Dazzle Me with Data, Sway Me with Science!
Using Data Visualization to Explain the Dangers of a COVID-19 Herd Immunity Approach
Let’s face it, Data Overload has teamed up with Math Anxiety. These past six months have been exhausting, but on top of the sickness, death, poverty, and restrictions, I fear the American public is also tired of numbers. COVID-19 has brought us a non-stop onslaught of statistics: infection rates, mortality rates, case-fatality ratios, demographics, and prognostications. Even data enthusiasts like myself now hide under the bed every time we see the Johns Hopkins COVID-19 Dashboard.
From the depths of this informational swamp, the Great Barrington Declaration reared its ugly head.
A Dangerous Permission Structure
The Great Barrington Declaration is an open letter written and signed by three medical professors from Harvard, Oxford, and Stanford. It recommends that only those people at highest risk of dying from the disease isolate themselves to be protected from infection, while the rest of society goes about their business as usual, albeit with “simple hygiene measures, such as hand washing and staying home when sick.” The declaration was sponsored by the American Institute for Economic Research, a libertarian free-market think tank headquartered in western Massachusetts. The institute is part of an organizational network funded by Charles Koch, a far right wing billionaire known for promoting climate change denial and opposing regulations on business.
At first blush, the Declaration sounds intriguing, even if it does sound too good to be true. The authors have impeccable pedigrees from Ivy League institutions in epidemiology and statistical modeling. They describe the burden of never-ending lockdowns, saying, “keeping these measures in place until a vaccine is available will cause irreparable damage, with the underprivileged disproportionately harmed.” Current lockdown policies, the Declaration reads, “are producing devastating effects on short and long-term public health. The results (to name a few) include lower childhood vaccination rates, worsening cardiovascular disease outcomes, fewer cancer screenings and deteriorating mental health — leading to greater excess mortality in years to come, with the working class and younger members of society carrying the heaviest burden.” The Declaration recommends a “focused prevention” approach in which herd immunity is created by letting the disease spread among the less vulnerable population, while simultaneously protecting older, more vulnerable people, presumably by hermetically sealing them in plastic bubbles.
Imagine! Academic doctors from well-respected institutions giving a permission structure to open up the economy and relieve our pain; it sounds fantastic! Why wouldn’t this catch on? Not only has the Declaration been embraced by the White House, but Stanford Nobel Laureate Dr. Michael Levitt has given it his seal of approval, with his own provocative logic and complex statistics. Fifty-two physicians, epidemiologists, social scientists, and biostatistician have cosigned their names, and 10,748 additional medical and public health scientists had signed it online as of October 19, although the true count is unknown, since some of the medical signers included “Dr. Johnny Bananas,” “Dr. Person Fakename,” and “I.P. Freely.”
A Coordinated and Swift Response
If this all sounds too good to be true, it is. The Declaration is downright scary, espousing a fringe viewpoint that would lead to a much higher death toll.
The response to the Declaration from the greater scientific community was swift and scathing. The John Snow Memorandum (named after the “father” of modern epidemiology) was published in The Lancet ten days after the Declaration. The Memorandum was signed by 80 physicians, epidemiologists, and data scientists, followed by 3,600 additional scientific and medical professionals. The Memorandum refuted the herd approach, calling it, “a dangerous fallacy unsupported by scientific evidence.” It warns that, “there is no evidence for lasting protective immunity to SARS-CoV-2 following natural infection, and the endemic transmission that would be the consequence of waning immunity would present a risk to vulnerable populations for the indefinite future.”
Top COVID-19 specialists also weighed in. Dr. Anthony Fauci, director of NIAID, stated that a herd immunity approach was “ridiculous,” “total nonsense,” and “will lead to hospitalizations and deaths.” Dr. Michael Osterholm, the director of the Center for Infectious Disease Research and Policy at the University of Minnesota, called it “pixie dust thinking,” and warned that, “We could expect to see three to four times the number of deaths that we’ve already had in this country if that were to play out.” Dr. Tedros Adhanom Ghebreyesus, Director General of the World Health Organization, called the approach “scientifically and ethically problematic,” and said that “never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic.”
My own back of the envelope calculations confirm the dire outcomes of a “focused protection” approach. If one assumes that 40% of the population would need to be infected with COVID-19 to achieve herd immunity (and this is a lowball estimate), and if one uses the October 19 case fatality rate of 2.7%, there would be up to 131 million cases and 3.6 million deaths. Even if one were to accept the highly unlikely premise of the Declaration that 1) focused protection could keep EVERYONE 65 and older secluded and safe, and 2) long-term immunity would prevent re-infection, we would still have over 644,000 deaths in the U.S., and this would be our BEST CASE scenario.
But presenting one more data table will not convince the American public. Everyone is much too tired of the pandemic, much too tired of economic woes, social distancing, masking, and a never-ending feeling of dread. Anything that promises a panacea but smacks of legitimacy will be too seductive for many to resist.
Convince Me with Context
We don’t need more numbers. We need better data visualization. We need a way to combat the message of, “my data scientist can beat up your data scientist.”
How do we make sure our data messaging is clear, concise, engaging, and on point? Take a horrible counter example below, a chart that shows COVID-19 case fatality rates in the U.S. based on October 15 data.
The chart is accurate and data-driven, but unfortunately it is also dull and misleading. The rapid jump in fatality rate for people over 65 makes it look like everyone under 65 is relatively safe. But what about the 50–64 demographic, which makes up one fifth of the U.S. workforce? They have a 1 in 50 chance of dying from COVID-19, which is pretty damn scary. Even forty-somethings have a 1 in 180 chance of dying, which are not good Vegas odds.
Good data visualization tells a story. Proper use of visual elements, such as charts, graphs, and maps, allows us to make cogent and convincing arguments. Sometimes data visualization requires complex imagery to contextualize large amounts of data (e.g. the Johns Hopkins COVID-19 Dashboard). Other times it requires deceptively simple messaging to push home a single point.
When using data to present an argument to a data-weary audience, I recommend the following:
1) Use only enough numbers to make your point. Nobody is impressed that you did extra credit work. Use numbers as a tool, a weapon, or a guide, but never as a floral centerpiece.
2) Provide relevant context. Find creative ways to tell your audience what a number actually means. Compare your data to something they understand and care about.
3) Give a narrative. Data NEVER explains itself. Use words and stories to guide your audience to the conclusion you want.
4) Show your bonafides. Back up your numbers with proper sourcing, but keep those references in the background. They are there to show you did your homework, just in case you are challenged.
5) Add color. Don’t be afraid to use a little marketing to sell your message.
Imagine you are trying to convince the general public of Indiana (my home state) that the Great Barrington Declaration’s free-for-all, herd immunity approach is dangerous, no matter how tempting it sounds. A poster might look like the following:
The picture needs a good graphic designer with professional tools and better artistic skills to make it publication ready, but the basic elements are all here. It states a clear message (the impact of herd immunity). It establishes assumptions (40% infection rate) and presents consequences (3.6 million dead). It lines up data to make for easier reading and comparison (deaths by age group). It lists relevant references in small print at the bottom. Finally, it provides context for the number of deaths for people under 65, comparing them to the population of cities throughout Indiana.
It’s too soon to tell whether or not this poster will sway anyone’s opinion. Hopefully, however, it will get the general public to stop and think about the greater message, if only long enough to come out from under the bed.