COVID-19 and the flu, revisited

COVID-19 isn’t the same as influenza. But the way we end up dealing with it long term may be.

As I’ve noted previously, the Rt number, representing the the average number of people who will become infected by a person infected at time “t”, is falling nearly everywhere in the U.S., due to our nation’s superior access to vaccines. (This is not happening in other parts of the world, though, which will allow the coronavirus to potentially continue to evolve into new variants over time.) Not all Americans are willing to get vaccinated, unfortunately, and it now appears that it’s unlikely we will reach the “herd immunity” numbers (whatever level that might be, since it’s inconsistent from one expert to another) if only vaccinated people are counted. (Since those who’ve already had COVID at least once also have some immunity – though it’s not clear yet how effective that is or how long it lasts compared to a vaccine – some calculations of “herd immunity” include those people, which brings us a lot closer to the typical 70 to 75 percent number.)

But as long as Rt continues to fall and remain low, many of our restrictions should be able to be relaxed or lifted. The risk will remain, especially for those who refuse to get vaccinated, but our social lives could return to something close to normal this summer.

The risk of not reaching “herd immunity,” though, is that there will still be a large number of people who potentially could contract COVID, and particularly an existing or yet-to-emerge variant that is more contagious and possibly more resistant to the existing vaccines. Our therapies for COVID patients have improved, so if there isn’t a huge spike down the road that overwhelms our healthcare system again, COVID could become endemic in a similar way to many viruses that haven’t been eradicated but are largely controlled thanks, in large part, to vaccines. This includes measles, chickenpox, and (in most years) influenza. An annual COVID shot seems likely.

The other similarity between COVID and flu, even now, is the reluctance of people to get a vaccine that promises to protect us from illnesses that, while often mild and annoying, can become serious or even deadly. Historically, only about half of Americans who could get a flu shot each year do so. Nobody likes getting the flu, which can last from hours to days or even weeks. Yet we don’t take the time to get even the partial protection offered by the seasonal flu vaccine. I’m guilty of this myself; for years, I never bothered to get the shot, not because I didn’t believe in the science, but because I didn’t think I really needed it. I was (relatively) young, healthy, and figured I’d just ride out a case of the flu if I got it. There’s a word for that: arrogant. And an even better one: stupid.

Are we absolutely sure that the various vaccines are safe in the long run? That there are no side-effects? Well, no. But I think it’s adorable how many people are suggesting that the vaccines aren’t safe who are still smoking, or overeating, or over-drinking… while also taking other over-the-counter drugs or eating packaged foods without knowing exactly what the ingredients are or how they were manufactured. We have a lot of faith in the production of our food and pharmaceuticals otherwise, and justifiably so. What’s so different about the COVID vaccines? They’re tied up, unfortunately yet inextricably, with our current political civil war.

Update on COVID statistics

A couple of weeks ago I wrote a post that included a lot of maps showing the infections per 100,000 persons throughout the United States. A month ago, on April 1, Michigan was glowing white as the worst state in America for COVID infections:

COVID-19 infections per 100K persons as of April 1, 2021

Here’s where we are a month later, on May 4 (maps from

COVID-19 infections per 100K persons as of May 4, 2021

The Rt number in Michigan is up slightly from April 26, from 0.68 to 0.71, while the Rt number in St. Clair County has fallen to 0.46 from an adjusted 0.54 on April 26. The estimate of those who’ve already had COVID in the county is up to 45 percent, compared to our neighboring counties of Macomb (50%), Sanilac (49%), and Lapeer (38%).

COVID numbers are improving in Michigan

This post relies on data from The map key is here:

I am not an epidemiologist, but I have a life-long fascination with numbers and the relationships between them. As I’ve written before, I’m concerned that both because of the media’s goal to reduce complex ideas to a headline that will get people to click and our collective aversion to those same complex ideas, we’ve missed the point more than once during the pandemic. It’s either a catastrophe or it’s over, depending on which day it is. As is usually the case, the reality is somewhere in between.

Remember last summer, when Michigan was one of the best states in terms of COVID spread? Here’s a map from last August 1:

COVID-19 infections per 100K persons as of August 1, 2020

Dark areas represent counties with very low rates of COVID infections per capita (specifically, per 100,000 persons). The white areas are the places that were experiencing very high rates of infections per capita; at that time it was mostly in the southern tier of the country.

Jump ahead to December:

COVID-19 infections per 100K persons as of December 1, 2020

Nearly every part of the country was experiencing high rates of infection around the holidays. Notable exceptions were Florida and the southern Atlantic coast, northern New England, the Pacific Northwest, and Hawaii. Michigan was hot, except for most of the Upper Peninsula.

