Friends in the US have asked me whether the policies being implemented there to address the Covid-19 epidemic make sense. Specifically, they’re asking for the straight scoop on whether we really need to tank the economy – maybe to the point of economic depression – to deal with this epidemic.
What follows are the main, factual aspects of the situation and policy response that I’ve been able to glean and seem believable to me. (Note: much of this information is available in an excellent albeit slightly technical analysis from experts at the Imperial College of London.)
WHY EPIDEMICS CAN BE TRICKY
If adequately contagious, infectious diseases grow exponentially… and they keep at this until they begin to have a hard time finding people who haven’t yet been infected. The power of this kind of growth is hard for us to grasp because we naturally tend to think in linear growth.
Cases of infection from the virus that causes Covid-19 double roughly every 5 days. At first, this growth seems minor and manageable. But by the time the problem becomes big enough to be worrisome, it’s nearly too late: the problem will be twice as big in a matter of days.
The fundamental nature of epidemics, therefore, poses two interlocking and difficult problems for policymakers. First, to have their maximum effect, policies for managing epidemics need to be implemented while the problem is still relatively small. That’s because the speed of epidemics requires policymakers to aim into the future. Second, policy decisions often have to be made with incomplete information. Waiting to gather all of the data one would like to have is simply not possible.
Takeaway 1. Epidemics get out of hand very quickly, and by their nature they require implementing policies to deal with where things are likely to go, not where they currently are. Policies also often have to be made before we have all the information we’d prefer to have.
WHY IS COVID-19 SO TRICKY?
Not all infectious diseases have the potential to be epidemics. Those that aren’t particularly contagious or aren’t very nasty to those who become infected don’t require the level of attention or concern that Covid-19 demands. So what’s different about this virus?
First, it appears that people who are infected with the virus can transmit to others before they get any symptoms of infection. This makes managing the epidemic much more difficult. If the virus was only transmitted by people who were sick themselves, isolating people who are sick and quarantining their contacts would probably do a good job of putting the breaks on the spread of the virus. But that’s a policy that won’t get the job done with the Covid-19 virus.
Second, the virus is particularly tough on older people. In addition to posing a risk to this group of people, the virus poses a threat to the healthcare system itself. That’s because once people start to get really sick, they can use a lot of healthcare resources: specialized rooms (beds), ventilators, and protective supplies for staff that tend to them. As we will see, it’s concern about the virus’ strain on the healthcare system that is driving most policymakers’ responses.
Takeaway 2. The Covid-19 virus spreads in sneaky ways and can do a lot of damage, both to individuals and to the healthcare system.
DEALING WITH EPIDEMICS: The Basics
Okay, so that’s the landscape. We’re facing a contagious virus that be transmitted by people who don’t even know that they’re infected, and that poses a significant threat to some of the people who become infected and to the healthcare system itself. What can be done?
There are two main strategies for dealing with an epidemic that’s at the stage of Covid-19. The first is to let the infection roll through the population and treat people who become infected. This is called mitigation. The advantage of the mitigation strategy is that it makes the duration of the epidemic short — the damage is done quickly but once enough people have become infected, the virus has no one left to go after and peters out.
The second strategy is to try to slow the epidemic down so that not everyone gets infected or so that infections are spread out over time. This is called suppression. The advantage of the suppression strategy is that at any one time there are fewer people who are sick from the infection. This means that there are more healthcare resources available per sick person at any point in time.
Takeaway 3. The two types of strategies that we could deploy to deal with the Covid-19 epidemic are mitigation and supression. These strategies differ in terms of how cases of infection are spread over time and how long the epidemic lasts.
For the seasonal flu, we generally go with the mitigation strategy. That’s because the healthcare system has the capacity to take care of the sickest folks even when the epidemic hits its peak. We also have vaccines, which are an enormous help. When the vaccines are spot on, the people who are vaccinated are immune to the virus. This is a big deal because, from the virus’ perspective, people who’ve been vaccinated look as though they’ve already been infected, but from the healthcare system’s perspective very few resources were needed to get them to that point.
MANAGING THE COVID-19 EPIDEMIC
Mitigation
There is currently no vaccine for the Covid-19 virus, and it will likely be a year or more until a safe and effective vaccine is available for widespread use. This makes the mitigation strategy less attractive for dealing with Covid-19. But the really big problem (as noted above) is that Covid-19 is both pretty contagious and really tough on older people, and this, in turn, has catastrophic implications for the healthcare system. We simply don’t have enough ventilators, beds, and staff to care for all of the people who will get sick under the mitigation strategy.
