Severe or life-threatening VAEs are more likely to be reported voluntarily and may also be more likely to be investigated.Ĭlustering of adverse events or disease can serve as an indicator of a potential association between an adverse event and vaccine administration. Trends in reports of vaccine-associated events (VAE) may be related to the immunogenicity of the vaccine, improper administration of a vaccine, a veterinarian's or owner's perception of an association between the event and vaccination, and/or the inclination of the veterinarian or owner to initiate a report. This type of surveillance provides case (numerator) information only, and it is often characterized by underreporting and variability in report quality. Traditional post-marketing surveillance of veterinary vaccines relies on veterinarians or owners to voluntarily report suspected reactions to manufacturers or to the US Department of Agriculture (USDA), the federal regulatory agency for animal vaccines.