COVID-19 infections per 100K persons as of March 1, 2021

By the beginning of March, things were looking pretty good all over the U.S. A slight band of elevated infections from Oklahoma east through Missouri, Kentucky, and West Virginia, but overall quite promising.

Then came April in Michigan:

COVID-19 infections per 100K persons as of April 1, 2021

Suddenly, Michigan was having some of its worst weeks of the pandemic, and if you zoom in, you’ll see that the Thumb region, including my home county of St. Clair, was white hot. We were, unfortunately, the COVID capital of North America for a few weeks.

What caused this flare-up? There are a lot of possibilities: pandemic fatigue has been mentioned numerous times, and does seem likely (though I think it’s safe to say that people in other states are just as tired of the virus as we are in Michigan). I wrote a post recently where I expressed my feeling that we were giving up. Younger Michiganders also got a chance to gather more regularly, particularly as contact sports were allowed to resume in middle- and high-schools. But it’s hard to imagine that these students weren’t gathering prior to the resumption of sports, though perhaps not at the same frequency and without as much intermix between groups from different cities. But it did skew the infection rate among younger people in the state somewhat higher.

The state government didn’t intervene as strongly this time. After the Michigan Supreme Court ruled against Gov. Gretchen Whitmer’s authority to impose restrictions by executive order, perhaps there was a reluctance on the part of her administration to shut things down again. There are also political negotiations on how to spend the relief money the state received from the federal government in the most recent stimulus package, and it may have been necessary to avoid upsetting the Republicans, who control both chambers of the state legislature, as that process continued.

In any case, Michigan, one of the model states for its response to the pandemic last summer, was now the poster child for an out-of-control virus.

At some point, though, I wondered how long that could last. After all, Michigan has rapidly expanded the availability of vaccines since January along with the rest of the country, so a significant number of citizens have had at least one dose of one of the available vaccines by mid-April. And I guessed that quite a few people have already had COVID at this point as well, especially among those who were less compliant with stay-at-home, masking, and social distancing requests. My guess was that, in St. Clair County specifically, about 20 to 25 percent of residents may have already had COVID.

My estimate was far too low. According to the data from, 44 percent of St. Clair County residents have been infected at one point or another during the pandemic:

Percent Ever Infected values for St. Clair County, Michigan

The graph’s upward trend, starting around the holidays, makes sense. Early on, there were few people who’d been infected, making the spread manageable by basic measures like masks and social distancing. During the holidays, more people started to choose to get together with family and friends (though not at a normal rate), allowing the virus to spread to a much broader population. The expanded contact between younger people in mid-March and beyond allowed additional spread.

At this point, then, we’re approaching half of the population in St. Clair County that’s already had COVID. Add to that the expanding number of people who’ve had at least one vaccine shot (or who are already fully vaccinated at this point), and you’d expect the numbers to decline simply because the virus should start to run out of people to infect.

And sure enough, the most recent map bears this out:

COVID-19 infections per 100K persons as of April 24, 2021

We’re not out of the woods yet, but things are trending much better again.

Last spring and summer, there was some coverage of the “basic reproduction number,” or R0, that is the expected number of cases directly generated by one case in a population where all individuals are susceptible to infection. This was the case last summer, when relatively few people had already had COVID and vaccines were still several months away from being available. The number was important because of the health care system being overwhelmed by the early cases, with a lack of ICU beds, ventilators, personal protective equipment (PPE), and other resources. It was critical to reduce that number under 1.0 in order to bring the spread under control and relieve the pressure on our health care infrastructure, not to mention the health care workers themselves.

Now, with the virus having been more widespread, which resulted in large numbers of mostly older Americans dying from COVID-19, and the rollout of vaccines, the more significant number is the “effective reproduction number,” or Rt, which (per is “the average number of people who will become infected by a person infected at time t. If it’s above 1.0, COVID-19 cases will increase in the near future. If it’s below 1.0, COVID-19 cases will decrease in the near future.”

Effective Reproduction Number (Rt) values for St. Clair County, Michigan

St. Clair County reached its highest Rt number (excluding the initial days of the pandemic last spring) on March 5, when it was 1.61. Accordingly, the peak infection rate per capita was on April 2, when it was around 520 cases per 100,000 people in the county. (St. Clair County’s population is around 165,000.) Yesterday, April 24, the Rt number has dropped to 0.50 for the county, its lowest point in the pandemic so far, and it’s trending significantly downward. The number of infections has also dropped, to 101.6 per 100,000 persons as of yesterday.

