Nicholas A. Christakis Profile picture
Sterling Professor of Social and Natural Science at Yale. Physician. Author of Apollo's Arrow; Blueprint; and Connected. Luckily wed @ErikaChristakis
DLlewellyn Profile picture eileen higgins Profile picture Ross Grayson, MPH, CIH Profile picture Adam Smithee Profile picture LesKatSpr Profile picture 105 added to My Authors
25 Oct
Recently, I’ve come to think we are quite LUCKY, in fact, with COVID-19 – because, although it’s quite transmissible, it could indeed have been much deadlier. There's no reason it couldn’t have been more... Medieval.

Imagine if COVID-19 had been deadlier. Let's talk about it. 1/
Ten months into the pandemic, we know that COVID-19 has an R0 of about 2.5-3.0. That is quite infectious. That’s about twice as transmissible as the seasonal flu, but much less than smallpox or measles. jamanetwork.com/journals/jama/… 2/
We also know quite a bit about how deadly COVID-19 is. The infection fatality rate (IFR – fraction of infected people who die) is 0.5-0.8%; and the case fatality rate (CFR – fraction of people who come to medical attention who die) is about twice that. reader.elsevier.com/reader/sd/pii/… 3/
Read 20 tweets
23 Oct
Some of the ideas and themes of my forthcoming book on the COVID-19 pandemic, APOLLO'S ARROW: THE PROFOUND AND ENDURING IMPACT OF CORONAVIRUS ON THE WAY WE LIVE, bit.ly/apollosarrow which is out on October 27 via @lbsparkbooks, have been sketched by a few essays I've done. 1/
On March 11, an argument in @washingtonpost about how the epidemic virus, while exploiting our social nature, would require the same social nature (including our capacity for cooperation and teaching) to combat it washingtonpost.com/opinions/2020/… (see Chapter 6 of #APOLLOSARROW) 2/
On August 10, an essay in @TheEconomist on innate qualities of SARS-CoV-2 that make it a tricky virus to combat, including its ‘dispersion parameter’ that yields super-spreader events and its asymptomatic transmission economist.com/by-invitation/… (see Chapter 2 of #APOLLOSARROW) 3/
Read 6 tweets
19 Oct
Discoveries are (amazingly enough) still being made in human anatomy. Here, we have new salivary glands: nytimes.com/2020/10/19/hea… Fine reporting by @KatherineJWu
Here we have a discovery from 2013 in the human knee:
Here we have lymphatic vessels in the brain, from 2015:
Read 4 tweets
16 Oct
Here is the current, baroque, racial classification system used by the University of California.

universityofcalifornia.edu/sites/default/…
The arbitrariness of these categories -- including the assignment of people from Djibouti, Sudan, and Somalia to the 'white' category -- should make all involved feel shamed that we have come to this.
And the university imposes a racial hierarchy too! Students can (rightly) indicate that they belong to more than one category, but then: "A student’s primary race/ethnicity is determined by the left-most column in the table above of all the categories selected."
Read 5 tweets
15 Oct
A key to controlling the spread of SARS-CoV-2 is decreasing social mixing, eg, by bans on gatherings. But what about elections? Let’s talk about whether the 2020 primaries changed the course of the COVID19 pandemic and what this might mean for general election on November 3. 1/
Many people are asking if in-person voting is sensible in the middle of a pandemic. COVID19, like any serious outbreak of a contagious disease, can place the virtues of public health and civic engagement into direct conflict. 2/
But we find that the voting that took place in the primaries in the Spring of 2020 had no discernible impact on the course of the COVID19 epidemic in the USA, *at the county level*, as we describe in this essay at @fivethirtyeightfivethirtyeight.com/features/votin… 3/
Read 25 tweets
12 Oct
Extremely sobering new analysis via my colleagues @lhsummers & @Cutler_econ in @JAMA_current concludes that SARS-CoV-2 is a "$16 Trillion Virus" ja.ma/3diC0U9 1/
The economic impact of the COVID-19 pandemic is huge:
1) $200,000 per family; or
2) 90% of a year’s GDP; or
3) 4 times the output loss of the Great Recession; or
4) 2 times the cost of all wars since 9/11; or
5) roughly the cost of climate change in the next 50 years. 2/
About half the 16 trillion dollar [sic] economic impact of COVID is lost GDP, and the other half is the various health consequences. 3/
Read 4 tweets
11 Oct
Let’s talk about the “Swiss cheese model” of combatting the COVID-19 pandemic. This is a classic conceptualization of how to cope with hazards, and it powerfully illustrates several features of what we are facing in the pandemic. #SwissCheeseModel (Image h/t @MackayIM) 1/
What is required to stop the spread of a pathogen like SARS-CoV-2 is achieving some kind of (minimum) threshold level of response sufficient to achieve a deflection in the trajectory of the epidemic, to bring it under control. 2/
A combination of “contact reduction” interventions (eg, school closures, gathering bans) and “transmission reduction” interventions (eg, handwashing, masking) is required. These are “non-pharmaceutical interventions” (NPI), in contrast to things like medicines and vaccines. 3/
Read 14 tweets
2 Oct
POTUS is now reported to have COVID symptoms, which, combined with his other baseline risk factors, is concerning. cnn.com/2020/10/02/pol… Most likely, he will recover, but the medical path is not assured and the political implications are substantial.
POTUS is confirmed to have fever and cough, consistent with *lower* respiratory infection. If hospitalized, this will indicate even greater severity. The coming week will be very indicative of likely path he will take through this serious viral illness.
If he is hospitalized in the coming days (and not simply and truly out of an abundance of caution), POTUS will be facing a roughly 1 in 6 chance of death from COVID19.

