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Reflections on a third reported allergic reaction to the Pfizer vaccine, perhaps the first in the U.S.
A thread
(1/ https://www.nytimes.com/2020/12/16/health/covid-pfizer-vaccine-allergic-reaction.html
A thread
(1/ https://www.nytimes.com/2020/12/16/health/covid-pfizer-vaccine-allergic-reaction.html
We know relatively little about these cases and there is a lot of speculation. Each new case will continue to get more and more attention and likely confirm priors for many - e.g. vaccines unsafe - even as the incident rate falls due to the denominator growing every day
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(2/
So, what do we know? (1) patients with a history of vaccine allergy were excluded from the Pfizer trials; (2) 44,000 such participants were monitored for safety in the trials; (3) the rate of allergic reactions was zero-point-six-three PERCENT (N=137) in those vaccinated
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(3/
compared to zero-point-five-one percent (N=111) in the placebo group. So, not huge numbers.
But this is a very different vaccine technology. Most vaccines grow the bug various ways and then kill or weaken it to create the immune stimulus needed
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But this is a very different vaccine technology. Most vaccines grow the bug various ways and then kill or weaken it to create the immune stimulus needed
(4/
Here we are injecting mRNA encoded in liposomes, an approach that we have not used in routine immunization campaigns before. I think we would do well to acknowledge that fact. We just don't have a lot of experience with this technology.
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(5/
Now, it's most likely that real world use will mirror the Phase 3 trial experience. But sometimes toxicities develop that weren't seen in the trials. That's why FDA, aware of the UK cases, has required Pfizer to conduct very close surveillance of allergic reactions
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(6/
What does this mean for patients? The FDA and CDC have clearly said that patients allergic to foods, medicines, or other triggers need not avoid this vaccine - that the main concerns are in those who have potentially had reactions to a specific vaccine component
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(7/
The two UK patients both had allergic conditions that required epinephrine autoinjectors, and they both received epinephrine after the vaccine and have apparently done well. Not sure yet about this Alaska patient.
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(8/
Keep in mind that allergic reactions to vaccines tend to happen quickly and are generally manageable. For those who have concerns, ask your allergist and consider receiving the vaccine in a setting where anaphylaxis can be treated; our offices handle this every day.
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(9/
I for one think the risks of COVID far exceed the risks of this vaccine, especially when administered in an appropriate setting. I got an email today that my hospital got their first shipment and I'm already signed up. I can't wait to get my dose and will post when I do!
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