Will the White House Correspondents’ dinner be another superspreader?
The answer lies in a kind of math we haven’t typically had to do before.
On Saturday, the White House Correspondents’ dinner will be held in a large ballroom at the Hilton Hotel in Washington, DC. There will be 2,600 guests and several hundred servers and other staff.
Will it be a superspreader?
The amount of risk an event like this carries depends on a number of variables: daily case counts, testing requirements, whether masks will be used, the type of space hosting the event, how recently the average attendee was last vaccinated or boosted, the type of activity taking place, and other random factors, some predictable and others not. These factors determined why the State of the Union Address in March (tests were required, and a few people wore masks) was not a superspreader, while the Gridiron Dinner in April (no tests, no masks, lots of talking, laughing, eating and other “aerosol”-producing activity) clearly was, despite relatively similar daily case counts at the times of the events, and similar demographics in terms of age and vaccination status.
Every configuration is different, but with a little bit of math, a reasonable estimate of how likely a person who is contagious with Covid-19 will be in attendance at an event can be made. For this thought experiment, we’ll assume everyone is using rapid antigen tests.
Given recent case counts in the Washington, DC, metropolitan area, around 20 of the 2,600 guests will have been infected in the week leading up to the White House Correspondents’ dinner. However, because of the same-day testing requirement, we can assume that everyone who has been infected long enough to have become contagious will be detected by the rapid tests. That means that if everyone tested negative on a rapid antigen test right at the door, zero contagious people would be in attendance.
At first.
The problem is that with an event this large and the prevalence of Covid-19 in the DC metropolitan area right now, there’s a reasonable chance that someone will become contagious during the event. These are just the types of folks with superspreader potential, because it is thought that during the early contagious period, viral loads rise incredibly quickly.
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To find out how likely that is to occur, I ran a simple model to stake the odds. I calculated that the likelihood of at least one guest becoming contagious at the White House Correspondents’ dinner is 50.5%. I spoke to my friend Dr. Alyssa Bilinski, a health policy expert and disease modeling whiz. After our conversation, she wrote her own slightly different model—one which is admittedly more elegant and cleaner than mine. But we came up with a similar result; Alyssa’s model stakes the chances of someone becoming contagious during the event at 50.7% (Not bad agreement, but also not good news for the cautious would-be attendees to Saturday’s event.) The figures rise to the mid-50s when we take staff into account, though they’ll likely be masked, and they won’t be eating, laughing, or generally exuding hot air, either literally or figuratively.
In generating our estimates, we both assume under-reporting (i.e., that there are really 4-times the number of cases as reported in public data), that the event lasts 4 hours, that all tests will be done exactly 2 hours prior to the event, and that only rapid tests will be used. If some people use same-day PCR tests, the odds improve. However, if some people use rapid antigen tests in the morning (the testing requirement is “same day,” not “upon arrival”), the odds get worse.
The same math also explains why smallish gatherings like my family’s Passover seder last week were likely safe, sans masks. With 20 people in attendance in San Francisco, and everyone providing a negative test within an hour of the seder, the odds of someone becoming contagious during the event were 0.3%, or 1 in 310 similarly sized seders in SF.
Does the President know and accept the odds of exposure and infection at the event? Does anyone on his team?
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To me, that’s the message. Small events with rapid tests right before? Masks likely add almost nothing. Large events with no tests? Masks, especially good ones, add a lot.
If I were attending this event, and I wanted to decrease my odds of infection, I’d do what many will likely not do: I’d wear an N95 most of the time. While I am personally less worried about what will happen to me if I get infected, I do not want to bring this disease home to my 4-year-old, who remains too young for vaccination. As I recently wrote, if an attendee wears an N95 mask for most of the time that they are in a crowded space (i.e., at all times except when eating), the odds of infection if exposed to a contagious person are a small fraction of what they otherwise might be.
Attending events right now carries some risk. What’s frustrating is that the risks change on a daily basis (#NotEndemic), and they hinge on factors that are unique to each circumstance. In addition, the implications for infection are markedly different, depending on the person. For example, as of now, President Biden is slated to attend the White House Correspondents’ dinner. Sure, he’s vaccinated and boosted. But does the President know and accept the odds of exposure and infection at the event? Does anyone on his team? I doubt it—though, I suppose they do now (I sent this information to the White House earlier today).
With life going on more-and-more normally, though, we need better tools to help people really know their real risks. At the end of the day, taking a risk isn’t inherently a bad thing. Maybe attending the White House Correspondents’ dinner is really important to you. Or maybe it’s a wedding, or a playoff game. But if you’re going to gamble, at least know the odds.
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Photo credit: WASHINGTON, DC - APRIL 28: A view of the venue during the 2018 White House Correspondents' Dinner at Washington Hilton on April 28, 2018 in Washington, DC. (Photo by Tasos Katopodis/Getty Images).
Thanks: Benjy Renton for data acquisition, Dr. Alyssa Bilinski, (as mentioned above), and Zeke Miller for information on the White House Correspondents' Dinner.