Vaccine Update (FWIW):
Yesterday around 7:00pm I started to feel a little nauseous but am not sure if it was the leftover chili I had for dinner, my mind playing tricks, or the vaccine. The nausea persisted most of the night and I dozed a bit until my wife got home around 1:00am. We chatted for a bit but right at 2:00am I was hit pretty abruptly with large muscle aches in the lower back, legs, and shoulders. It felt like an illness but without the other stuff (cough, stuffy nose, fever). I took some Tylenol and dozed on the couch until 5:30am and then went back to bed and slept pretty well for an hour or so.
It's now 7:20am and the nausea is still there a bit but muscles aren't sore now (other than the jet lagged feeling of poor sleep on the couch). The injection site is not sore at all. I'm curious to see how I feel the rest of the day. If I received the vaccine, this is would be one of the more intense reactions I've had to vaccines as I usually tolerate them well.
I have huge respect for you and all the trial participants who have volunteered for vaccine trials. Without you there would be no vaccine so thank you and I hope you feel better soon.
Your experience mirrors others I know who have been involved in a ChAdOx1 nCov-19 trial. There is no way of knowing which arm you are in but if you are in a study with saline placebo, it's likely you were in the experimental arm. Anecdotally, moderate reactions do seem to be a feature of the ChAdOx1 nCov-19 vaccine thought to be due to how immunogenic the spike protein is. I believe the mRNA platforms also had this effect but exogenous RNA is also a potent inflammatory stimulus in itself. Interestingly, adverse effects seem to be fewer in older people which makes sense as they are likely to have a less "brisk" immune response (but I won't ask you to reveal your age!)