COULD THIS BE THE LAST PANDEMIC?
When it comes to novel coronavirus, I don’t know what will happen over the next year any more than you. I can dispense little comfort for the season of boredom and dread that lies ahead. The incredible torrent of coronavirus news items that started arriving late Wednesday and continued through Thursday would shake the nerves of the strongest, most stoical person, i. e., me. But as I write this Friday morning, I try to keep in mind that Canada’s known death toll from the virus is, for the moment, still one.
That figure could by all means be 10,000 by May. But the low death toll, apart from being welcome in itself, puts an upper bound on the likely number of unknown infected now walking around in the general Canadian population. Without testing on a mass scale, we can’t know precisely how many unsurveilled carriers are out there infecting strangers. But if 50,000 of us already had the virus a week ago, we would already be seeing more ill people, and, yes, dead ones who contracted the disease by untraceable means.
There has been a strange shift in the focus of public attention as the disease approaches Canada. When it was still a strictly Chinese crisis, we all boned up on epidemiological ideas like the “basic reproduction number,” denoted as R in math lingo. R represents ° ° the average number of new infections that one case can be expected to create in a non-immunized population.
Each disease, or strain of a disease, has an approximate R that ° is “natural” to it — a propensity for infectivity. The initial R for ° the new virus in China appears to have been between two and three: it is a little more aggressive than regular influenza, but classic infectious menaces like smallpox and polio start at five or higher. Measles is in the teens.
The “zero” in R is important, ° because as a community takes social and political steps to reduce transmission, it can reduce the real- world reproductive number. It becomes no longer “basic” R , but just R for a par° ticular time and place. Reducing R is the goal of the shutdown measures taken with suddenness this week. If the average reproductive number goes below one, you are winning the fight. Mainland China’s extreme communist measures cut it to something like 0.3 or even 0.2.
That means we don’t have to become China to snuff out the virus and spare most of our population. But as case numbers rise in Canada we have become a little distracted by incoming travel- related cases. From a public health standpoint, these cases aren’t especially important. Even their overall number isn’t important. What’s important is whether infections, whatever their origin, are propagating: it’s the rate of reproduction, as everybody seemed to understand a month ago. This is why epidemiologists aren’t crawling over our airports with heat scanners and test kits, and why the value of international travel shutdowns is contested.
That’s not the good news. In 2020, we might fail to drive the reproduction rate of the virus down, and even if we succeed, some people will lose the lottery. Public health officials are right to prepare us for heartbreak and horror.
But I would ask you to consider that this could be the last event of its kind. It could be our Spanish flu — a terrible event destined not to be repeated on anything like the same scale in our lives.
Look at the role DNA sequencing of the coronavirus is already playing: we are already capable of minimizing the reproductive rate of the bug because we can, in a matter of hours and at moderate expense, tell whether a croupy person has coronavirus or seasonal flu. The cost of whole- genome sequencing was in the billions of dollars 20 years ago, and infinity dollars before that. Today, after a Moore’s Law- like march through orders of magnitude, you can get a genome done for under a grand. That implies that we are not likely to be 50 years away from affordable, on-the-spot viral assaying — of a sort that would have allowed China to extinguish coronavirus at the first cough.
I have spoken with people who instinctively envision a future of perpetual viral pandemic — new micro- horrors spilling out of Chinese bat caves and pangolin buttholes with ever- greater frequency until society becomes unrecognizable and distancing becomes semi- permanent. We have mass passenger air travel! And globalization! It’s inevitable! But nothing like Spanish flu ever happened again during a century of globalization overlapping with 70 years of bourgeois- accessible aviation.
And this doesn’t take into account that antiviral drugs are still barely ready for prime time, although the early hope that Gilead Sciences’ experimental remdesivir drug might work on COVID-19 is still alive. Our physiological defences against viral infections are, for now, very much like our ancestors’. Things might be different on that count in 20 years, too.
Snap out of the gloom and it is easy to picture a world in which halting viral pandemics is child’s play — a world in which you bore your grandchildren with tales of the incomprehensible “long spring.” I am more confident we will get there, within what I would call my “lifetime,” if that weren’t tempting fate, than I am about the next 10 weeks.
THERE HAS BEEN A STRANGE SHIFT IN THE FOCUS OF PUBLIC ATT ENTION AS THE DISEASE APPROACHES CANADA.