A Few Things We Know About Covid-19


I’ve included some links to sources here. If I’d spent much more time, I’m fairly sure I could source most of these statements well–but I haven’t done so. That means that you’re reading the general impressions of a person without medical expertise, without any formal scientific expertise, and with relatively poor sourcing–the general impressions of a layperson who has spent a fair amount of time following scientists. Please bear that in mind, and use this document as a jumping-off point for further research. At the end of this document, I’ve listed a number of “people to follow”, most of whom have relevant expertise and are much closer to the sources of data than I.

I wrote this document hastily over several hours, with a specific audience in mind. I beg your forgiveness for any factual errors–which are likely, given the haste in which I wrote–and your help in correcting them. Note that I’m assuming a framework of Christian ethics, though I’m hopeful that much of the document will be helpful to some regardless of ethical framework.

There’s the possibility of subsequent edits to this document. I’ll try to document significant changes.

2020-07-04: added a link to this encouraging interview w/ Francis Collins, a public Christian, leader of the Human Genome Project, and current director of the National Institutes of Health.

2020-07-05: added a link to a helpful explanation of how we know that increased case counts are not simply due to increased testing.

2020-07-12: edited to reflect CDC’s update of best estimate of infection fatality rate (estimated percent of those actually infected, not just of those confirmed via testing, who die of the disease), from 0.40% to 0.65%. Also, in that scenario, that 50% of transmission occurs prior to symptom onset.

What are we dealing with?

How bad is it if you get it? 

Most people, especially younger people, are relatively unlikely to experience the most severe symptoms. The CDC estimates a fatality rate somewhere between 0.2% and 1% of those showing symptoms, with a “best estimate” of 0.65%. Other experts see this number as too low. Not included in the “fatality” rate are people who survive and no longer have the virus, but who suffer long-lasting health consequences, ranging from major permanent damage to lungs or other organs, through extreme fatigue lasting for months.

In a group of 500 symptomatic people reflecting the overall population, this implies between 1 and 5 deaths due to Covid-19. Among people older than the overall population, the death rate would be substantially higher. This ignores “survival, but” scenarios. In a population of 300 million, maxing out at 70% infection, the given range implies between 420K and 2.1 million deaths over the course of the disease’s growth.

Haven’t a lot of people already gotten it, and are immune?

No, as far as we can tell. Certainly, a lot of people have had mild cases without ever being tested and being included in confirmed numbers–but best estimates are that they’re still a very small, single-digit percentage of the US population. You may have seen videos from the California doctors who own an urgent-care chain arguing otherwise; their use of statistics was either incompetent or dishonest. Some early studies, using antibody tests that were at the time FDA-approved under “emergency use” without the typical screening for validity, likely substantially over-estimated prevalence of antibodies. We’re still a very long way from the number of immune people that we need for “herd immunity”.

The upshot: most of the population remains vulnerable to Covid-19, and we don’t know much about how long immunity persists after having it–whether it’s more like the common cold or more like chicken pox  in how long immunity lasts. If it’s more like the common cold, there is no substantial herd immunity without an effective vaccine. If it’s more like chicken pox, it will eventually burn through enough of the population, either turning them immune or killing them,  that it can’t easily spread.

Aren’t most of us going to get it eventually anyway?

Besides the “flattening the curve” that you’ve heard about (to avoid overwhelming medical systems), the other advantage of slowing the virus’s spread is that it buys us time–time to discover helpful therapies that keep the worst cases from being so bad, time to develop vaccines that get us to herd immunity without burning through bodies, or time to do both. If we can stay away from exponential growth, (in other words, if every person who gets it infects, on average, less than one new person), the chances of most people not getting it before we have better therapies or vaccines are relatively good. Neither is a certainty, however. One minor note of encouragement is that, among the many vaccine candidates in development, China has recently approved a vaccine for military use. (That particular one doesn’t sound like a good candidate for the general population, with imperfect coverage and frequent side effects.)

