Had 4th vaccination, 2nd booster, 10 days ago. The first 2 vaccinations were Pfizer, only the 2nd one gave me issues as I made the mistake of mowing lawns and doing garden maintenance in the afternoon, so for the 3rd and 4th shots I made sure to do nothing for 24hrs. The boosters have each been Moderna. Last week Mrs prozac complained of a sore arm in the vicinity for a few days. No issues on my part.