National Post (National Edition)
A `No More Waves' strategy for COVID
In our December paper published in the Canadian Medical Association Journal, we argued for a “No More Waves” strategy to follow an immediate period of strong suppression to keep the COVID-19 case count low. Our argument is based on balancing health, economic and social risks. It does not imply a zero-case count, but suggests keeping cases sufficiently low to stop further waves.
Under this model, rather than going through economically costly yo-yos with incremental openings and lockdowns, communities would be able to open on an ongoing basis after an initial, sustained lockdown to suppress the virus and stop the spread. We know Canadians are getting tired of policies encroaching on their freedoms, but avoiding further waves is the best approach to manage health, economic and social risks. Below, we provide a compass to enable the relaxation of health rules and limit the possibility of another wave.
Hospitalization and mortality counts have sadly risen over the past two months. Now we are starting to see some success after governments took actions in December to suppress the spread of the virus. Those restrictions are starting to come off recently, as case counts have dropped. However, it is too early to declare victory. Imported variants have already shown up in Canada, and they are more transmissible and possibly more deadly. Our vaccination program will optimistically lead to herd immunity by the fall, if vaccine delivery and distribution go as planned and vaccines remain effective against the circulating strains. None of this is a slam dunk, and new waves could easily appear beforehand.
That makes our “No More Waves” strategy as relevant today as when we first proposed it before the winter holidays. This strategy includes three basic elements: (i) strengthened enforcement of health interventions to contain transmission; (ii) evidence-based reduction of gatherings based on transmission, social and economic risks; and (iii) ramping up infrastructure required for COVID-19 surveillance, screening and testing (including supporting wide-scale rapid testing) with accompanying contract tracing and isolation.
Compared to the current mitigation strategy, a “No More Waves” strategy would reduce the overall need for prolonged lockdowns and economic, as well as social, hardship. Canada's four Atlantic provinces, which represent roughly seven per cent of Canada's population, originally pursued a maximum suppression strategy that later enabled people to have more freedom of movement without facing health risks. Importantly, the economic and social effects of the pandemic largely reflect the spread of the pandemic. Avoiding the exponential growth of cases, therefore, offers the best opportunity to preserve economic and social activity until vaccinations have been broadly administered.
Although prolonged lockdowns are necessary when the realities of exponential growth have overwhelmed other non-pharmacologic interventions (NPIs), they are unneeded in regions where the incidence has not outstripped public health and health-care capacity. The choice of public health measures is determined by: a) the quality of the test-trace-isolatesupport system; b) the rate of desired decline in cases; and c) the acceptability of the proposed public health measures.
Different NPIs have different predicted effects. Whereas one jurisdiction may choose to go into lockdown for six weeks to drive cases to a low number as quickly as possible, another jurisdiction might choose to close restaurants, bars, fitness facilities and non-essential shopping for 10 weeks to achieve the same effect. The presence of new, highly transmissible variants likely change this calculus, but choosing the interventions should be based on local epidemiology, context and preferences, and should consider the health, economic and social impact of the interventions.
We suggest prioritizing NPIs that are most likely to reduce the spread, while having a lower overall impact on economic and social well-being. Those NPIs that have high economic and social impacts but relatively low effects on transmission should be avoided. For example, we obviously were not going to close grocery and drug stores, given how essential they are, despite some health risk. Similarly, it is our contention that school closures, especially at the primary level, should be considered a last resort.
As transmission falls, further steps can be made to open up economies such as low-density gym, manufacturing and retail business openings. Those interventions that have a large impact on transmission but have relatively small economic and social effects (e.g., universal masking and prohibitions on small indoor gatherings, non-essential travel and mass events), would be preferentially employed.
Like most Canadians, we would like to have mass vaccination programs as soon as possible. We hope that new variants won't stop our progress in containing this woeful pandemic. Until we have medical interventions that predictably work, however, we counsel a “No More Waves” strategy to minimize health, economic and social risks as best as possible.
REDUCE THE OVERALL NEED FOR PROLONGED LOCKDOWNS.