Pain Adverse Events, Bell’s Palsy, and Guillain-Barré Syndrome Following Vaccination

Objective: Some individuals (vaccinees) experience pain related adverse events following vaccinations. The majority of these pain related vaccination reactogenicity adverse events resolve within days. Rare adverse events like Bell’s palsy and Guillain-Barré syndrome (GBS) have been associated with some vaccines. Herein, multiple working hypotheses are examined in the context of available characteristics of vaccinees and onset of these pain related adverse events post vaccination. Methods: The Vaccine Adverse Event Reporting System database was data mined for pain associated vaccine adverse events data by vaccine, age, gender, dose, and onset post vaccination. Results for vaccines with the highest number of pain related adverse events were compared. Results: For the pain related adverse events examined, the highest number of adverse events are reported within 1 day, roughly half this number the second day, and roughly a quarter this number by the third day. The day of onset for these pain related adverse events approximates a power of two decay pattern for the first three days. This same pattern is observed for all of the vaccines with the highest number of pain related adverse events. The consistency of these day of onset frequency patterns of examined adverse events following vaccinations for multiple unrelated vaccines enables the exclusion of specific vaccine components and excipients as specifically causative entities. Conclusion: The observed onset occurrences of examined pain associated adverse events are consistent with likely etiology relationship with innate immune responses to vaccinations for multiple vaccines including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) coronavirus disease 2019, influenza, and additional vaccines. Innate immune responses may be contributing to the initial etiology of Bell’s palsy and GBS post SARS-CoV-2 mRNA and adenoviral vaccinations.