Safety assessment of recalled Haemophilus influenzae type b (Hib) conjugate vaccines--United States, 2007-2008.
OBJECTIVE
On 13 December 2007, Merck & Co., Inc. voluntarily recalled 1.2 million doses of Haemophilus influenzae type b (Hib) vaccines that had been distributed since April 2007 for concerns regarding potential Bacillus cereus contamination. Enhanced postrecall surveillance was conducted to detect vaccine-associated B. cereus infections.


METHODS
We reviewed reports involving recalled Hib vaccines received by the Vaccine Adverse Event Reporting System (VAERS) during 1 April 2007-29 February 2008. For each reported death, autopsy review sought evidence of B. cereus infections. For each specified outcome, the proportional reporting ratios (PRRs) were calculated to compare the recalled Hib vaccines with the manufacturer's nonrecalled Hib vaccines in the VAERS databases. On 20 December 2007, we used the Epidemic Information Exchange (Epi-X) to solicit nongastrointestinal vaccine-associated B. cereus infections, and requested B. cereus isolates for genotyping to compare with the manufacturing facility isolate.


RESULTS
VAERS received 75 reports involving recalled Hib vaccines; none described a confirmed B. cereus infection. Comparative analyses did not reveal disproportionate reporting of specified outcomes for recalled Hib vaccines. The Epi-X posting triggered one report of vaccine-associated B. cereus bacteremia from a child who received a nonrecalled Hib vaccine manufactured by Merck; the genotypes of isolates from the patient and the manufacturing facility differed.


CONCLUSIONS
No evidence of vaccine-associated B. cereus infection had been found in recipients of recalled Hib vaccines. Conducting laboratory surveillance through Epi-X was feasible and may enhance public health response capacities for future vaccine safety emergencies.
Huang
Wan-Ting
WT
Epidemic Intelligence Service, Career Development Division, Office of the Workforce and Career Development, Centers for Disease Control and Prevention (CDC), Atlanta, GA 30333, USA.
Chang
Soju
S
Miller
Elaine R
ER
Woo
Emily Jane
EJ
Hoffmaster
Alex R
AR
Gee
Jay E
JE
Clark
Thomas A
TA
Iskander
John K
JK
Ball
Robert
R
Broder
Karen R
KR
D016907:Adverse Drug Reaction Reporting Systems / Q000706:statistics & numerical data*; D016863:Bacillaceae Infections / Q000209:etiology*; D001409:Bacillus cereus / Q000302:isolation & purification*; D002675:Child, Preschool; D004340:Drug Contamination; D056736:Drug Recalls / Q000706:statistics & numerical data; D005260:Female; D005838:Genotype; D018073:Haemophilus Vaccines / Q000009:adverse effects* / Q000592:standards; D019741:Haemophilus influenzae type b / Q000276:immunology; D006801:Humans; D007223:Infant; D008297:Male; D014481:United States; D018074:Vaccines, Conjugate / Q000009:adverse effects / Q000592:standards
D018073:Haemophilus Vaccines; D018074:Vaccines, Conjugate