Two studies map the future trajectory of the pandemic
By now we know — contrary to false predictions — that the novel coronavirus will be with us for a rather long time.
“Exactly how long remains to be seen,” said Marc Lipsitch, an infectious disease epidemiologist at Harvard’s T H Chan School of Public Health. “It’s going to be a matter of managing it over months to a couple of years. It’s not a matter of getting past the peak, as some people seem to believe.”
A single round of social distancing — closing schools and workplaces, limiting the sizes of gatherings, lockdowns of varying intensities and durations — will not be sufficient in the long term.
In the interest of managing our expectations and governing ourselves accordingly, it might be helpful, for our pandemic state of mind, to envision this predicament — existentially, at least — as a soliton wave: A wave that just keeps rolling and rolling, carrying on under its own power for a great distance.
The Scottish engineer and naval architect John Scott Russell first spotted a soliton in 1834 as it travelled along the Union Canal. He followed on horseback and, as he wrote in his Report on Waves, overtook it rolling along at about eight miles an hour, at thirty feet long and a foot or so in height. “Its height gradually diminished, and after a chase of one or two miles I lost it in the windings of the channel.”
The pandemic wave, similarly, will be with us for the foreseeable future before it diminishes. But, depending on one’s geographic location and the policies in place, it will exhibit variegated dimensions and dynamics travelling through time and space.
“There is an analogy between weather forecasting and disease modelling,” Lipsitch said. Both, he noted, are simple mathematical descriptions of how a system works: drawing upon physics and chemistry in the case of meteorology; and on behaviour, virology and epidemiology in the case of infectious-disease modelling. Of course, he said, “we can’t change the weather.” But we can change the course of the pandemic — with our behaviour, by balancing and coordinating psychological, sociological, economic and political factors.
Lipsitch is a co-author of two recent analysis — one from the Center for Infectious Disease Research and Policy at the University of Minnesota, the other from the Chan School published in Science — that describe a variety of shapes the pandemic wave might take in the coming months.
Scenario No. 1 depicts an initial wave of cases — the current one — followed by a consistently bumpy ride of “peaks and valleys” that will gradually diminish over a year or two.
Scenario No. 2 supposes that the current wave will be followed by a larger “fall peak,” or perhaps a winter peak, with subsequent smaller waves thereafter, similar to what transpired during the 1918-1919 flu pandemic.
Scenario No. 3 shows an intense spring peak followed by a “slow burn” with less-pronounced ups and downs.
A single round of social-distancing will not be sufficient in the long term