Sweden’s response to the pandemic is different than most countries, and as such has attracted global attention, including in the New York Times, from Thomas Friedman here, and a trio of analysts here. Is Sweden’s alternative to sweeping social distancing a model that could be used by other jurisdictions if it works? In theory, yes in some cases. In reality, not right now in all cases. How about later? Read on.

Sweden is pursuing a policy that might be likened to a deliberately-set forest fire. It acted very quickly–before the virus hit uncontrollable exponential growth–to adopt policies intended to slow the infection rate: it sequestered people likely to be most vulnerable due to age or health issues; it banned gatherings of more than 50 people, constrained select social and business activities, closed some school grades, and then, unlike most countries, Sweden let the rest of the economy remain open, and let most people pursue their daily lives as they wished.  As a close-knit society, they were able to gain consensus as to which activities were most valued economically and then shut down the rest to control the virus.

Sweden’s goal is to let the virus infect most of the healthy younger population quickly, in the hope of achieving a substantial degree of herd immunity within a short period of time, at relatively limited cost to their economy and social fabric. Success depends on three wishes being granted:

1. That the sequestered at-risk population will be effectively protected from infection, despite the prevalence of infection in the rest of the population;
2. That COVID-19 will be much less dangerous to the population left exposed to infection;
3. That infection and recovery will result in significant immunity, such that the society overall will achieve herd immunity.

With herd immunity in place, the sequestered population of vulnerable people could reemerge to a relatively safe environment, with a relatively healthy economy.

This strategy is in contrast to that of most other countries, including Sweden’s immediate neighbors, which have opted to employ pervasive social distancing and other measures to minimize the rate of infections and deaths until vaccines and other treatments arrive to help control the virus.

By choosing to pursue this path so early, Sweden has chosen to take on an unusually high degree of uncertainty and risk. If they made a good bet, they could end up reaching herd immunity with fewer deaths and less economic disruption than if they had followed the same path as their neighbors. However, placing such a bet at a moment of very limited information and high downside risk is equivalent to a gambler coming new to the table and placing a big bet in a game with no idea of the odds.

What are the risks?

1. Perhaps sequestration will fail. Sweden is betting that it can protect the vulnerable, even though there’s a high rate of infection in the population at large. Given how little was known about the virus when they committed to this policy, they are taking on unquantified risk.
2. Perhaps the healthy will die. Based on initial data from China which indicated that the majority of victims were old or had preexisting health issues, Sweden calculated that the fatality rate for people outside those risk groups would be tolerably low. If they are mis-calculated, they’ll be faced with a virtually unstoppable surge of deaths among this group.
3. Perhaps the acquired immunity won’t be good enough. We don’t know yet how much immunity might be conferred on someone who is infected and then recovers from the disease. We don’t know if immunity even exists, and if so, whether it is proportional to the severity of the initial infection, or how long it might last. Sweden is choosing to buy a pig in a poke in this regard. They will pay up front in illness and death, and find out later if they’ve won.
4. Health care system overload. While overall the Swedish health system is ranked #6 in the world by Numbeo, Sweden has one of the lowest ratios of critical care beds-to-population of any developed nation, about 20% as many per capita as the US. If their strategy results in a surge in demand for critical care, as has happened in Italy, Spain, the UK and parts of the US, they could be overwhelmed.  In places where the healthcare system is overwhelmed, fatality rates can be 2 to 14 times greater than that of COVID’s case reported fatality rates. The rise in deaths, sickness, and departures among health care workers further cripples an already overwhelmed system. 
5. Unexpected long-term side effects. When Sweden committed to this path, little was known or even suspected about what damage this virus might do beyond temporary respiratory infection. We now know that it is implicated in strokes and  other clotting issues, kidney failure, heart damage, and other unexpected serious effects. There’s no data yet about what proportion of those who contract the disease and do not die from it will have outcomes that are less than full recovery over the longer term.
6. Lost flexibility. Once committed to this course, it would be very difficult to turn back and regain control of the virus if it were to escape into exponential growth. The UK has tried that, and in some ways is experiencing the worst of both worlds.
7. Liability & isolation. There’s a chance that Sweden will become a super-spreader country, and its decision will increase rates of infection and death across Europe and beyond. Other countries would be very likely to respond by shutting down travel from Sweden, and therefore commerce. Sweden is a small country very intertwined with the European and global economies, and it might end up paying a high price economically despite leaving its domestic economy relatively open.

What are the results so far?

