Death and serious illness following influenza vaccination: a multidisciplinary investigation.
OBJECTIVE
To evaluate a possible association between influenza vaccination and four deaths and four serious illnesses among 114 recent influenza vaccinees in a long-term care facility (LTCF) and two deaths from a nearby physician's office. All had received vaccine from the same lot (Lot A).


METHODS
Field investigation including (1) a retrospective cohort study among LTCF residents who received Lot A or other influenza vaccine, (2) review of medical records of cases of death or serious illness, (3) active surveillance of deaths among 1500 community based Lot A vaccinees and (4) laboratory testing of vaccine from available Lot A vials.


RESULTS
Medical record reviews showed no common clinical syndrome or cause of death. Laboratory testing of Lot A samples revealed no evidence of tampering and no differences compared to an unrelated lot. The risk of death or hospitalization was not significantly different between persons who received Lot A versus a comparison lot, Lot B (incidence rate ratio (IRR) = 0.9, 95%CI = 0.3-3.3).


CONCLUSIONS
There was no clinical or biological evidence pointing to inherent vaccine safety issues, nor was there a detectable increased risk of death or hospitalization among persons vaccinated with Lot A. Lot specific clustering of adverse events (AEs) may reflect medical events causally unrelated to vaccination. Rapid investigations of potential AEs are important to ensure vaccine safety and to maintain public and healthcare provider confidence in vaccines.
National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Immunization Safety Office (ISO), Division of Healthcare Quality Promotion, Atlanta, GA 30333, USA. bwf8@cdc.gov
Alison
A
Rue-Cover
John
J
Iskander
Shauna
S
Lyn
Dale R
DR
Burwen
Paul
P
Gargiullo
Sean
S
Shadomy
Joel
J
Blostein
Carolyn B
CB
Bridges
Penina
P
Haber
R Duane
RD
Satzger
Robert
R
Ball
Jane F
JF
Seward
D016907:Adverse Drug Reaction Reporting Systems; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006760:Hospitalization; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D008134:Long-Term Care; D008297:Male; D012189:Retrospective Studies; D012306:Risk; D014611:Vaccination / Q000009:adverse effects* / Q000401:mortality*
D007252:Influenza Vaccines