Monday, September 6, 2021

Nature's Way: What COVID-19 might teach us about modern society

"Is it safe?"

The chilling words of Dr. Christian Szell asked as he tortures Thomas Babbington with a dentist drill, wanting to know if it's safe to get his stolen diamonds, in the 1976 film Marathon Man. It's the question many have been asking for over 18 months in the slow torture of the COVID-19 pandemic. Is it safe?

It has never been safe. Disease, accidents, the unexpected wait for us at every turn. Each day we quietly calculate risk to benefit estimates as we engage in a hundred little things. Driving our car to the store (1 in 107 chance of death). Having an alcoholic drink (9-21% increased risk of various cancers). Eating sushi (roughly 1 in 12,500 persons annually, all foodborne illness). Jogging along a highway (3 deaths per 200,000 persons annually). Simply living in a society with a lot of firearms (lifetime odds of assault with a gun 1 in 315, death in mass shooting, 1 in 11,125). 

Risk of death by COVID-19 currently? About 1 in 50, or 2% in Pennsylvania as this is written. A report from Connecticut in August shows the death rate among unvaccinated persons in February 2021 was 20 times that among vaccinated individuals; by August that has closed to 1.68 deaths per 100,000 versus 0.73 deaths/100,000 in unvaccinated versus vaccinated persons, respectively. The 2%? That's based on cases not persons overall. 

From: Cited article in link

So what's this mean?

Back in the spring of 2020, I expected that once SARS-CoV-2 was free to roam worldwide, it would remain in the population indefinitely. Unlike its predecessors, SARS-CoV-1 (case fatality rate 11%) and MERS (CFR 37%), we didn't keep a lid on the virus that causes COVID-19. In the former two events, 2002 and 2012 respectively, governments engaged in rigorous efforts to keep case spread contained. In the case of COVID-19, things got away from us, mostly because of politics--both in China and the US--I'm not picking sides here. Once it was out in the world, it was too late to keep the lid on it. It's now going to be a permanent part of life on planet Earth.

But there's some good news in this, if you want to call it that. Angus Chen, with WBUR in Boston shared this story recently. It echoes what I was thinking more than a year ago, thinking that was based on simple epidemiology: When a new germ invades the human home, it's going to either burn out, be defeated, or operate in the background at a lower level indefinitely, often after some period of intense and deadly activity. Human infectious diseases "burn out" when they kill all of their victims, and they cannot survive in any host other than human. It can be said that killing 100% of victims is not a survival strategy that works well in nature. It's more of theoretical thing than an actual phenomenon. So let's examine the other two.

We defeated smallpox with immunization. Smallpox requires human hosts to survive, and if you immunize almost everyone--as we did in the 20th century--the germ dies out. It was hoped that we would defeat COVID-19 with immunization or herd immunity or medicines, but this has not happened. And before you assume you know where I'm going with this, let me be clear that this isn't about more people getting their shots. I argue that even if we had done so, SARS-CoV-2 was never going to go away.

This is partly because SARS-CoV-2 can also live in other creatures that humans come into contact with. This is true whether one believes it escaped from a lab accident or occurred as a random jump from animals to humans in the wild. It's partly true because of lower immunization rates. It's true because some people can't get immunized, or won't develop immunity because of their genetics (not a lot, but enough). And it's partly true because no matter how many shots people get, immunity isn't going to be perfect. In his interviews with epidemiologists, Chen learns that this is the case, and confirms what I expected. What it means is that we're going to have to learn to live with a little risk.

We do it now, live with risk

At the outset, I shared ways in which common, often enjoyable or useful things pose risks to our survival. We accept those risks because the consequences of not doing so would inhibit our lives in some way. When SARS-CoV-2 led to the disease COVID-19, and people were dying at a high rate, we justifiably freaked out. Coffins piled up in New York...

Photo: LA Times

Hospitals were packed...

Photo: Intermountain Healthcare

If we didn't do something, society might have ended up like Will Smith in the movie Legend.

But even as we reconciled ourselves to the task at hand, we started asking about the costs to the rest of our lives, our mental health, our ability to make a livelihood, our children's education. I asked this in a research article I published in 2020, and I wasn't the only one. We've now reached the point in which we've put out the worst parts of the COVID fire and we're trying to figure out how to deal with an aftermath that will not be what we hoped for--an absence of COVID.

Rather we're going to have to live with it. That doesn't mean living with stacked coffins and exhausted nurses and doctors, however. Living with it is going to mean making realistic estimates of changing risk, risk that's likely to decline over time, and balancing those things society needs to move on to against the risks of causing outbreaks we cannot handle.

Why risk is likely to decline over time

In the news we're led to believe that immunization is the only route to the state of equilibrium I described above. Others resist immunization, preferring to "take my chances" with natural immunity--having the disease and surviving it--or through the use of drugs like ivermectin or Regeneron's antibody treatment. Both are risky strategies. I wouldn't put Regeneron antibody into my body unless I was literally at death's door. I'll take a homeopathic remedy, thank you! (And I did...and I got the shot--at least the shot is more homeopathic than the antibody treatment). Now I don't have room here to sort out everyone's personal risk calculus, so I'll leave it at that.

Thinking about this predicted state of equilibrium, though, we do have to consider the following:

  • Natural immunity from having COVID-19 will contribute to reduced spread, and to reduced likelihood of fatal disease--despite what the CDC and others say about the importance of giving vaccines to people who had and survived COVID-19. 
  • Artificial immunity--vaccination--will also reduce spread and fatal disease rates. 
  • Excessive immunization may buy us some marginal benefits in reduced spread and fatalities, but could also discourage people from getting the shots because repeatedly immunizing people does cause symptoms and suffering. Don't expect this controversy to end for a few years though. It takes time to learn how a vaccine will work and design a plan around that data.
  • The immune system in most people shows that re-exposure to SARS-CoV-2 reactivates latent immunity in memory B- and T-cells. I've written about this elsewhere
  • As more and more of us develop a repertoire of genetic "memory" of SARS-CoV-2, it will become less deadly, and less likely to make us really sick. How much less? That remains to be seen, but it could come to rest at or slightly above the level at which the flu kills people each year. 
  • And most important: these points are all basic immunology, and known virology concerning coronaviruses.
I don't want to over promise here. There are some unknowns, including viral mutations and the base level of virulence of SARS-CoV-2. It does mutate, and it did kill a lot of us. On the other hand, its capacity to mutate isn't limitless and is likely to resemble that found in other viruses in the corona family. Moreover, virulence tends to decrease over time in some infectious agents, especially as a population develops this immune memory I discussed above, and this is virus-specific. For example, we're better at surviving the flu than we were in 1918 (immunized or not), but because of the peculiarities of HIV, without medications, untreated HIV is still almost universally fatal (and there still isn't a vaccine for it). SARS-CoV-2 is likely to skew more toward the flu than HIV, however. 

Time will tell if I'm correct.
Stay safe (enough to still move on with your life!)