If he is intubated, the risk will be higher still.

People to whom he spread the disease may also get sick. 3/
Read 80 tweets
2 Oct
This video, from old work of ours, shows how a respiratory virus spreads across social ties, inexorably, and it illustrates the sort of time course we can expect to occur in a social group like the (mask-less) staff around POTUS. We will hear soon of more cases. 1/
One of the reasons politicians and celebrities contract diseases early in an epidemic, as discussed in #APOLLOSARROW, is precisely that they are often central in social networks, and have many interactions. It's not just that we hear about such people because of their fame. 2/
During past pandemics, including the 1890 and 1918 pandemics, many world leaders contracted infections, as discussed in #APOLLOSARROW (amazon.com/Apollos-Arrow-…). We are seeing this again in 2020, with Johnson, Bolsonaro, and Trump. 3/
Read 6 tweets
21 Sep
Inventing a #COVID19 vaccine is just a first step. For it to make a material difference in the pandemic, we must also manufacture and distribute it, and people must take it (with confidence that it's safe). Let’s talk about the often-overlooked, unsexy problem of DISTRIBUTION. 1/
There are many efforts afoot using diverse biological approaches to develop a vaccine. I think it is likely one will be invented – though how safe and effective it will be, and when it will appear, are still far from certain. 2/
As discussed in #APOLLOSARROW, out on October 27 amazon.com/Apollos-Arrow-…, the many steps necessary before widespread vaccination takes place may mean it does not arrive before we reach herd immunity anyway, in 2022 or so. So a vaccine may not materially shorten the pandemic. 3/
Read 32 tweets
30 Aug
Cool paper by @LHDnets et al shows potential unintended consequences of *inconsistent* #COVID19 NPI policies across jurisdictions.

People moving from place to place can spread #SARSCoV2 to new places as the seek to avoid constraints in their own area. medrxiv.org/content/10.110… 1/
For instance, in March 2020, 10-30% of US churches had increased attendance, even as total number of church visits declined nationally.

People *move* to find open venues, even if it requires long-distance travel. Average distance travelled to churches rose 13% in the period. 2/
Mathematical models reveal that partial measures can often be worse than no measures at all. In the most severe cases, individuals not complying with policies by traveling to neighboring jurisdictions can create epidemics when the outbreak would otherwise have been controlled. 3/
Read 4 tweets
30 Aug
While spontaneous yawning is common across all vertebrate classes, *contagious* yawning is less common and has been observed only in a few species of *social* animals.

But, sweetly, elephants yawn when we do. 1/
A 2018 review of functions of yawning: sciencedirect.com/science/articl…

