Safety profile of smallpox vaccine: insights from the laboratory worker smallpox vaccination program.
BACKGROUND
The frequency of mild-to-moderate adverse events following smallpox vaccination was not well documented or reported during the pre-eradication era. This report describes the frequency of such symptoms among 936 adult smallpox vaccinees with and without a history of prior smallpox vaccination.


METHODS
Diary cards were distributed to 1006 laboratory workers and members of the Centers for Disease Control and Prevention (CDC) smallpox response team who received smallpox vaccination under an investigational new drug protocol during 2001-2002. Vaccinees were requested to complete the diary card daily and return it to the CDC 28 days after vaccination. The proportion of vaccinees reporting symptoms was determined and compared among subgroups.


RESULTS
Ninety-three percent of the diary cards were returned. The most common symptom reported was "itching at vaccination site." Primary vaccines reported statistically higher proportions of the following 11 symptoms: joint pain (25% vs. 11%; P=.0011), muscle pain (46% vs. 19%; P<.0001), fatigue (43% vs. 29%; P=.0161), swelling at vaccination site (58% vs. 33%; P<.0001), itching on the body (31% vs. 17%; P=.0048), abdominal pain (11% vs. 2%; P=.0012), swollen or tender lymph nodes (71% vs. 33%; P<.0001), pain at injection site (48% vs. 30%; P=.0018), headache (40% vs. 25%; P=.0088), backache (17% vs. 7%; P=.0090), and fever (temperature, >or=100 degrees F [37.7 degrees C]; 20% vs. 9%; P=.0047).


CONCLUSIONS
This analysis suggests that previously unvaccinated persons aged <30 years experienced more symptoms than did previously vaccinated persons. The findings of increased proportions with joint pain, abdominal pain, backache, and difficulty breathing were unexpected. As with recently described cardiac adverse events, these symptoms are suggestive of systemic involvement and warrant further study.
Baggs
James
J
Centers for Disease Control and Prevention, National Immunization Program, Epidemiology and Surveillance Division, Immunization Safety Branch, 1600 Clifton Rd., Mailstop E61, Atlanta, GA 30333, USA. jbaggs@cdc.gov
Chen
Robert T
RT
Damon
Inger K
IK
Rotz
Lisa
L
Allen
Christopher
C
Fullerton
Kathleen E
KE
Casey
Christine
C
Nordenberg
Dale
D
Mootrey
Gina
G
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D012307:Risk Factors; D012900:Smallpox Vaccine / Q000009:adverse effects*
D012900:Smallpox Vaccine