By comparison, the state of Michigan has similarly seen a decline in the Rt number. After peaking at 1.30 on March 14, the number now stands at 0.68 as of Saturday.

What might this mean? While there are still possibilities for additional infections in the county – and COVID-19 remains serious, especially for older residents who haven’t been vaccinated for whatever reason and for whom the virus is particularly deadly – we appear to be approaching the often-mentioned “herd immunity,” where a large number of people (75% or more is the most common benchmark) have at least some immunity from the virus due to already having survived an infection or through vaccination – or both.

It will be important to continue to encourage those who are hesitant about getting vaccinated (again, for whatever reason) to do so. It’s unlikely that COVID-19 can be completely eradicated, and it seems likely that there will continue to be variants that will require periodic “booster” vaccinations, similar to getting an annual shot against influenza strains. At some point, we will have to determine what level of ongoing infection will be acceptable, and whether we are willing to keep our restrictions in place in order to protect those who have deliberately chosen not to participate in protecting themselves. There are always a small number of people for whom a vaccination may not be possible, due to sincere religious, moral, or medical reasons. But those people are often at risk from infections, including the flu, pneumonia, measles, and now COVID, and they will need to continue to be cautious and we will need to continue to support them by making health care available and affordable.

One last word on efficacy rates and a return to normal

I wrote a lot of words on Thursday about COVID vaccination statistics because I’ve been frustrated that the media – and by extension, the majority of Americans – continue to focus on the potential for more public health and economic distress from the pandemic instead of the positive overall direction we’re headed. It’s understandable, I suppose, since we’ve gone through such a bizarre shared experience and we’re likely always going to be worried that it will happen again.

And it might! I know that the positive impact that the several vaccines are already having doesn’t eliminate the possibility that some variant might still prove resistant to those vaccines, or that something else might happen that takes us back to square one. But what seems likely is a return to normal this summer, provided we understand that eradicating COVID can’t be the requirement for that to happen.

Some media are covering this good news. Vox produced a great seven-minute video that explains what the efficacy rate of the different vaccines really means and why that number isn’t the really important one:

It will be a bit irritating if we reach the so-called “herd immunity” – 70 percent or so of people vaccinated against COVID in the United States – but due to ongoing political and cultural clashes, those of us who’ve been vaccinated will still need to wear masks in public settings to protect those who’ve chosen not to, since it will be possible to be vaccinated but contract the virus, be completely asymptomatic, and spread the virus to those who don’t have protection. That’s why masks and social distancing will probably still be needed this fall, though not at the same level as over the last year.

It is good news, and it’s a credit to rational, science-based thinking, that we’re going to leave the pandemic behind.

A deeper dive into COVID data

I’m taking a deeper dive into some COVID-19 data today. I’m concerned and frustrated that the coverage of the virus has been, and continues to be, too shallow. We’re focusing on things like cumulative numbers of deaths, which has been terrible and significant, certainly. But the real story is much more complex than that, which makes it more difficult to comprehend and results in media stories that focus on things like temporary upticks in positive cases – spring breakers! high school athletes! anti-mask protests! – instead of the generally positive impact that the still-early rollout of vaccines has had already, and what that promises for later this spring and summer.

Overall vaccination numbers are improving

The fact that we have one vaccine for the coronavirus that causes COVID is amazing, though it’s the result of not just months of hard work but years of research into the types of vaccines that are being used, such as the messenger RNA (mRNA) type used in the development of the Moderna and Pfizer/BioNTech vaccines. COVID provided a real-time stress test of the ability to develop such vaccines quickly and safely, and the concept bodes well for future similar viruses in the future.

The COVID-19 pandemic was declared in March 2020, and by the end of the year, we already had vaccines being administered in the U.S. and elsewhere. The pace of vaccinations was painfully slow at first, as supply lines were developed, but has been ramping up significantly over the past several weeks. Specifically, on New Year’s Day 2021, only 22,194 Americans had been fully vaccinated (statistics are all from the Centers for Disease Control and Prevention’s COVID website at unless otherwise noted). As of March 24, 46,365,516 Americans are fully vaccinated, and over 85 million have received at least one dose of the two-dose regimens (myself included). The whole thing is a remarkable achievement and worth feeling very good about.

