Spanish Flu – CHRIS DAEL

The fall Influenza peak in 1918/1919 following a smaller peak in the spring of 1918 (not shown in this graph)

By (Image: courtesy of the National Museum of Health and Medicine) – Pandemic Influenza: The Inside Story. Nicholls H, PLoS Biology Vol. 4/2/2006, e50 https://dx.doi.org/10.1371/journal.pbio.0040050, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1441889

Governor Newsom announced the start of Phase II of California’s COVID-19 response today by allowing limited pick-up service openings for businesses like book stores, sporting goods stores, and florists as early as this coming Friday. This is a measured loosening of restrictions to be sure as there’s no real congregating allowed and this is probably the most that could safely be undertaken at this point. We have not met several of the criteria outlined by infectious disease experts for safe relaxation of stay-at-home orders. In particular, while testing is increasing, we are not at the level where comprehensive evaluation of any symptomatic person can be achieved with results on the same day or within hours. Additionally, it’s not clear that daily new cases are declining let alone for 14 days straight, another of the primary relaxation criteria. Given this, it’s a bit of a risk to begin loosening of restrictions at this point but I’m guessing he hopes allowing these relatively safe activities will help put an end to the incredibly risky behavior of protesters around the state in recent days. Some experts like Dr. Robert Kim-Farley from UCLA are predicting that Phase III which will include the opening of higher risk businesses like movie theaters and gyms might occur sometime in the late summer, possibly August or September. Timelines like this are notoriously difficult to predict however, since they sometimes depend on non-medical decision making by political leaders. I wouldn’t be shocked to see that timeline bumped up somewhat.
It seems pretty clear now that the United States’ COVID-19 disease course is not following a Gaussian curve with an equal slope on the way up to and down from the peak. Instead the disease is declining at a much slower rate than when it ramped up to the peak. This slow tapering recovery will unfortunately lead to significantly more cases and deaths from the initial disease surge than predicted by models that assume a Gaussian distribution as there will ultimately be more area under the curve.

Michael Osterholm, a foremost expert on viruses and pandemics who many people saw for the first time on Joe Rogan’s podcast is the Director of the Center for Infectious Disease Research and Policy (CIDRAP). Last week his group at CIDRAP released a report that describes three possible pandemic wave scenarios based on lessons learned from previous pandemics. The first scenario sees one to two years of recurring peaks and valleys similar to what we’ve just experienced requiring periodic reinstitution of mitigation measures like we’re currently living under. For obvious reasons, this scenario could have dramatic economic repercussions. The second scenario mimics the 1918 influenza pandemic which saw an initial peak in the spring and a massive, much more devastating peak in the fall after relaxation of social distancing measures during the summer. This second peak would almost certainly overwhelm our healthcare system and lead to very large numbers of deaths but would not be followed by significant peaks after the fall peak as the virus would have burned through most of the population. The third scenario describes a slow burn after the current, initial surge. In this scenario there are no peaks and valleys, just a constant relatively stable number of ongoing cases and deaths. This scenario would not require large-scale mitigation measures after the initial peak. While this pattern has not been seen with previous influenza pandemics it could occur with a novel coronavirus such as SARS-CoV-2/COVID-19. Whatever scenario plays out, the CIDRAP group advises that Americans should get used to the idea of significant COVID-19 activity for the next 18-24 months. As the pandemic starts to fade away, it’s likely that SARS-CoV-2 will continue to cause less and less severe illness over the next decade eventually settling in as a non-life threatening upper respiratory infection much like it’s other cold-causing coronavirus cousins.

“The cure can’t be worse than the disease.”

This is a common and somewhat understandable refrain in recent months. Is the damage to the economy caused by public health interventions like social distancing and shelter-in-place worse than the potential damage of COVID-19 itself? Is the cure worse than the disease? How can we know?

“The farther backward you can look, the farther forward you are likely to see.”
Winston Churchill

History can help us if we’re willing to learn from it. Several economists have taken a bite out of this problem with very interesting results. Prof. Emil Verner from the MIT Sloan School of Management along with Dr. Sergio Correia and Dr. Stephan Luck from the Federal Reserve have done what more of us should do–learn from history. Together these economists studied social distancing practices or non-pharmaceutical interventions (NPIs) from the Spanish Flu of 1918 to evaluate the effects of social distancing on the economy. Their paper is not yet peer-reviewed but it provides some compelling insights into the efficacy of public health interventions in a pandemic and the resulting economic impacts.

The 1918 influenza pandemic is thought to have infected nearly a third of the world’s population at the time or 500 million people. In the United States alone, 675,000 people died, worldwide–50 million. It was caused by an H1N1 virus with genes of avian origin. Public health measures at the time were focused on prevention of spread from person to person. Those infected were prevented from breathing the same air as the uninfected. Public health guidelines and interventions at the time included prohibiting mass gatherings, banning non-essential meetings, closing dance halls, bars and cinemas, and some encouraged staggered work times to prevent unnecessary congregation. All pretty familiar stuff today, right? Like today, the degree to which these recommendations were followed varied widely throughout the country.

Policemen in Seattle wearing masks during the 1918 Influenza pandemic/National Archives

What Verner, Correia and Luck found was that, as expected, higher mortality in a region led to greater economic depression. More than that though, they looked at American Cities’ response and compared the economic impact of municipalities who enacted strict social distancing measures with those who enacted much weaker measures. Here they found that cities who enacted the strictest social distancing measures had lower mortality but they also experienced the greatest economic growth. Simply put, cities that were committed to public health measures like social distancing had fewer deaths and better economic outcomes.

The green-dot cities in the upper left who enacted strict NPIs like social distancing over longer periods had lower mortality and higher economic growth whereas the red-dot cities in the lower right, who were more lenient with NPIs, experienced higher mortality and stunted economic growth. The authors say it best.

Comparing cities by the speed and aggressiveness of NPIs, we find that early and forceful NPIs do not worsen the economic downturn. On the contrary, cities that intervened earlier and more aggressively experience a relative increase in manufacturing employment, manufacturing output, and bank assets in 1919, after the end of the pandemic.
Emil Verner, Dr. Sergio Correia and Dr. Stephan Luck/Pandemics Depress the Economy, Public Health Interventions Do Not: Evidence from the 1918 Flu

The economic impacts of this pandemic on families and businesses has been devastating. Public health measures like shelter-in-place and social distancing are a bitter pill to be sure. History tells us, however, that this medicine, while hard to swallow, gives us the best chance of surviving, both medically and economically.

Future generations will study this moment, perhaps as they face their own crisis. Just like us they’ll be looking for clues from the past about how to survive. Will they see ancestors rooted in solid science with an unwavering commitment to public health, or will they see a fleeing from science and reason when things got hard? I’m not sure.

In the end, history will judge.