(2020-07-04: This interview with Francis Collins, who’s been prominent in science as a Christian for a while and is currently director of the National Institutes of Health, is encouraging and insightful in a various ways, and worth reading. Of relevance here, Dr. Collins notes that at least four vaccine candidates are entering large trials as early as this month, and he’s “guardedly optimistic that by the end of 2020 we will have at least one vaccine that has been proven safe and effective in a large-scale trial”, without taking safety shortcuts. He adds the caveat that we are in uncharted territory.)

Aren’t a lot of deaths being misreported as due to Covid-19?

It’s more likely that deaths due to Covid-19 are under-reported, through people dying at home without testing. Guidelines for reporting Covid-19 as a cause of death are the same as for other diseases, relying on the doctor’s assessment of the causes that actually contributed to a death. You’ve probably also seen rumors of financial incentives for Covid-19 diagnoses. Don’t believe them, but I won’t work to debunk them here.

Another approach is simply to look at how many deaths have been reported in the US over the last few months, compared to typical years–”excess deaths”. There have been far more total deaths than usual, in a pattern roughly corresponding to the lagging effects of lockdowns on deaths. Adam Nisbett has created a helpful graph from CDC data, linked below, to illustrate this. Also, see the FT.com link for some impressive graphs of “excess deaths” around the world.

But isn’t Covid-19 just something like a really bad flu, in terms of deaths? 

This question comes from the comparison of known deaths due to Covid-19 thus far with deaths in a “typical” flu season–for example, comparing the 130K deaths in the US thus far due to Covid-19 with the 20-80K deaths in a typical US flu season.

 This is a really bad comparison, for several reasons–and it leads to far underestimating how bad Covid-19 is, relative to the flu, at a population level. 

First: the typical flu is something that most of us have some immunity to. Even if we haven’t had a specific strain, and even if we become sick, our bodies have some “priming”, from exposure to the various flu viruses around, in learning how to deal with new strains. So, a flu virus has to fight its way through a population that’s already somewhat resistant to it (a level of “herd immunity”), and then, once it finds a host, has to fight its way through that person’s immune defenses, before it can make someone sick–and even as that’s happening, your immune system has a head start on fighting it to minimize the damage.

Now, when a new virus comes around (you may have heard the term “novel coronavirus”), no one’s immune system has seen it before, and they don’t know yet how to fight it. So, the virus can spread easily through a population, and it can invade someone’s body without a lot of initial resistance–and the immune system is left scrambling to catch up.

The seasonal flu happens each year in a context of something close to “herd immunity”, and kills 20-80 thousand per year before “burning out” in the number it manages to  infect and kill. The novel coronavirus is happening in a context of very little herd immunity, and has most of the population to burn through before we get to a death-count number we can compare with the flu. (Note that there are some glimmers of hope in the possibility that some of the other, pre-existing  coronaviruses might offer a bit of help in cross-immunity with SARS-CoV-2–but no certainty whatsoever at this point.)

Next: the seasonal flu number is an estimate, likely substantially inflated. If we looked at known cases, flu deaths would be far lower than the reported 20-80K. So, to make the comparison on the same terms, we’d need to use a very low number of flu deaths, or a much higher estimate of Covid-19 deaths.

Didn’t WHO say asymptomatic spread isn’t common?

No, not really. There was brief confusion, due to someone speaking off the cuff in an interview and spread widely by some sources–but it seems like most spread comes from “pre-symptomatic” people, a few days before they recognize that they have symptoms. This is why the disease is so hard to contain, and why assuming the disease’s presence even if nobody “seems sick” is so essential. The CDC’s best-estimate scenario is that 50% of transmission occurs when people aren’t symptomatic.

But aren’t we seeing Covid-19 backing off (at least locally)?

Well, sort of–but not really. In Reno County in the last few days, we recently went from 13 (IIRC) active cases down to six (due to “recovery”), which is lovely. And then, we added 4 new cases yesterday, and 4 again so far by mid-morning today (2 July). These numbers exclude “probable” cases that KDHE includes.) A substantial fraction of recent cases were from “unknown sources”, which means they got it from someone who had it and wasn’t recognized–which means those people may well have passed it on to others. When it’s circulating in the community, we don’t have a handle on it.

