An article published today on Reuters and elsewhere reads, "Israeli survey finds 3rd Pfizer vaccine dose has similar side effects to 2nd." Buried within this article is the following:
About 0.4% said they suffered from difficulty breathing, and 1% said they sought medical treatment due to one or more side effect.
This seemed quite bad to me and like a worrisome result. I sought information on how many sought medical treatment after the second shot. I could not find this information, but I did find:
only 51 of some 650,000 people to have received the Pfizer shot sought medical attention for symptoms suffered
from a December 2020 article on Israeli vaccination. Comparing the 1% to 51/650000 = 0.008% I found that the current frequency of side effects requiring medical attention was 128x the level found after dose 1. This seemed like a bad sign.
I then sought out more information about side effects post dose 2 in Israel, which I did not find. But instead I looked at the CDC's Advisory Committee on Immunization Practices’ Interim Recommendation for Moderna, and found the following:
The frequency of serious adverse events** observed was low in both the vaccine (1.0%) and placebo (1.0%) recipients
** Serious adverse events are defined as any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, or results in persistent disability/incapacity.
I can't believe that this was 1%! That seems surprisingly high (for either group). I expect the outside-of-trial data has not been nearly that magnitude.
This 1% matches the current Israeli data, and with a more restrictive definition, so the Israeli data no longer seems particularly worrisome in comparison, though I may dig in to this further. In general, I feel somewhat confused by the situation.
With such highly subjective soft outcomes a lot depends on the way the question is phrased and interpreted (if self-reporting). Thus comparing different populations and studies is almost impossible without really carefully digging into the original publications and even then it is fraught with problems.
If I have a rash post-vaccine and I go to see my GP or pharamcist, am I seeking medical help and is this worrisome? If I get up and later realize that I need to lie down or else I will faint (vasovagal syncope, around one in ten people have some form of need... (read more)