Not surprisingly, Swedes are dying of the disease at a higher rate relative to population than most of their neighbors:  As of May 5^th, Sweden’s deaths-per-million population was 283, which is far worse than its immediate neighbors: 3.4 times higher than Germany’s, 7 times higher than Norway’s, 3.2 times higher than Denmark’s, 6.4 times worse than Finland’s, and 9.6 times higher than Iceland’s. For broader context, it is about the same as the rate in The Netherlands and Ireland, only 2/3 as bad as the rate in the UK, 1.3 times higher than the rate in the US, and 2.6 times higher than the rate in Canada. How does it compare to the world’s gold standards for virus control? Sweden’s deaths-per-million ratio is a whopping 57 times higher than the rate in South Korea, and 69 times the rate in New Zealand.

Sweden didn’t promise a low early death rate, so by their standards they have not yet failed. Although their death rate is high, it is about what they expected. A disproportionate share of deaths have occurred in nursing homes, so they are not entirely protecting vulnerable populations as they had hoped, but nursing homes have been high-risk environments everywhere.

In many ways, Sweden is a naturally socially-distanced country, with very low population densities, even in its cities: Stockholm is only 1/20th as dense as Copenhagen, and 1/60th as dense as Paris. The Swedes compound their low density in the summer, as they spend more time in the countryside, and more time outside in the very long high-latitude days. The real test of Sweden’s gamble will come in the fall, as the population hunkers down indoors for the winter and a likely second wave of the virus circles the globe. If they survive that without a runaway spike in infections and deaths, the next question will be whether herd immunity emerges. If immunity appears in sufficient strength, the elevated rate of early deaths they endured among their younger population may seem like a worthwhile sacrifice. If not, thousands of Swedes will have died in vain.

If this works, is it a good model for other countries or US states?

Sweden will not know if its unconventional policy has succeeded until it determines that the virus is no longer able to spread in its unprotected population. Such resistance, if it appears, could achieve herd immunity as early as late 2020, or possibly not until 2021. Even if they achieve herd immunity, they won’t know how long it lasts until they’ve seen how the population responds to several waves of potential infection. If Sweden determines, sometime in 2021 or later, that it has achieved useful, ongoing herd immunity, and if the net loss of life and economic vitality is less than in countries that chose a “suppression” strategy, and IF such results are clear before there is an effective vaccine (or antiviral cocktail) available, the answer could be yes, but only for countries similar to Sweden in certain critical ways.

Most critically, such countries need to be very early in the infection cycle, before exponential growth is established. Sweden implemented its policies decisively when it had just a tiny handful of cases. As a result, its rate of new infections has so far been kept low enough to protect their healthcare system from overload. Any country that missed that early window, including the U.S. and Brazil, is not in a position to follow Sweden’s example, at least during the first round of infection and suppression. Countries that achieve a very low level of infection after this first wave could consider taking Sweden’s approach going into subsequent viral waves, if they resemble Sweden in these ways:

1. Low density. Worldwide, higher density appears to correlate with higher rates of infection. The UK began down the same path as Sweden, but quickly lost control of the virus in its large, dense urban population, and belatedly switched to a suppression strategy.
2. Social unanimity. Sweden’s citizens were in broad agreement with this policy direction, and have participated well in the voluntary social distancing aspects of it. Countries or states with populations which are polarized on this issue might have a very hard time following Sweden’s lead.
3. Strong border control. Sweden has borders with only two neighbors: Norway and Finland. They are connected to Denmark by a single bridge. The rest is cold salt water. Their neighbors are small-population countries which are practicing strong and effective viral suppression strategies. Countries (let alone states) with limited border controls or neighboring countries that are not controlling the virus would have a hard time emulating Sweden’s policies.
4. High quality heath care system. Sweden, as mentioned above, is ranked 6^th in the world. This gives them confidence to take the risks they are taking.

As for US states, all are far past the point today where they could apply Sweden’s early strategy, so that window is closed. As for the possibility of achieving viral suppression and then turning to the Swedish model for later waves, Individual US states are in a weak position compared to Sweden. They have little influence over their neighbors’ policies, little control over their borders (with the exception of Hawaii, but Hawaii is a major Pacific transit hub and home to a large population of US military service members), and share authority with the federal government, which maintains a monopoly on currency, the military, and many other tools of governance in times of crisis. Moreover, the states have little say in the operation of the health care systems within their jurisdictions.

The outcome of Sweden’s gamble won’t be evident for some time, and the risks they have accepted will remain on the table for the foreseeable future. Regardless of the outcome for Sweden, there are benefits to the rest of the world from being able to learn from Sweden’s gamble. If it does not go well for Sweden, the informational benefits to the rest of the world may be of little comfort to the Swedes.

If efforts to create a vaccine are frustrated well past the current hoped-for release dates in 2021, the number of countries and states that could consider turning to Sweden’s model–if it has worked–will increase. There will be more data about Sweden’s outcomes, more data about how to do a controlled-burn virus cycle, and more data about the other consequences of infection. For now and the foreseeable future, the best response to Sweden’s experiment is to watch, learn, and hope they dodge the worst of the risks they’ve taken on. There’s no country or state in the world today for which it would make sense to try to emulate Sweden in the near term.

