COVID Transmissions for 3-10-2021
It's not "COVID Arm," and it's also harmless
Good morning and welcome to COVID Transmissions.
It has been 478 days since the first documented human case of COVID-19. In 478 CE, the first Shinto shrines were built in Japan. 478 also happens to be the area code for Macon, Georgia, but that seems significantly less important.
Today I cover a story about a relatively rare delayed vaccine reaction that is absolutely harmless. Also, I advertise a public educational event that I think you all may find interesting.
As usual, bolded terms are linked to the running newsletter glossary.
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Now, let’s talk COVID.
“COVID Arm” isn’t anything to be worried about
Some months ago, there were reports that people were experiencing rashes—actually, most often young people—after receiving a dose of the Moderna COVID-19 vaccine: https://www.usatoday.com/story/news/health/2021/01/27/covid-arm-moderna-vaccine-rash-harmless-side-effect-doctors-say/4277725001/
At the time, as now, it was emphasized that these rashes were harmless. For some reason, they got the name “COVID Arm” at that point, even though they are not a symptom of COVID-19 in any way.
Headlines about “COVID Arm” have started to reappear today because of a letter in the New England Journal of Medicine, where several authors explore this harmless vaccine reaction and note that they think it is a T cell-mediated, or a “delayed-type hypersensitivity reaction,” which refers to this sort of delayed reaction that occurs from the activities of immune cells. They present evidence of this from a case series of 12 patients—not many—but they’ve certainly provided an interesting and testable explanation for this harmless phenomenon.
In fact, the phenomenon is so harmless that it forms the basis of several medical tests. The most common is the TB test, which relies on providing an immune insult that will attract cells that react to M. tuberculosis antigens. If you have such cells, due to having been exposed to M. tuberculosis, they will react to the immune insult and produce a delayed-type hypersensitivity reaction. Since the reaction is harmless, it’s a useful way to detect if a person may have tuberculosis.
I’m mostly calling this out because the headlines I’ve seen today have kind of buried the lede on this—that this reaction is HARMLESS—but I also think the mechanism is very interesting!
Check out the NEJM letter here: https://www.nejm.org/doi/full/10.1056/NEJMc2102131
Public event: understanding virus transmission
My (undergrad) alma mater, Caltech, is doing a public event on March 15th where some graduate students are going to talk about virus transmission dynamics with a PR office moderator from the Institute. I think it’ll be interesting, so I’m passing the link along to all of you: https://www.caltech.edu/campus-life-events/master-calendar/conversations-on-covid-19-understanding-viral-transmission-89933
It appears to be free, but please note two things. One, the time zone is Pacific daylight time, because the clocks will change on March 14th and Caltech gets its “Cal” from “California.” Two, while it’s listed as a public event, the registration asks what your affiliation with Caltech is, and doesn’t seem to have a field for people who heard about the event but aren’t from the local Pasadena area. I don’t think that means you can’t attend, but if you’re worried about it, just say you’re a Pasadena community member. The Pasadena community is very cosmopolitan. If you’ve ever shopped at a Trader Joe’s or watched the Rose Parade, both Pasadena institutions, you’re practically a townie.
What am I doing to cope with the pandemic? This:
Running: OUTSIDE
The weather in New York City has spiked to real spring temperatures (which, thankfully, can be considered appropriate for March), and yesterday I was able to go running outside for the first time in months.
It was really liberating. It’s harder to run inside, and there’s absolutely no circumstances under which I think anyone should ever be unmasked indoors, which is definitely something that interferes with running. Outdoors, on the other hand, if you can stay about 10-15 feet away from others? I think that it’s reasonable and viable to exercise without a mask under those circumstances. I tend to make a judgment call when I arrive at the park, based on how crowded the path is. Yesterday evening it was surprisingly empty despite the good weather, so I was able to make the most of it.
I’ve commented here before on how I think gyms that use masking, occupancy limits, and a 6-foot distancing rule can be safe, provided the overall prevalence of COVID-19 in the surrounding community is low. However, outside will always be safer under equivalent conditions, and I’m delighted to be able to return there for exercise even when it’s crowded and I have to mask up. It’s a chance to get some much-needed vitamin D, and not have to be stuck on a treadmill watching cable news.
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See you all next time.
Always,
JS