Publi8c Rebellion, Herd Immunity and Prioritizing Super-Spreaders for Vaccines

"Hot-spotting is dramatically more efficient than uniform allocation."

"We conclude that hot-spotting could enable public health authorities to greatly reduce the social and economic costs of COVID-19 until vaccine supply catches up with demand."

New scientific paper

"Let's assume the vaccines do nothing to stop the spread. Removing high-risk individuals doesn't really change anything."

"The optics are not that great: ‘You can get vaccinated because of your bad behaviour' [people taking advantage of an incentive to violate social-distancing rules so they can jump the vaccine queue]."

Mahesh Nagarajan, applied mathematician, business professor, University of British Columbia

Unmasked people take part in a protest against COVID-19 restrictions in Toronto on December 20, 2020. Photo by Chris Helgren/Reuters/File

Not yet published in a peer-reviewed journal, a new research paper recently posted on a 'pre-print' online site lacking independent scrutiny posits that the strategy of 'hot-spotting', essentially recognizing people who present as super-spreaders, with the use of smartphone contact-tracing apps to identify those super-spreaders, and then using the still-scarce supply of vaccines to focus on seeing them as a priority for inoculation, would have the effect of reaching herd immunity levels far faster than with the equal spread of inoculation distribution.

In theory, this would mimic the work of forest firefighters who see a wide-ranging fire and target it for immediate attention for the purpose of stopping its raging spread. In Canada, as elsewhere in an anxious world where the first doses of the recently-approved vaccines produced by Pfizer and Moderna are being circulated, it will take quite a long time -- perhaps into next year's fall season -- before sufficient vaccines will have been produced to facilitate inoculating entire populations against COVID-19.

Until that occurs, society must grapple with the need to self-isolate, to remain vigilant against contagion, to properly mask and attend to hygiene methods in a universal bid to cope with the infectious spread of the coronavirus that has succeeded in short order in upending the global social order in country after country, while threatening food security and taking the world economy into a veritable down-spiralling head-spin. Those doses of precious vaccine are in short order and will be for some time, taxing authorities to dole them out carefully among prioritized groups.

 

Hundreds of people gathered in Montreal Sunday and marched through the city protesting municipal and provincial government restrictions put in place to stop the spread of COVID-19. Montreal police (SPVM) handed out 269 infractions to protesters who weren't wearing masks   CTV News

 

The recommendations out of this paper appear feasible in identifying potential super-spreaders, to then prioritize those who infect the greatest number of other people, for the purpose of vaccinating them and thus removing the threat they represent in the ever-widening arc of infections. Herd immunity would theoretically be accomplished using less than half as much vaccine as opposed to it being distributed more evenly across a population.

Scientists from the Universities of Waterloo and Guelph, working in conjunction with the Perimeter Institute for Theoretical Physics alongside drugmaker Samofi Pasteur were jointly responsible for the content and premise of the paper. Considered an excellent paper by one outside expert, to be seriously considered by Canadian authorities, that expert nonetheless cautioned the protocol would work only should the vaccines be proven to prevent infection with COVID, not merely prevent symptoms of the virus from occurring.

Queen's University infectious-disease specialist Dr.Gerald Evans also commented on the fact that it remains uncertain whether the apps would succeed in identifying possible virus transmitters, or would inadvertently catch "highly mobile persons". The paper was produced through a collaboration between mathematicians and physicists addressing the reality that the vaccine rollout will take considerable time and effort to achieve its ultimate goal. The authors cite theoretical research previously published suggesting targeting potential super-spreaders would have the effect of increasing the effectiveness of a vaccine.

Tracing apps harnessing the Bluetooth function on cellphones warning whether someone has been in close proximity to an individual who has tested positive for COVID to pinpoint those who have an exceptional number and duration of contacts is a vital part of the concept. Mathematical modelling was used to test the possible impact in prioritizing such people as opposed to the effect of uniformly administering vaccine.

 

Up to 2,000 people marched through the streets of Aylmer, Ont., angry about masks and physical distancing rules put in place by the provincial and federal governments. (Kate Dubinski/CBC)

 

They were able to conclude with a degree of confidence that half as many would require shots to reach herd immunity, the point where sufficient numbers of people are vaccinated to make certain the spread has been significantly reduced. Dr. Nagarajan from University of British Columbia points out a possible glitch; while the Pfizer and Moderna vaccines were seen to be 95 percent effective, that effectiveness was based on preventing symptoms; 'protective immunity'. 

The studies failed to collect data on sterilizing immunity, which is to say, whether the vaccines actually act to prevent infection from the virus occurring. Should this not be the case, the method of singling out super-spreaders would fail to be of much help, since they could continue passing on the pathogen to others, Dr.Nagarajan noted. Another issue is the potential  unintended consequences of the strategy, with people seeing an incentive to violate social distancing rules manipulatively to jump the vaccine queue.

 

On Sunday, hundreds of Calgarians marched down Stephen Avenue to protest public health restrictions intended to slow the spread of the coronavirus. (CBC)