Here are the difficult choices confronting our public health officials 

In a scientific paper published this week by the Imperial College Covid-19 Response Team, 31 researchers from an impressive list of collaborating groups, including the World Health Organization Centre for Infectious Disease Modelling, came up with some stark findings that lay out the extremely difficult choices facing public health officials when it comes to dealing with Covid-19 while there is no vaccine to prevent it or treatment to cure it.

It makes for alarming reading, but it is useful in trying to understand the dilemma confronting our governments.

One option they have is to try to mitigate the spread of the virus, basically trying to slow it down, reduce peak demand on our health care systems, and protect those most at risk from infection – the elderly and those with compromised immune systems. This would mean, among other measures, isolating suspected cases of Covid-19 in their homes along with quarantining people living in the same household, and “social distancing” of everyone who is most at risk from the disease.

The other option, say the researchers, using simulation models from the UK and the US that they say is applicable to other high-income countries, is to try to suppress the growth of the pandemic, and decrease numbers of cases to low levels, a situation that would be maintained indefinitely until such time as a vaccine or cure are available. This would mean, at a minimum, combining a range of drastic measures, including social distancing for the entire population, isolating Covid-19 cases at home, and household quarantine of everyone in the household, as well as closing schools and universities.

To say that neither option is ideal would be the understatement of the year.

The scientists say that mitigating the spread of the SARS-CoV-2 virus might reduce peak healthcare demand by two-thirds and deaths by half. But, they add:

…the resulting mitigated epidemic would still likely result in hundreds of thousands of deaths and health systems (most notably intensive care units) being overwhelmed many times over.

While suppression of the spread of Covid-19, with its “intensive intervention package” seems to be the preferred option — and the one that Nova Scotia and Canadian provinces have opted for — because it would reduce the growth of the pandemic, flatten the curve, and reduce the risk of overwhelming health systems, the Imperial College Covid-19 Response Team finds that it too has a huge disadvantage.

Ferguson et al. conclude that the many and highly disruptive measures needed to suppress the spread of the virus would need to be maintained, or the disease would just come back. They write:

 To avoid a rebound in transmission, these policies will need to be maintained until large stocks of vaccine are available to immunise the population – which could be 18 months or more.

They write that the interventions that are being taken now to suppress the growth of Covid-19, would be “relaxed temporarily” for relatively short periods of time, but that they would have to be re-imposed “if or when case numbers rebound.”

Clearly there are still some very large unknowns, which those making the difficult decisions in our public health agencies must contend with.

The Imperial College Covid-19 Response Team outlines some of the issues officials will need to deal with as the situation evolves:

… there are very large uncertainties around the transmission of this virus, the likely effectiveness of different policies and the extent to which the population spontaneously adopts risk reducing behaviours. This means it is difficult to be definitive about the likely initial duration of measures which will be required, except that it will be several months. Future decisions on when and for how long to relax policies will need to be informed by ongoing surveillance.

Ferguson et al. warn that while short-term suppression seems to have been possible in China and South Korea:

… it remains to be seen whether it is possible long-term, and whether the social and economic costs of the interventions adopted thus far can be reduced.

Still, the researchers conclude:

that epidemic suppression is the only viable strategy at the current time. The social and economic effects of the measures which are needed to achieve this policy goal will be profound.

And:

However, we emphasize that it is not at all certain that suppression will succeed long term; no public health intervention with such disruptive effects on society has been previously attempted for such a long duration of time. How populations and societies will respond remains unclear.

As unsettling as these findings are, the paper is a crucial read for anyone wondering what is happening with the virus, and why our government is taking the measures it is to try to contain the pandemic.