Smartwatch data pre/post covid vaccination
This study was just published in an offshoot journal of one of the most prominent science journals, Nature. It is part of a prospective study that was done in the first half of 2021, and looked at a cohort of individuals who wore smartwatches before and after their second and third covid/Pfizer vaccinations. The methods are a bit odd - they blend the results of two different studies and are effectively studying a group of 116 individuals who had registered for both studies.
The authors omitted a few points from mention, which I would like to highlight.
1) In Figure 3, which shows average heart rate and “stress measure” according to reaction to vaccination (none/mild/severe), we see that individuals with severe reactions appear to have abnormal stress measures persisting out to two weeks - this includes a 1-2 day period of decreased stress measure at the 120-168 hours post-vaccination period - which appears to correspond to a period of decreased heart rate - as well as elevated stress measure up until the end of the observation period of 14 days. The elevated stress measure appears to correspond to several elevations in heart rate at the end of the observation period.
We can hypothesize that heart rate abnormalities in the “severe reaction” group may persist past 14 days.
2) In Table 1, “severe reaction” occurred in a reasonably large percentage of cases - 15% after second vaccination, 10% after third vaccination. The age of those who had severe reactions was younger, as measured by mean or median age.
3) In the Sup. Figure 5, severe reactions persisted out to the end of the observation period. As with (1), we hypothesize that severe symptoms persist beyond the 14-day observation period.
4) In Sup. Table 4, we see that severe reactions to the third vaccine appear to be most common in individuals who had a severe reaction to the second vaccine, with 4 out of 5 of those having a severe booster reaction being represented.
Given that this data was collected over one year ago, it is unfortunate that it is only available in peer-reviewed format now. Because of the odd methodology, there are many more opportunities for individuals to be lost to followup. There is no information given here as to clinical outcomes, i.e. whether any members of the cohorts were hospitalized.
Presumably these concerns were addressed in peer-review, considering that this is one of the world’s premier science journals.
Dear Jean Marc - Although just one anecdotal account, I would be happy to share my pre and post vax story with you.
I am late 40's, very fit, and an avid mountain biker. I wear an Apple watch while biking, which tracks distance, HR, etc. 1 week post-vax my heart rate was a full 20 bpm above my averages for the same rides. I had been experiencing shortness of breath and a feeling like I was "out of air", but would not have given it too much thought without the smart watch data. I showed it to a cardiologist who is a client of mine, and he just about hit the floor. He also said they had been fielding a large number of calls/complaints with similar issues from athletic patients. No surprise, but people who track their performance are more sensitive to deviations form the norm.
I had to take 2+ months off of intense exercise. My family doc refused to answer any questions intelligently once I told her that I felt the issue had to be related to the mRNA shot.
It is very unfortunate that these matters are not taking a more prominent position in the discussion around teh continued "jabbing" of healthy people.
P.S. On Covid - I had it in the late spring of 2020. Felt like a mild cold that lasted 3 days. Nothing to be concerned with for me...