3 tables omitted
During January 24–April 18, 2003, smallpox vaccine was administered
to 33,444 civilian health-care and public health workers in 54 jurisdictions
to prepare the United States for a possible terrorist attack using smallpox
virus. This report updates information on vaccine-associated adverse events
among civilians vaccinated since the beginning of the program and among contacts
of vaccinees, received by CDC from the Vaccine Adverse Event Reporting System
(VAERS) as of April 18.
In this vaccination program, CDC, the Food and Drug Administration,
and state health departments are conducting surveillance for vaccine-associated
adverse events among civilian vaccinees.1 As part of the vaccination
program, civilian vaccinees receive routine follow-up, and reported adverse
events after vaccination receive follow-up as needed. The U.S. Department
of Defense is conducting surveillance for vaccine-associated adverse events
among military vaccinees and providing follow-up care to those persons with
reported adverse events.
Adverse events that have been associated with smallpox vaccination are
classified on the basis of evidence supporting the reported diagnoses. Cases
verified by virologic testing are classified as confirmed. Cases are classified
as probable if possible alternative etiologies are investigated and excluded
and supportive information for the diagnosis is found. Cases are classified
as suspected if they have clinical features compatible with the diagnosis,
but either further investigation is required or investigation of the case
did not provide supporting evidence for the diagnosis. All reports of events
that follow vaccination are accepted (i.e., events associated temporally);
however, reported adverse events are not necessarily associated causally with
vaccination, and some or all of these events might be coincidental.
As of April 18, a total of 10 cases of myopericarditis have been reported;
one new report was received during April 14-18. During the same period, one
new case of acute myocardial infarction (MI) was reported. Five cases of acute
MI were previously reported.1,2
Case 1. A woman aged 56 years with no history
of heart disease was revaccinated on April 1. Approximately 1 week later,
she had palpitations and was noted to have premature ventricular contractions
on cardiac monitor. She did not report chest pain. On April 15, cardiac consultation
indicated an effusion on her echocardiogram and mitral regurgitation. A working
diagnosis of myocarditis/pericarditis was made. The patient was treated with
nonsteroidal anti-inflammatory drugs and investigation continues.
Case 2. A man aged 49 years with no personal
or family history of coronary artery disease was revaccinated on March 12.
On the evening of April 7, he had an episode of chest pain that he attributed
to indigestion. On April 8, while driving, he experienced increasingly severe
chest pain, dyspnea, and diaphoresis. In the emergency department, an electrocardiogram
showed nonspecific ST- and T-wave abnormalities and poor R-wave progression,
all consistent with an anterior MI. Total creatine kinase and troponin-I assays
were substantially elevated. Cardiac catheterization indicated an anterior
MI caused by complete occlusion of the left anterior descending artery. Successful
percutaneous transcoronary angioplasty and stent placement were performed,
and the patient managed with aspirin, heparin, and intravenous beta-blockers.
He is recovering at home.
During April 14-18, one new case of generalized vaccinia and two cases
of inadvertent inoculation (nonocular) were reported. During the vaccination
program, no cases of eczema vaccinatum, erythema multiforme major, fetal vaccinia,
postvaccinial encephalitis or encephalomyelitis, progressive vaccinia, or
pyogenic infection of the vaccination site have been reported.
During April 14-18, in addition to the MI, nine other serious adverse
events were reported, including one case of atypical chest pain and one case
of anoxic encephalopathy. Also during this period, 42 other nonserious events
were reported. Among the 369 vaccinees with reported other nonserious adverse
events during January 24–April 18, the most common signs and symptoms
were fever (n = 78), rash (n = 69), headache (n = 56), and pain (n = 56).
All of these commonly reported events are consistent with mild expected reactions
following receipt of smallpox vaccine. Some vaccinees reported multiple signs
During the current reporting period, information was received about
one inadvertent contamination of a vaccine vial when a vaccinator was observed
placing a needle from a vaccinee back into the vial, then removing the needle
from the vial and discarding it. The vial was then used to vaccinate additional
persons, but new needles were used. The initial vaccinee was tested for hepatitis
B virus, hepatitis C virus, and human immunodeficiency virus; all tests were
negative. Investigation is ongoing for evidence of any complications from
During this reporting period, no vaccinia immune globulin was released
for civilian vaccinees. No cases of vaccine transmission from civilian vaccinees
to their contacts have been reported during the vaccination program. A total
of 14 cases of transmission from military personnel to civilian contacts have
been reported. Surveillance for adverse events during the civilian and military
smallpox vaccination programs is ongoing; regular surveillance reports will
be published in MMWR.
Smallpox vaccine adverse events coordinators; National Immunization
This report highlights the need to ensure proper infection-control procedures
to avoid contamination of multidose vials. A recent supplement to the Advisory
Committee on Immunization Practices (ACIP) recommendations for using smallpox
vaccine states that the needle should not be reinserted into the vaccine vial.3 CDC's Smallpox Fact Sheet (http://www.bt.cdc.gov/agent/smallpox/vaccination/vaccination-method.asp) states that the same needle should never be dipped into the vaccine
vial more than once to avoid contamination of the vaccine vial.4 Immediately
after use, each presterilized needle should be disposed of in a biohazard
waste container for sharp objects. Potentially contaminated vials should be
discarded. Vaccinees who receive potentially contaminated vaccine should be
offered follow-up testing for infectious diseases of concern, if possible,
based on knowledge of test results from the initial vaccinee. Incidents of
potentially inappropriate administration of smallpox vaccine should be reported
to VAERS at http://www.vaers.org.
This report includes cases reported as of April 18 that are either under
investigation or have a reported final diagnosis. Because of ongoing discussions
of final case definitions, numbers and classifications of adverse events might
change and will be updated regularly in MMWR.
References: 4 available
Update: Adverse Events Following Civilian Smallpox Vaccination—United States, 2003. JAMA. 2003;289(18):2351-2355. doi:10.1001/jama.289.18.2351