Background mortality rates crucial to interpreting post-vaccination deaths

The background mortality rates or the rates of death irrespective of cause are key to accurately reporting post-immunization deaths, according to a recent study published in the American Journal of Preventive Medicine.

Researchers with the U.S. Centers for Disease Control and Prevention used the Vaccine Safety Datalink, a comprehensive medical database, and found that the VSD mortality rate after immunization is lower than the general U.S. population mortality rate. The study also determined that the top four causes of death were the same in the VSD and the more generalized National Center for Health Statistics system.

Public concern about deaths and other adverse events after immunization can lead to a disruption in immunization programs and result in an increase in vaccine-preventable disease.

"Determining the baseline mortality rate in a vaccinated population is necessary to be able to identify any unusual increases in deaths following vaccine administration," Natalie McCarthy, the lead investigator of the study, said.

The findings of the study could be used in communications to the public about vaccine safety risks to allay concerns.

"Although there is currently no evidence to support a causal relationship between vaccinations and death, this study provides background mortality rates following vaccination to be used as a baseline when examining the safety profiles of new vaccines and during mass immunization campaigns," McCarthy said.