A 1999 review of *evolution* of yawning: link.springer.com/article/10.100… 2/
Elephants were shown to yawn in 2017. frontiersin.org/articles/10.33… 3/
Read 9 tweets
7 Aug
The selective suspension of this student for posting a photo of a mask-less crowd in a Georgia high school is preposterous and pretextual. The officials should now be ashamed of themselves on two accounts. 1/ cnn.com/2020/08/07/us/…
This effort to suppress bad news about the realities within our our schools as they re-open is evocative of the absurd efforts to do the same for our hospitals at the outset of the COVID19 pandemic. We will not beat this pandemic with denial and lies. theatlantic.com/ideas/archive/… 2/
The truth is a casualty of epidemics, alas, as I discuss (among many other topics) in #ApollosArrow, my new book out in October, on the COVID19 pandemic: amazon.com/Apollos-Arrow-… 3/
Read 5 tweets
16 Jul
Detailed modeling of original Wuhan data in new paper in @nature yields a revised estimate of R0 for SARS-CoV-2 of 3.54 (95% Crl 3.40-3.67) -- on the high end of prior estimates. I had been thinking R0 is 2.6-3.0. nature.com/articles/s4158… This virus is bad. 1/
This figure from the early stages of the SARS-CoV-2 outbreak in Wuhan also shows the way the epidemic was crushed in China, as the Re (effective reproductive rate) was brought down to 1.18 by late January and then down to 0.28 by late February. 2/
Also, study estimates rate of un-ascertained (eg, asymptomatic) cases in Wuhan (previously estimated using travel data as ppl exported cases to the world). Undercount was dramatic; perhaps 16% of cases were actually detected (range 8-23%), despite strong surveillance in Wuhan. 3/
Read 4 tweets
14 Jul
New @PNASNews paper shows that police officers speak with consistently less respect to Black versus White citizens, even after controlling for race of officer, severity of infraction, location of the stop, and even the outcome of the stop. pnas.org/content/114/25… 1/
The dataset consisted of transcribed body camera footage from vehicle stops of White and Black citizens by the Oakland Police Department during April 2014. A total of 981 stops of Black (N=682) and White (N=299) drivers was examined using automated linguistic methods. 2/
Officers in police stops whose conversations were captured with body cameras were much more likely to say "hands on the wheel" to Black citizens and use last names with White citizens, even after controls. Across a range of utterances, the disparity is concerning. 3/ Image
Read 7 tweets
12 Jul
Perfect example of cancel culture — by which I mean 1) forming a mob, to 2) seek to get someone fired (or disproportionately punished), for 3) statements within Overton window. Those doing form-fruste witch burning should be ashamed. ⁦@jonathanchaitnymag.com/intelligencer/…
Here’s another recent example of cancel culture. While this one did not result in the professor being immediately fired, I strongly suspect this took large toll & will reverberate for his career. dailytarheel.com/article/2020/0… The existence of a “Campus Safety Commission” is also noted.
Another example of what is being called “cancel culture,” meeting this definition I think, with preposterous & false charges. reason.com/2020/07/14/gar…

We may add 4) lack of spine by superordinates who simply fear “controversy” and should know better?

via @robbysoave @reason
Read 10 tweets
6 Jul
I want to go on record that it makes no sense to allow sporting competitions (for most sports) to resume in colleges at this time of active COVID19, and especially in those colleges that are otherwise implementing physical distancing for non-athletes. Let's talk about this. 1/
I would hope that universities would show good public health sense and principled consistency. Expediency and dissembling in public health policy-making is bad for our efforts. When we make tough calls, which is inevitable, let's at least be reasoned and honest about it. 2/
Apparently, the @IvyLeague will make an announcement on July 8 about its plans for collegiate sports.

I would hope that only those sports not involving close contact among athletes on the same or opposing teams (eg, golf, tennis, archery, cross-country, etc) will be allowed. 3/
Read 12 tweets
4 Jul
I support removal of many statues (especially those that memorialized actual threats to nation). But I believe that 1) this should be done democratically, not by mobs; 2) statues can often be moved to place for historical context (like Russia did with Stalin statues in Moscow) 1/
Here is the Fallen Monument Park in Moscow, where I have been, as a model: en.m.wikipedia.org/wiki/Fallen_Mo… Statues of confederate generals, etc, should meet this fate. The violent destruction of art and monuments is generally not a sign of a healthy polity. 2/
Another example: in India, many statues of colonists were simply relocated to a distant park. amp.scmp.com/week-asia/life… 3/
Read 5 tweets
2 Jul
I understand the agenda of this @PNASNews opinion piece about how, in the wake of #COVID19, academia may need to think more rationally about gender equity: ow.ly/HqC950AaILs. And I quite understand the evidence of the gendering of household burdens (eg, home schooling) 1/
But I wish that this article had noted the plain fact that men are much more likely to die than women of COVID19, and this is a serious inequity. Death surely harms academic productivity. And male professors will be much more likely to die than women. medrxiv.org/content/10.110… 2/ Image
The average male professor in the USA probably faces twice the risk of death from COVID19 than the average female professor. I cannot understand why this fact was not reflected in this opinion piece (unless I missed it). 3/
Read 4 tweets
28 Jun
Thread of tweets & threads on issue of curation of archives & art, with cases. In general, I think it is best to ADD to record, not SUBTRACT from it. And removing items from display, or making them unavailable, through violent means, is inconsistent with a free & open society. 1/
On what art museums should do when people object to what they see. In short, museums are not obliged to show things, but should not remove them under threat.

2/
Read 9 tweets
25 Jun
Let’s talk about a COVID19 seroprevalence study, this time well conducted (it seems), which provides a petri-dish type natural experiment. It’s the small Austrian mountain ski village of Ischgl, one of the epicenters of SARSCoV2. Thanks to @florianederer for letting me know! 1/
In this Austrian village:
- 1,473 tested (79% of population) in late April, 2020
- 42.4% have SARSCoV2 antibodies (N=625)
- 85% asymptomatic (N=94 symptomatic cases)
- 9 hospitalizations
- 2 deaths
2/
With some calculation, this yields:

IFR = 0.32% (which is very typical of SARSCoV2)

And, given low level of symptomatic cases (perhaps due to young age?),
sCFR = 2.1% (which is very high!) (2/94)

(Most studies show about ~50% asymptomatic cases of COVID19.)
3/
Read 13 tweets