As Dr. Jessie Hawkins (link at end) put it, everything you see is a lagging indicator. Symptoms lag infection and contagion. Doctor visits lag symptoms. Tested cases lag actual cases, because people often don’t get tested until they have symptoms, and the tests take time to come back. Hospitalizations lag tested cases. Deaths lag hospitalizations by quite a bit. And so, lower deaths right now in Kansas than we’ve had at times are the results of actions taken “long ago”, in terms of the disease, to reduce spread. The upward trend in cases in Kansas and the nation is already a lagging indicator of actual cases, and a predictor of hospitalizations and deaths. And no, the increased numbers are not just due to increased testing; the percentage of positive test results is going up in a lot of places, which means that tests are catching a smaller portion of the actual cases than they were catching previously.  (See this article for a great deeper explanation of why that is.)

In counties next door to Reno (see especially Sedgwick), as in the state overall, case counts show unnerving recent patterns that seem likely to lead to substantial growth. And, due to disease spreading multiplicatively rather than additively, numbers can move to entirely different scales (from tens to multiple hundreds) much more quickly than is intuitive. So–no, we’re far from being in a good place to pretend we’ve collectively survived the coronavirus experience. That will continue to be true as long as we have community spread. This doesn’t have to mean life comes to a standstill (see following sections), but it represents the reality of how the virus works.

Nationally, we’ve moved well beyond April’s peak in the number of new cases per day. The graph looks like the start of an exponential growth curve, and hospitalizations, as one would expect, are lagging it by just a bit. This increase in numbers is not simply because of increased testing; the percentage of tests that come back positive has been increasing, indicating that we’re missing more cases than we have in the past. The daily US deaths have trailed off to around 600 per day, which seems like an encouraging direction–but many of those deaths are from illness contracted weeks ago, when there were far fewer cases than there are now.

My impression is that there are some hints that the virus might be decreasing in average severity, but the increases in hospitalizations, tracking with case numbers, are not an encouraging sign.

How should we deal with it?

On lockdowns

After a short phase in the US of encouraging people to “be careful”, much of the US entered some form of “lockdown” or “stay at home order” in an effort to short-circuit the virus and buy time to figure out how to deal with it. The economic and social costs of this, of course, are tremendous, with businesses suffering and closing, layoffs, weddings postponed or shrunken, funerals taken to just a few people, and huge disruption to people’s social habits and even mental health. The lockdowns were costly, and no one is cheering the damage they caused. 

The lockdowns were the equivalent of throwing a train’s emergency brake: deemed necessary to avoid a crash, but damaging to the train, the rails, and possibly the passengers in its own way. They were meant to short-circuit the growth pattern of the virus, so that we could deal with a controlled outbreak rather than a forest fire, and develop the tools to deal with it. Unlike countries such as New Zealand, we didn’t pull it off, and we now have both the negative effects of the lockdown and a forest fire to deal with. It seems unlikely that we will re-enter “stay at home” situations.

Associated costs/harms

There will always be some trade-offs between the costs of experiencing the virus and the costs of managing the virus. The virus hits us directly through its effects on infected people and the secondary effects of consuming medical capacity. And in trying to manage the virus, we also may incur a lot of economic, social, mental-health, and even “spiritual” costs.

The costs are unequally distributed. Many of those earning money or producing goods are not those most likely to suffer the greatest damage from the virus. We can’t completely stop economic production for the long term, or we’ll all suffer greatly. We can’t stop human connection of some sort, or the effects on all will likely be worse than that of the virus. And yet, the core criterion for assessing whether someone is following Christ is whether they “love their neighbor as themself”–which, at a minimum, involves weighting harms to others at least as heavily as one weights harms to oneself.

We won’t get this absolutely “right”–but if we’re followers of Christ, we’ll try to act in wisdom and love.

