Thread by @DrAkilahJ

So much talk this morning about the headlines re:  #Pfizervaccine and #allergicreaction. Let’s not add to the fire. #MedTwitter #AllergyTwitter
#Allergists are losing it... myself included... a long thread... 1/

https://twitter.com/wsj/status/1336660652358856704

First, the reports do not give us any details about the reactions.  In allergy practice of the most important things is the history. What were the symptoms, what was the timing, what is the patient’s previous history? Without this, we shouldn’t jump to conclusions. 2/

Second, in the Phase 3 data released by Pfizer there was a report of a “slight imbalance” in potential allergic reactions in the vaccine group when compared to the placebo group at a rate of 0.63% compared to 0.51%… that is VERY VERY SMALL. 3/

None of these were reported as anaphylaxis (severe allergic reaction), or anaphylactoid (mimicking anaphylaxis but different mechanism) in any study participants. 4/

Third, we should always be cautious, especially with new vaccines and drugs, but this seems like a completely knee jerk reaction, based on 2 events out of THOUSANDS. The risk of anaphylaxis after vaccination is VERY RARE.. about 1 in a million in general. 5/

Despite this UK says “any person with a history of a significant allergic reaction to a vaccine, medicine or food(such as previous history of anaphylactoid reaction or those who have been advised to carry an adrenaline autoinjector)shouldn’t receive the Pfizer/BioNtech vaccine”6/

I DO NOT GET IT. 
 
Fourth, In practice, we try to identify the component of the vaccine that is the culprit allergen. More often than not the culprit is an additive or residual vaccine component rather than the actual part of the vaccine that’s doing the work… 7/

Also, in practice, we consider the risk of reaction vs the risk of disease, and usually the risk of disease is higher so we still vaccinate, although we may split doses, dose under close observation, etc. Generally, THERE ARE FEW ABSOLUTE CONTRAINDICATIONS TO VACCINATION 8/

Fifth, all allergies are not the same… and anaphylactoid is completely different.  What does a medication or food allergy have to do with allergy to a vaccine? ABSOLUTELY NOTHING. 9/

If you’ve had an allergic reaction to one vaccine, will you have a reaction to another? DEPENDS ON WHAT VACCINE COMPONENT YOU’RE REACTING TO.  If you’ve reacted to a vaccine in the past, should you avoid all vaccines in the future? NO, YOU SHOULD STILL BE VACCINATED. 10/

If you carry an EpiPen for allergies, should you avoid getting a vaccine? YOU SHOULD PROBABLY STILL GET A VACCINE. Just because you have an allergy to something, does not mean you’re allergic to everything. 11/

For example, I’m allergic to some foods, but I am not allergic to ALL foods.  It would not make sense for me to avoid foods I am not allergic to simply because I am allergic to some foods. GET IT? 12/

So, these headlines and knee jerk reactions are super frustrating. Rather than flashy headlines, and making huge policy decisions based on incomplete information, perhaps we should wait for more information, and use that information to come up with a plan based in SCIENCE, 13/

so that we do not add to vaccine fears and all of the misinformation surrounding #Covid_19 COVID-19. I hope the @FDA addresses this during tomorrow’s public meeting, and I hope that whatever they decide is based on good SCIENCE and nothing else.  Rant over. 14/