Hospitalizations have dropped

Around the end of 2020 during the holidays, hospitalization rates rose to a level that hadn’t even been seen during the initial months of the pandemic in March and April. The peak week for COVID-19-related hospitalizations was the week of January 9, 2021. Since then, the number of hospitalizations due to COVID has dropped sharply, as shown in the following chart:

Notice how the numbers haven’t just dropped overall, but the proportions between the different age cohorts have changed as well. Previously, older Americans were being hospitalized at much greater rates than younger people, with about 77% of those in the hospital being 50 or older (and 51% over the age of 65). In the most recent week’s data from March 13, only 69% are 50 or older and only 37% over the age of 65. That’s huge, and likely due to the focus on vaccinating older Americans first after healthcare and other essential workers.

COVID-19 has killed older people almost exclusively

Take a look at these two graphs:

This data includes roughly 408,000 U.S. deaths related to COVID-19, so not everyone who has died so far. But it’s unlikely that the numbers would change much if all of the data were included. Out of over 23 million positive cases of COVID-19 in the CDC’s database, most of them are people between the ages of 18 and 64; in other words, active adults, going to work, maybe not being as careful with social distancing, etc. That’s not surprising, especially when you consider how many K-12 schools went remote during 2020 in response to the pandemic.

But the death rates don’t parallel those case numbers at all. In fact, they’re completely skewed toward older Americans. While those 85 years and older make up only 2.4 percent of the total cases, they resulted in 31.9% of the deaths (and, assuming the case and death numbers come from the same dataset), 23.7 percent of people 85 and older who contracted COVID-19 died.

The same pattern happens all the way down the age cohorts: those aged 75 to 84 made up 4.1% of positive cases, but 27.7% of deaths, and had a death rate of 12.1%; 65-74 were 7.8% of cases but 21.3% of deaths (and a death rate of 4.9%). Compare that to children from infancy to 17 years old: 11.7% of all positive cases, but only around 0.1% of all deaths (and a death rate of 0.01%!).

You can do the rest of the math if you like, but in short, with very few exceptions, the risk of dying from COVID-19 belongs almost completely to those 50 and older, and in particular, those 65 and older. Nearly 81 percent of all deaths have been in that 65+ cohort. Children have almost no chance of dying from COVID-19.

Now, before I get accused of the same kind of insensitivity Texas Lt. Gov. Dan Patrick showed a year ago when he suggested that grandparents were willing to die to save the economy (despite being 69 years old himself), let me point out that I’m in the 50+ cohort and would be more susceptible to a serious case of COVID-19, and so I’ve largely stayed home for much of the last twelve months. COVID-19 is serious… but not to everyone, and treating it as a universal health concern when setting public policy is misinformed at best and pandering to peoples’ fears at worst.

COVID shortened the lifespan of older Americans

This is one of the most contentious claims on social media: Many older Americans have one or more pre-existing conditions that may have contributed to their dying from COVID-19. In other words, it’s difficult to tell whether an elderly person, already suffering from medical issues, actually died from COVID.

While it’s true that many of those who died from COVID-19 in the past year had underlying medical concerns, including previous heart failure (12.5%), chronic kidney disease (16.8%), diabetes (35.7%), obesity (48.5%), hypertension (58.4%), asthma (11.9%), and COPD/emphysema (10.2%), most of those diseases – unless very far long in their progression or when combined with a weakened immune system typical of the elderly – were unlikely to kill someone immediately by themselves. COVID-19 has many far-reaching effects on the human body, but its initial focus is on the cardiopulmonary system, making pre-existing conditions in those parts of the body particularly risky. However, it can’t be assumed that someone with one or more of those conditions (I have three of them myself) was going to die in 2020. I have mild hypertension and had a minor heart attack several years ago and have been overweight for decades (all of which have been significantly alleviated over this pandemic year by losing about 60 pounds), so all in all, I was as likely to die by getting hit by a car while riding my bike as any of my pre-existing conditions.

However, I’m pretty sure that my mother, who died in April 2019 at the age of 79, would not have survived COVID if she’d contracted it last year. She was already very ill from several medical conditions, most significantly renal failure. If she’d somehow held on into 2020 and got COVID, it certainly would have been the last straw. But it would have been difficult to say that’s what she died from, since she was already very ill. It’s like watching someone racing toward a cliff in a car who suddenly floors the accelerator at the last second. You could say “If they just hadn’t sped up at the end…” but believe me, they were going over the edge no matter what at that point. While I’m still sad that Mom died, I’m relieved that my family didn’t have to go through the pain of not being able to visit her or be present when she was in their final days, which we were able to do a year earlier.