Here’s an article that summarizes in layman’s terms the tangle of challenges I think we face, and the path I think we should follow. The author here compares my best guesses about how fast we’ll arrive at a vaccine with those of Bill Gates, who is a little more optimistic than I am. I hope he’s right! Even if he is, we have a lot of work to do before the vaccine arrives.

Here’s the link, from Post Alley: https://www.postalley.org/2020/04/30/timeline-what-we-know-so-far-about-the-virus-and-its-scary/

The early numbers on levels of COVID-19 antibodies found in public samplings are all over the map, and await more rigorous random sampling before they can tell us much about how infectious this virus really is, or about potential immunity. However, there are a few important things we HAVE learned from the early testing for antibodies.

The first is that COVID-19 will be with us for a long time. The Chinese just released a study which indicates we will likely have to contend with recurring waves of the virus until we have medicines and/or vaccines scaled up to match the level of asymptomatic infected people who are unknowingly infecting susceptible people.  In scientific studies, the virus appears to start shedding 2 days after exposure and 1-3 days before symptoms appear, and it continues to shed up to 42 days (highest number I have seen) after symptoms subside.  

Based on modeling the closest relatives to COVID, MERS and SARS, we anticipate approximately 6 waves of the virus over the next 18 months.  We will be having to modulate our economy continuously during this period, as we clamp down to (somewhat) control the virus, then let up to (somewhat) rescue the economy, repeatedly. There will be a lot of hard choices in this period for governments, businesses, institutions, and individuals.  As we increase testing density, our decision making and response will improve.

COVID-19 is the worst pandemic since HIV-AIDS went global in the 1980s, and in certain ways it is already worse. It is quite infectious, can infect from a distance of 6 feet or more, can infect from an asymptomatic carrier, is clearly more fatal than the flu, and may cause long-lasting harm to multiple vital organs. Humans have no immunity to it, and it’s not clear what is required to gain immunity, or how long immunity might last. We have as yet no partial or complete vaccines, and no assurance that we will be able to develop them within any specific time frame, if ever. We have no proven antiviral treatments and no proven immune response management treatments. Under these circumstances, an uncontrolled outbreak can quickly overwhelm health care systems, thereby increasing the death toll.

These are the reasons why scientists urged governments around the world to take the drastic step of imposing a high degree of social distancing on their entire populations, with calamitous consequences for economic activity. Many of our complex just-in-time systems of production and distribution have been degraded, including those necessary to fight this pandemic.

As profound as these consequences are, we would be even worse off without them. Without such drastic reductions in the rate of infection, the virus could kill over 100 million people worldwide in short order, leaving many more with compromised health, and vast social and economic dislocation.

The current shutdown is not sustainable, but fortunately it does not have to be. Once it drives the rate of new infections low enough, we will be able to cautiously restore some degree of economic activity, with a wary eye on the virus’s ability to renew its exponential growth as restrictions are eased.

I believe we must engage in a marathon of changed behavior in order to minimize both the damage to our economies and the damage to our health. The initial social distancing shutdowns, if strong enough, will lower the prevalence of the virus enough for us to be able to control it while partially restoring economic activity. This new reality, of one foot on the gas and one on the brake to maximize economic activity while minimizing health risks, will buy time for all-out efforts to create vaccines to unfold. There’s perhaps a 20-25% chance (my guess) that one of the more than 80 current efforts to develop, test, scale, and deploy a complete or at least strong partial virus in the next two years or less will succeed. Even if that’s true, two years is a long time, and we may need to manage many cycles of virus resurgence and suppression to get through it. In the more likely case that the development of a vaccine takes longer–the average development time for a vaccine has historically been about 13 years–we’ll need to be able to operate our management system for a lot longer. My best guess is about 5 years, with perhaps a 20% chance of twice that long.

To control COVID-19 over this time frame will require that we develop a much better real-time understanding of the state of the battle between us and the virus that causes it. We will need to know, in each city, county, state and country, the level and distribution of active infection, day by day. We’ll need to get very good at increasing and decreasing social distancing at just the right times and in just the right ways. Achieving this will force us to accept some loss, for a while, of personal privacy and personal freedom of movement. It will decimate some sectors of the economy, favor others, and require changed procedures in all. It will drive unprecedented financial support from the Federal Government. Still, we will get better at it, clamping down less severely and less often, for shorter periods of time.As difficult as all this sounds, it’s an option that earlier generations did not have: we are not condemned to relive the 1918 Influenza pandemic, or the Plague pandemic of the mid-14th Century. We can do much, much better, but we must take it very seriously to succeed. We live in a new world now, and we need to work at making it better.