On managing harms

Some of the disruptions of the last few months have shone helpful light on problems in “normal” life. In many ways, though, most of us wish for much of the “old normal”: for business and personal income to continue, for the ability to visit others or gather with groups “normally”, for weddings, funerals, and graduations to go forward, for the simple rituals of community to resume or continue. People experience great loss in being deprived of these things.

In this case, the medical costs seem especially focused on older or medically vulnerable people. We could eliminate the costs of “loss of normal life” if we simply resumed normal life, ignoring the cost to these groups and some unlucky others–but in so doing, would declare our allegiance to a kingdom that doesn’t have a suffering-servant King. The harms are not only to others individually, but to the validity of the Way of Christian faith, and to the one Christians claim to follow.

Faced with the impossibility of completely “shutting down” indefinitely–a scenario in which everyone suffers greatly, not just a few–we have at least to look for ways that minimize the harms to all. This requires, among other things, that we know what are the things most likely to cause harm, and exploration of ways to meet everyone’s needs while minimizing the harms.

What are the most likely causes of harm?

I’ve already alluded to some of the harms from trying to contain Covid-19: economic pain, feelings of isolation, disruption to normal routines, etc. In this section, I’m looking mostly at the things that are most likely to increase harm from the virus itself, by smoothing its path to new hosts.

The science involving Covid-19 has been happening at a record pace, and as a result, we in the public have seen a lot of changing and “preliminary” information. Add to that the fact that journalists, on average, are notoriously bad at understanding and conveying the content and implications of scientific studies, and it can be hard to keep up with good information. But, here’s a layperson’s understanding of what we currently know–with strong encouragement to go to more-qualified people (listed later) for better information than I can give here.

It seems as though most transmission happens through inhaled respiratory droplets from others, which carry lots of viruses with them from infected people and deposit them into someone else’s respiratory system. This isn’t just bits of phlegm, spittle, or sneeze droplets; one person noted that when you see your breath, you’re seeing respiratory droplets. Since infection depends on the quantity of viral particles one is exposed to, a brief, outdoor interaction with an infected person at a distance is much less likely to result in infection than is an indoor, close-by, extended interaction.

Earlier on, there was substantial concern about the possibility of “fomites”–if I understand correctly, basically the dried-up droplets–depositing virus particles on surfaces, and then the virus being carried to new victims by their touching those surfaces and then touching mouths, etc. My understanding is that this is probably not a major means of transmission, though appropriate caution is still reasonable.

Different people, and different activities, produce different amounts of respiratory droplets, and project them different distances. There are a few things we know to increase the likelihood of infected people passing on the disease to others:

  • Spending extended periods “in the same air” as someone else, regardless of “six-foot” rules. Mixing of room air, along with the duration of exposure, means that sharing a closed indoor space with someone else for an hour will overwhelm the effects of social distancing. Having a lot of circulation of outside air may help somewhat with this. Being outside, with the chance for infectious particles to be quickly blown away, is much better.
  • Being in close proximity. Keeping six feet away from someone minimizes the number of viral particles that move from one person to another in a short time, on average. This is because most droplets tend to fall toward the floor–but it does not eliminate the risk, which increases with time and with what the other person’s doing. (There’s a lot of variation among people in the number of respiratory droplets that they produce in normal speech.)
  • Singing, exercising, or possibly even speaking loudly in an enclosed space. These activities dramatically increase the number of respiratory droplets produced and the distance they may travel. These have been factors in several super-spreading events.
  • Mixing with a lot of people. A person is often most infectious in the several days before they notice symptoms. If they’ve been in potentially infectious situations with three people during that time, they’re probably going to infect fewer people than if they’ve been in similar situations with 50. When one person (or a few) infect a lot of people all at once, this is known as a “super-spreading event”.

Beyond managing transmission, options for managing harm from the virus itself are limited. Once one has it, the disease will, generally, take its course, though medical intervention may help in the more serious cases.

Minimizing harms, maximizing benefits

In the early days of the US’s encounter with the pandemic, the WHO and the CDC discouraged public use of masks. This was, I think, largely driven by the huge shortage of masks for medical personnel–but the messaging was a mistake.