An elderly person, with or without one or more medical concerns, is at significant risk of dying if they contract COVID. The statistics bear this out. That’s why it’s been so baffling why so many older Americans continued to support the lack of effort by the previous president and his administration to enforce simple protective measures like masks, social distancing, and temporary restrictions on businesses to keep people – especially themselves! – safer.

Vaccines also reduce the severity of illness from COVID

While it’s not time to go back to normal completely, there are really good reasons to believe that we can do so sooner rather than later. If we continue to vaccinate against COVID-19 at the current rate – or even speed that up – we should reach a point of “herd immunity” sometime this summer. We’ll still need to be cautious at times, especially if you’re in the older age groups that will still be more susceptible to serious illness or death, but the vaccines also appear to significantly reduce the severity of the illness.

Recent reports of “breakthrough” infections from COVID in those who have had vaccines show that the efficacy rate of the various vaccines isn’t perfect. But we knew that from the trial results. A 90 percent efficacy rate means that 10 percent of those in the trial who received the vaccine still contracted COVID. However, the severity of symptoms is reduced, in many cases to the point where those who get COVID after being vaccinated can be described as asymptomatic. If COVID-19 can be reduced to just another mild virus, and one that we can continue to vaccinate against in the future, it no longer will be a major concern in the United States.


The events of the past year are always going to affect those who lived through them, though, much like the generation that lived through World War I and the “Spanish” flu immediately afterwards; the Great Depression; World War II; and other major upheavals in society. We’ll always be looking over our shoulders, waiting for the “next virus” to appear, even if it’s another century before a pandemic of this scale happens again.

Lies, damn lies, and statistics

I confess that my headline is intended to grab a few additional readers, because the topic of today’s post – data – isn’t very sexy. In our alternative facts world, having a bit more respect for actual data would be helpful. But the other end of the spectrum, where “data-driven” becomes an obsession or worse, a shield for making difficult decisions without any accountability (“we just followed the data”), is just as bad. And not understanding what the data actually means is worst of all.

All of these problems existed, and continue to exist, when it comes to the COVID-19 pandemic. A year ago, the federal government basically gave up on trying to compile data on COVID testing, infection rates, and deaths. It was left to a handful of reporters and editors at The Atlantic magazine – all working remotely – to come up with what they called the “COVID Tracking Project.” It became the de facto standard for reporting on the pandemic, so much so that the federal government started using their charts in presentations because they had no similar sources themselves, and it spawned hundreds of imitators at the state and local level. Launched by reporters Robinson Meyer and Alexis C. Madrigal along with editor Erin Kissane and data scientist Jeff Hammerbacher, the COVID Tracking Project eventually added several other Atlantic staff members and others to help compile the massive amount of raw data, make sense of and standardize the different measurements, and figure out how to most clearly and effectively communicate the results graphically. It was an immense undertaking and was also very successful, and frankly we owe these folks a huge thank you for their journalism, which filled a critical need while our national leaders were playing politics with the pandemic response.

The COVID Tracking Project has stopped compiling data and will be shutting down for good later this spring, and Meyer and Madrigal have written a look back at its origins as well as providing a warning that we’re still not getting the pandemic data right even today. It’s worth a read.

Significantly, they point out that the speed of data coming in varies greatly and can be affected by many factors, which need to be considered when making assumptions and reacting to changes in the data. We’re making important decisions about when to reopen (or re-close) schools, retail stores, restaurants and bars, and other public health issues using the data, but those decisions are still reacting to data that isn’t fully understood:

Additionally, as I’ve written about before, there continues to be those who argue that the pandemic won’t be “over” and we can’t go back to “normal” until the COVID-19 virus is completely eradicated. That might happen eventually, though it seems unlikely. What is more likely is that the protection provided by the vaccine will reduce the severity of illness from COVID-19 to not much more than a case of the flu or the “common cold” (some variants of which, interestingly, are also caused by coronaviruses, which leads to some optimism that the mRNA method of developing vaccines might eventually “cure the common cold”). While people do die from the flu, especially in years when the influenza strain is particularly virulent, we don’t shut down society when that happens. Instead, we formulate a new flu shot and hope that most people will bother to get it, which in the past hasn’t been the case. Perhaps moving forward we’ll be more diligent about those other available vaccines as well. Perhaps.

Accurate data is useful. Inaccurate data, data whose origins aren’t understood, or just plain made-up numbers masquerading as data, are useless – yet they’re sometimes used as justifications for questionable decisions. The pandemic has shown us that; it would be nice to think we could learn from our mistakes this time.