a lot of pressure for an accelerated process here.
How is it possible to do that?
And where are we at with clinical trials with regards to a vaccine?
So whilst the process for vaccine development is accelerated,
it's still going through the same set of steps that every drug or
vaccine needs to go through, which is first of all,
pre-clinical studies and animal studies phase one trials,
phase two trials and phase three efficacy trials.
So all the vaccines are going through that except a couple that have been
given to people in countries like Russia and China without
such data being published. However,
most of the vaccine candidates,
there's many now that have gone through phase one and two trials and several in
phase three trials at the moment.
Now, obviously it's a bit of a million dollar question,
but when do you think that we might likely see a viable
vaccine?
I think it's likely in the first half of next year, in 2021, however,
the supply is the big question.
Even if a vaccine is proven to protect people in a phase three
clinical trial, none of the vaccine technologies have
really the ability to scale up production massively.
So we will expect that supplies will be short initially.
Wealthy countries will probably buy up most of it and other
countries will have to wait in line.
So initially probably the scenario will be that we don't have enough vaccine for
everybody and the first responders, health workers, et cetera,
get vaccinated first.
So, looking into the crystal ball,
the end of 2021 could we see the majority of the world vaccinated or are we
talking a lot longer than that?
I think it'll take longer than that. I mean, you know,
when we talk about the majority of the world, there will be, again,
it's an equity issue.
There is an initiative called COVAX through
CEPI and the WHO,
which is trying to ensure equitable access to a minimum number of doses for all
countries. And many countries have signed up to that, including Australia.
However,
it is true that most countries won't be able to afford or
procure enough vaccine for their whole population very quickly.
So we may see a situation where there remain hotspots of COVID in
low income countries around the world for quite a while,
whilst wealthy countries do manage to get their
populations vaccinated.
And the world health organisation has flagged that a vaccine is not a silver
bullet in our protection against COVID-19. What exactly does this mean?
Yeah. So one possible outcome is that the vaccine
doesn't have a very high efficacy or that, you know,
we don't get a vaccine that has a high enough efficacy.
You need a vaccine that's at least 70 to 80 per cent protective to be
able to achieve herd immunity.
If you've got a vaccine that's only 50% per cent effective,
and many of the trials are powering their trials for expecting 50 per cent
efficacy or around that figure.
You can't achieve herd immunity because you're not able to achieve
immunity in a sufficient proportion of the population with a
vaccine that's only 50 per cent effective. However,
if you've got a vaccine that's low efficacy,
you can still achieve a good outcome if the vaccine reduces the
severity of the disease.
So if the majority of people who get vaccinated have a mild, common,
cold-like infection, instead of a serious life threatening infection,
that's also a good achievement,
but that also means that the virus will continue to circulate. And as I said,
it's likely we'll have hotspots in the world in low income countries.
So is it a case of we're just going to have to live with it, do you think?
It really depends on what kinds of vaccines come out in
the end,
how effective they are and how quickly they can be scaled up and made
accessible worldwide.
So we're about seven months into this pandemic.
What do we know about the long term health effects of COVID-19 on people?
We don't know much, and there's still a lot we don't know about this virus.
We're learning every day, there's new information every day,
but we do know that there seem to be quite substantial, long term effects.
There's chronic fatigue or chronic fatigue syndrome. There's, you know,
people are reporting things like hair loss,
and it's an unknown really how much of these syndromes are due
to microvascular effects.
So we also know that the virus can directly affect the heart muscle,
but also the blood vessels. It can cause heart failure.
It can cause heart attacks, strokes, other vascular syndromes.
And how much of some of these long term effects are caused by vascular
pathology, we don't know.
It is possible that it will turn out to be cardiac or
neurological in nature.
So what would you say to people who have said, 'Look,
it's nothing more than just a common cold and we shouldn't be afraid of it'.
In fact, president Trump had said something along those lines,
what would your response be to that?
Well, I think it's too early to say,
and there could be quite a substantial burden of disease caused by the long term
effects of COVID-19.
And it's far too early to really tell,
all we know at this stage is there does seem to be quite significant long term
effects in a substantial proportion of survivors.
Australia has always said that we're taking a suppression strategy based on
testing and tracing.
Do you think that the testing numbers have gone down though now,
as we seem to relax a little bit and is this a good thing?
Testing numbers have gone down,
but testing numbers are generally a function of how much disease there is in the
community. If you've got lots and lots of disease, but low testing,
then you should be worried,
but if there's hardly any disease around and the test numbers go down,
that's okay.
Really what you need to look at is the ratio of tests to cases.
And finally, what's your advice to people who say,
'we've got this pandemic managed in Australia,
we should just get back to normal'. What would you say?
It depends on what get back to normal means.
If we do have zero community transmission, then yes,
you can do a lot of normal things. However,
the international borders are the major factor.
Closing the international borders is the most important strategy that Australia
has undertaken to achieve the successful status we have today.
If we open the international borders,
then we'll be bringing in infection on a regular basis
and the chance of community transmission will increase substantially.
Yeah, it's obviously a difficult situation to manage Professor Raina MacIntyre,
thanks for your great wisdom and insight, and also for your time.
We appreciate it.
It's a pleasure, Michelle.
And don't forget for regular video updates from the Australian Academy of
Science, make sure to follow us on social media. I'm Michelle Tapper,
see you soon.