By MERLIN CROSSLEY
Right now we are buying time, to flatten the curve, to prevent our hospitals being overwhelmed by those who have been affected by the explosive spread of this disease. Banning travel and social gatherings and introducing social distancing buys time.
Social distancing is hard in practice. The advice I’ve heard is not to try to imagine you will get the virus, but to imagine you already have it. If you do that, you’ll modify your behaviour more easily, as you think about the risk of infecting your friends and colleagues.
Modifying behaviours buys time, not just for flattening the curve, but for other things: developing faster diagnostics, drug treatments, vaccines, and also for understanding this disease, and for defining at risk groups.
I believe rapid diagnosis will be the game changer. At present the kits test for viral RNA via PCR (that is labs test for the viral genome using a process called the Polymerase Chain Reaction which essentially repeatedly copies a tiny, harmless piece of the genome, until there is enough to detect – if there is no virus then there is nothing to copy so the test is negative). Samples must be transported to a lab and the test takes hours. But imagine if you could instantly test for viral particles on a swab, using a test strip (analogous to a home pregnancy test). Could we test ourselves every day? That would help control this virus. I think this should be possible.
Buying time helps with drug treatments too. There may not be time to develop new drugs from scratch, but researchers and clinicians are trying previously approved drugs to see if they inhibit viral replication or alleviate the symptoms of infection. To me it looks like the kitchen sink is being thrown at this virus but some of the ideas are good.
The big prize is a vaccine. I’m confident that vaccines will be developed, but unsure how effective they will be and how long it will take to deliver them across the world. Even if a vaccine is only partially effective it could help.
As time goes on our understanding of the symptoms and pathology of the disease will improve. This will help with efforts to identify infections early and to treat symptoms. Also, the definition of at risk groups will become clearer. At present it appears that older people are more affected than the young, and men possibly more than women. The more we know about at risk groups, the more easily we can work to protect them.
How much time do we need?
This is the big question. Some people on social media suggest that since the incubation period is mostly less than 14 days, the problem could be solved by a two week lockdown. Well, only if the country’s borders are then closed permanently or closed in synchrony with every other country in the world. China, a country that has effectively contained the spread, is now requiring all incoming passengers to self-isolate in official accommodation for two weeks. This should work but will have multiple broader impacts. I wonder if we will end up being in our own island fortress here in Australia for a while.
Some suggest we only have to wait till the summer because existing human corona viruses are sensitive to heat, so the epidemic will subside as outdoor temperatures rise. The effect of heat and humidity on the new virus is still unknown but to me, unfortunately, it looks like it can spread in the tropics. What’s more, it is facing a population with no pre-existing immunity, so it may have more opportunities to spread than the four common human corona viruses that do tend to burn out in summer. Thus, it may not abate and even if it were to, it might just flip between winters in the northern or southern hemispheres, like the flu.
Nevertheless, postponing epidemics till summer remains a good strategy, as fewer hospital beds are taken up by influenza patients during summer. So, buying time to get closer to summer – which could be done in some northern hemisphere countries – is a good strategy.
This problem won’t be solved quickly. In the long term I see four scenarios: I hope that very rapid detection might help us end the epidemic; treatments could limit the severity of disease; herd immunity via vaccination may be achieved; herd immunity could also be achieved after successive waves of infection led to a majority of the population having been infected – but this is a grim prospect.
It is grim because the numbers are terrifying. But they are less horrifying when one sees them in the context of normal human mortality. In Australia about 160,000 people pass away naturally every year. That is a bit shy of one percent of the population. We don’t really know the mortality rate of this disease because we don’t know how many asymptomatic infections occur. If there are a lot the mortality may be less than one percent.
I’m hoping that not many Australians are infected this year. And I’m hoping researchers will develop rapid testing kits, re-purposed drugs, vaccines, and a clearer understanding of the spread and pathology of the virus.
I’m hoping that people will stop panic buying and will realise that this really isn’t anything like the Black Death or the end of the world! The Black Death carried off around half the population but even then civilisation marched on.
I’m increasingly hopeful. I’m hoping that when this is behind us people will realise that it was not like the First World War – towns, bridges, roads, will not have been destroyed. Instead, the economy will have been paused. It will begin again with a boom and once again the roaring twenties will begin.
After the pause we will have a choice. We can share those strange losses that have come to us, not from destruction, but simply from pausing, or we can let the economic impacts lie where they fell. If we are careful I hope we can share these strange and terrifying economic burdens and avoid ripping the fabric of our wonderful society.
That is a future we can choose but for now let us take social distancing seriously, to help buy time so the expert researchers, clinicians and other workers can do their stuff. Make no mistake this crisis will not be solved by spin, it will be solved by experts in science and medicine, and after that we’ll need first-rate social science and politics to guide the sharing of the load and the restoration and reshaping of our society.
Written by Merlin Crossley, who is working from home. Please note I am not a clinician and am not intending to give medical advice. My first degree was in microbiology and then my doctorate in molecular genetics, so I simply can’t help but be interested in viruses.
Deputy Vice-Chancellor Academic, UNSW
The Crossley Lab blog appears in CMM Friday