I recently popped down to the US from British Columbia for a family visit, with much of the time spent searching for a PCR test that would be resulted within 72 hours (which no one would guarantee), currently required of all Canadians returning home. Ultimately, I had three negative results in hand as well as proof of vaccination and an extensive quarantine plan ready for the border agent, who really only wanted to know the exact volume of my hard cider stash.
But since I had to visit several drug stores to get tested, I took advantage of the opportunity to get my flu vaccine. Despite minimal arm discomfort, I was up all night with neck and shoulder pain. The following morning, I did routine yearly lab testing for a Longitudinal Study on Aging. To my great surprise, the results returning days later showed a 100-fold increase in my (normally almost unmeasurable) hsCRP levels. This prompted some quick research.
Indeed, I learned, influenza vaccines can be associated with transient increases in acute phase reactants (such as CRP), albeit typically in the 1.5 x normal range. I had also received my Moderna booster exactly 2 weeks prior.
Looking for any evidence of COVID vaccination as a possible confounder, I discovered an
