<span class="word">Multiple <span class="word"><span class="changedDisabled">Increasing <span class="word"><span class="changedDisabled">Vaccine <span class="word"><span class="changedDisabled">Adverse <span class="word"><span class="changedDisabled">Events <span class="word"><span class="changedDisabled">Safety <span class="word"><span class="changedDisabled">Signals <span class="word">for <span class="word"><span class="changedDisabled">Older <span class="word"><span class="changedDisabled">Adults

Immune responses naturally decline with age in the elderly; this process is named immunosenescence. The risks for adverse events (AEs) can increase, decrease, or be uncorrelated with increasing age. Safety signals associated with vaccines can be detected within the Vaccine Adverse Event Reporting System (VAERS). Herein, VAERS was retrospectively examined for safety signals associated with the elderly. In general, common AEs include normal immune responses and also injection site-related AEs. For multiple COVID-19 vaccines, breakthrough infections and COVID-19-related AEs had unexpectedly high normalized frequencies. The normalized frequency for AE death was elevated for multiple vaccines, including COVID-19 vaccines; the associated risk appears to be additive for coadministered combinations of the COVID-19 Janssen vaccine with either the COVID-19 Pfizer-BioNTech BNT162b2 or the COVID-19 Moderna mRNA-1273 vaccine. Multiple manufacturing lots for the COVID-19 Janssen, COVID-19 Pfizer-BioNTech BNT162b2, and Moderna mRNA-1273 vaccines have high AE death normalized frequencies. These observations, combined with rapid AE death onset following vaccination, likely point to possible manufacturing contamination of specific manufacturing lots; endotoxins are a possible causative constituent. The sensitivity to these causative constituent(s) increases with age in the elderly.