Substantial evidence has accrued for the public use of cloth masks (or any masks other than respirators) as a way to reduce the virus’s spread. They’re far from perfect, and need to be used well and regularly washed, but they’re helpful in keeping anyone who has the virus (remember–lots of people have it and don’t yet know that they do) from passing it on. Remember, most viruses ride out of an infected person’s body on respiratory droplets. And a cloth mask is fairly effective at making those droplets fall to the ground a lot sooner for someone wearing a mask than for someone who isn’t–and there, they won’t be inhaled. A cloth mask doesn’t do much at all to protect the person wearing it, but it does a lot to reduce the risk of their passing on disease to someone else. Indeed, wearing masks may have enough of an effect to enable an otherwise “mostly normal” life and contain the virus’s spread–greatly reducing the harm from disease and the harms of economic and social losses. They may or may not get us fully to disease containment, but they’d let us minimize the costs to all, rather than having to decide who suffers greatly.

Dr. Jennifer Koontz, from Newton, has been offering regular updates regarding the disease, and has an excellent summary of what we currently know about masks, here: https://www.facebook.com/jennifer.koontz.161/posts/10158296214682604

Without widespread use of masks, we’re likely to suffer all the costs the virus wants to demand and the economic and social consequences. This is an inconvenient, but relatively costless, opportunity to love our neighbors in significant ways–or to reject that opportunity.

Beyond this, we need a lot of systemic work to understand where the virus is and how to contain it–but much of that has to be done at a system level, rather than being something that individuals can do.

But masks…

I’ve seen various objections to masks, including violation of personal rights, concern about CO2 buildup, and concern about fungal infections. And, of course, people claiming OSHA authority to discredit cloth masks, and people claiming that cloth masks don’t protect you.

Regarding assertion of one’s right not to wear a mask: I think the precedent and teaching of Christ are clear regarding caring for others, as are the implications of rejecting that teaching. 

Regarding concern about CO2 buildup: there is a small portion of the adult population who shouldn’t wear masks, due to specific health issues. They are joined by young children. For everyone else, cloth masks may be uncomfortable and annoying, but don’t present health issues–and are far less restrictive to air flow than the respirators or masks that many medical professionals or others use for periods much longer than the average person.

Anecdotally, I’ve spent a lot of hours (not during the pandemic) cycling hard in hot weather, wearing a mask with a neoprene shell, carbon filter, and HEPA filter layered together, in “hazardous”-level polluted air, with filters often well-overdue for change–and haven’t experienced the oxygen deprivation that is sometimes claimed as an effect of masks.

Regarding fungal infections: masks should be washed each day you use them, for multiple reasons–including keeping weird stuff from growing. One recommendation I saw stated it simply: treat a mask like you treat your underclothes.

Regarding a post attributed to someone “OSHA-certified” that you may have seen: this post directly contradicts information available on the OSHA website, while citing the writer’s OSHA expertise. This may help in assessing the writer’s credibility.

Regarding the claim that cloth masks don’t protect you–that’s right, mostly; they’re minimally effective at protecting the wearer from incoming germs. That’s not why you wear them–you wear them for the sake of other people, and hope that they have the kindness to do the same for you. Incidentally, this is also why valved masks aren’t good in public; rather than keeping you from passing on your germs, they may actually make them spread further through concentrated, unfiltered airflow on exhalation.

For much more, see the Jennifer Koontz summary that I linked in the “Minimizing harms, maximizing benefits” section.

Some people to follow

Here are a few people with pretty consistently helpful (and generally apolitical) commentary. (Vince Staggs might be an exception to the “apolitical” description, at least by some reckonings, and writes on subjects ranging beyond Covid-19–so skip if you must, but if you do you’ll miss a terrific, intelligent and passionate, perspective on the practical intersection of Christian faith and public life.)

Other helpful resources for churches

The “Reopening the Church” website (https://www.reopeningthechurch.com/) appears to have some terrific resources, including manuals and checklists, for working through processes of decision and implementation regarding re-opening churches (oriented toward churches) and resuming in-person attendance (for individuals), considering both science and faith.

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