Visualizing risk of Johnson & Johnson vaccine side effect

As the Johnson & Johnson vaccine pauses in the United States, Philip Bump for The Washington Post offers a quick visualization that shows 100 vaccinations per second. A red one appears if there’s a side effect. But because the side effect is rare, currently at 1 in 1.1 million, the red dot on the visualization likely never appears as you watch. The blue dots are potential lives saved if the J&J vaccine continues.

I’m reminded of David Spiegelhalter’s video on understanding risk from over a decade ago. So many everyday activities carry risk. The only way we get through the day is not to avoid all risk, which is impossible, but to figure out what risk we’re willing to take.

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Why small gatherings can be dangerous too

A small gathering of 10 people or fewer can seem like a low-risk activity, and at the individual level, it’s lower risk than going to a big birthday party. But when a lot of people everywhere are gathering, small or large, the collective risk goes up. For FiveThirtyEight, Maggie Koerth and Elena Mejía illustrate the reasoning.

The collective part is where many seem to get tripped up. “Flattening the curve” only works when everyone works together. Lower your risk, and you lower the collective risk. You’re helping others. You’re helping those you care about.

Then, collectively, we all get out of this mess.

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Estimate your Covid-19 risk, given location and activities

The microCOVID Project provides a calculator that lets you put in where you are and various activities to estimate your risk:

This is a project to quantitatively estimate the COVID risk to you from your ordinary daily activities. We trawled the scientific literature for data about the likelihood of getting COVID from different situations, and combined the data into a model that people can use. We estimate COVID risk in units of microCOVIDs, where 1 microCOVID = a one-in-a-million chance of getting COVID.

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Illustrations show how to reduce risk at small gatherings

Risk of coronavirus infection changes depending on the amount of contagious particles you breathe in. El Pais illustrated the differences when you take certain measures, namely wearing masks, ventilation, and decreased exposure time.

The suggestions are based on statistical models, so there is more uncertainty than I think the explanations provide, but the sequence of illustrations provides a clear picture of what we can do — if you must do things indoors.

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Minimizing risk

For NYT Opinion, Aaron E. Carroll on doing small things that sum to something bigger:

Too many view protective measures as all or nothing: Either we do everything, or we might as well do none. That’s wrong. Instead, we need to see that all our behavior adds up.

Each decision we make to reduce risk helps. Each time we wear a mask, we’re throwing some safety on the pile. Each time we socialize outside instead of inside, we’re throwing some safety on the pile. Each time we stay six feet away instead of sitting closer together, we’re throwing some safety on the pile. Each time we wash our hands, eat apart and don’t spend time in large gatherings of people, we’re adding to the pile.

A lot of what we do and the choices we make are based on past personal experience. It’s a challenge to look at a dataset that seems beyond us as an individual. So if you’re trying to galvanize a population with numbers, look for all of the ways you could help the individual relate.

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Weighing the risk of moderate alcohol consumption

A research study on mortality and alcohol consumption is making the rounds. Its main conclusion is that all alcohol consumption is bad for you, because of increased risk. David Spiegelhalter, the chair of the Winton Centre for Risk and Evidence Communication, offers a different interpretation of the data:

Let’s consider one drink a day (10g, 1.25 UK units) compared to none, for which the authors estimated an extra 4 (918–914) in 100,000 people would experience a (serious) alcohol-related condition.

That means, to experience one extra problem, 25,000 people need to drink 10g alcohol a day for a year, that’s 3,650g a year each.

To put this in perspective, a standard 70cl bottle of gin contains 224 g of alcohol, so 3,650g a year is equivalent to around 16 bottles of gin per person. That’s a total of 400,000 bottles of gin among 25,000 people, being associated with one extra health problem. Which indicates a rather low level of harm in these occasional drinkers.


The paper argues that their conclusions should lead public health bodies “to consider recommendations for abstention”.

But claiming there is no ‘safe’ level does not seem an argument for abstention. There is no safe level of driving, but government do not recommend that people avoid driving.

Come to think of it, there is no safe level of living, but nobody would recommend abstention.


See also Spiegelhalter talk about weighing risk against benefits in a video from 2010.

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