Welcome to Plugging the Gap (my email newsletter about Covid-19 and its economics). In case you don’t know me, I’m an economist and professor at the University of Toronto. I have written lots of books including, most recently, on Covid-19. You can follow me on Twitter (@joshgans) or subscribe to this email newsletter here. (I am also part of the CDL Rapid Screening Consortium. The views expressed here are my own and should not be taken as representing organisations I work for.)
I really need a haircut. My last one was November on the day before the current extended lockdown in Ontario. This week restrictions were due to be lifted and I have to say that I am in a mood to take on a considerable amount of personal risk to deal with my hair situation. For starters, it is driving my spouse crazy to the point she is now avoiding me. It’s a problem.
But now I have to put on my morbid Covid-19 commentator hat on and ask, is reopening a good idea at this stage? There are many things in favour. First, vaccination rates in Canada will soon be world-beating. Second, cases are plummeting to levels not seen since the beginning of Fall. Third, the weather is warming up. All these factors suggest that the Ontario government’s reopening plan which is based on achieving certain vaccination thresholds is a good one.
However, there is a big problem out there: B.1.617.2. This is the variant that ravaged India last month and is estimated to be 20 to 40% more transmissible than the previous bad variant B.1.1.7 which was already perhaps twice as transmissible as Covid Classic. While vaccines are protective against this variant, with a first dose perhaps only one third are protected from becoming infected. It is hard to know what that might mean for transmission. In the UK, this variant is spreading and will soon be the majority of cases. And Covid cases have started to rise again too — concentrated amongst a younger population.
It is important to recognise that new variants are playing a competitive game against old variants. They spread, not just because they are a coronavirus, but also because they have advantages over other variants. And those advantages come according to, in part, a set of rules we have laid out for them. So if weather is getting warmer, a new variant is going to do better than an old one if it is less susceptible to heat or UV etc. So if there are more vaccinations, a new variant is going to do better if it can still spread despite that. And if people are spending more time outdoors or with better ventilation, a new variant is going to do better if it can spread in those circumstances. In India, there was warmer weather and that is where the variant recently thrived. For many other places, the weather is now just getting warmer.
There is, however, something else I am worried about here. Covid Classic was asymmetric in its spread. Most cases were spread by a few people — so-called superspreaders. For some past epidemics, superspreaders were people who were more socially active than others. For Covid, superspreading is more linked to events. Someone who is highly infectious spends time at an indoor gathering or workplace for a few hours. That puts enough virus into the air that others come into contact with it. This s why we have stopped those events and improved ventilation in workplaces and the like.
So what’s a virus supposed to do? One thing that it could do is increase the set of events that might be superspreading ones. Being able to hang around in the air for longer. Being even more transmissible from infectious people shedding the virus. Getting through masks that are not perfectly fitting. Being able to ‘turnaround’ between infecting someone and replicating quickly for more immediate viral shedding. In other words, superspreading events, being rare, were actually helpful to us once we understood that. What if those are no longer a constraint?
In Melbourne, this week, there is another lockdown as it appears B.1.617.1 (a precursor to B.1.617.2) is spreading. One thing Australia gives us is a much more detailed picture of transmission as they are desperate to hunt down every case and how transmission occurred. The news is worrying.
Mr Weimar said there was evidence of "about four or five" recent cases where the transmission occurred between strangers.
He said venues like the Telstra store in South Melbourne, JMD Grocers & Sweets Epping, a Mickleham display home and Craigieburn Central shopping centre were of most concern to contact tracers.
"They are all examples of transmission with very limited contact," Mr Weimar said.
"With previous variants, we are more used to transmission really occurring in the home, in the workplace ... or those big social settings.
In other words, these are not events but places. People are coming into these places for only a short period of time. Of course, this may just be the same old way of transmission but we just don’t know.
Herein lies the problem: we just don’t know. I feel in many ways we are back to March 2020 and sitting here on the verge of something. If we reopen now we could be making a big mistake and have on our hands a summer outbreak. I don’t know what the probability of that is. But I am not sure anyone does which is my point. This seems like one of those times when having more precaution is warranted despite what anyone might feel about my hair.
I think the place to watch will be the US. Many places have very different vaccination rates and they are mostly open. So we will be able to see just what B.1.617.2 can do. Since we can ‘see’ here in Canada, I suspect we should ‘wait.’