And “not enough” doesn’t fully communicate the size of the shortfall in terms of capacity. Even with the most aggressive isolation and quarantine tactics (including requiring people over 70 to practice social distancing), the most recent estimate is that the peak demand for, say, critical care beds will be eight times that of the supply. As a consequence, using the mitigation strategy would lead to something like 1 million people dying from Covid-19… and that excludes deaths from people with non-Covid-19 conditions who wouldn’t receive adequate care because of the buckling of the healthcare system. It would be an almost unthinkable disaster.
Suppression
The suppression strategy is increasingly being put into place in the US: isolating people who are infected, quarantining the people with whom they live, blanket social distancing (i.e., a significant reduction in contacts with people outside of the home), and closing schools & universities. Under this approach, analyses show that there is just enough capacity to deal with the epidemic. Obviously, this will be a blow to the economy… but if implemented well and quickly, it means that the epidemic can be managed from a healthcare standpoint.
The big disadvantage of this strategy is that it must remain in place (perhaps with brief breaks) until a vaccine is available. Once that happens (not 100% certain and definitely several months away at a minimum), we will be able to shift to a mitigation strategy.
So what’s the conclusion at this point? Policymakers have come to the conclusion that the lesser of two evils is the suppression strategy. It will almost certainly cause huge economic disruption but will protect the viability of the healthcare system.
Although some people have argued that stalling out the economy might be worse than breaking the healthcare system (and that is possible), it’s a tough argument to make. The government, for example, can borrow money more quickly and easily than we can create new physicians. And with the healthcare system in tatters, it doesn’t take a lot of imagination to think about the devastating impact of a string of natural disasters or an attack from an enemy might have on the population.
Takeaway 4: Policymakers are choosing the suppression strategy over the mitigation strategy because the death toll and blow to the healthcare system implied by the latter is unacceptable.
SOME SPECULATIVE GLIMMERS OF HOPE
It’s possible that the capacity of the healthcare system can be increased in the intermediate-term (i.e., as the suppression strategy is being used). There are already attempts being made to increase the number of ventilators and to train up current caregivers so they can be deployed to patients who are ill with Covid-19. Also, new therapies may be discovered that reduce the need for ventilators and / or shorten hospital stays. All of these things would help: the greater the effective capacity of the system, the more we can loosen the noose and let more of the virus circulate. That will, in turn, shorten the duration of the epidemic.
It’s also possible that testing can be used to identify people who have antibodies to the virus but are no longer contagious. These people have, in a sense, been vaccinated. The current belief is that people with sufficient antibodies are very unlikely to be reinfected — they will be good to go in terms of working and interacting with people who are ill or who have not yet become infected. I think this strategy is viable, but there have to be enough tests for it to not get in the way of identifying people who are infected and early in the course of their condition. We’re (obviously) not there yet.
Finally, we don’t really know the whole story about this virus. Although our luck has been pretty bad so far, it’s possible that the virus will have a seasonal aspect allowing us to catch our breath as summer comes along. Note that hope isn’t a strategy and that responsible policymakers have to plan without counting on the virus sputtering out as the weather turns warmer.
Takeaway 5: Some things can be done and / or break our way while we await the develoment of a safe and effective Covid-19 vaccine. These include new ways to expand the capacity of the healthcare system, and use of testing to identify those who are suitable to be freed from social distancing efforts. It’s also possible that the virus has a seasonal aspect that will buy us valuable time.
WHAT CAN WE EXPECT?
In the US, current policy choices for managing the Covid-19 virus are mitigation or suppression. For the reasons noted above, mitigation is not viable — too great a loss of life. Also, it’s mission-critical that the suppression strategy is implemented ASAP. Waiting much longer will put the US in the situation of Italy, requiring sheltering in place / near-total lockdowns.
Here’s what we can / should expect in terms of managing the Covid-19 epidemic in the US:
- Isolation of people who have or are suspected of having Covid-19 and home quarantine of house members of those who are infected
- Substantial, social distancing for everyone: work from home, no gatherings, drive-through + delivery of meals but no dining out, restricting movement outside of the home
- Closures of schools and universities*
- Reliance on a stressed but not overwhelmed healthcare system to deal with people who get seriously ill
- Enormous efforts being made to increased the effective capacity of the healthcare system
- Possible use of testing to identify people who have been exposed to the virus and are no longer contagious, and deployment of those people to help restart the economy and keep things moving
- All of the above remains in place (except for brief breaks until the virus begins to spread again) until an effective and safe vaccine is available for widespread use (~18 months)
* Note: Although widespread closing of schools and universities has already occurred, the Imperial College analysis suggests that the negative effects of such closures may approach the benefits.
FINAL TAKEAWAY: For the foreseeable future, we should be prepared to have significantly reduced social contact, targeted isolation and quarantine, and a healthcare system that will at times be operating at full tilt. This new normal will probably last many months at a minimum.
Thank you for the educational yet somber article. Lets pray and hope for the best.