By Louise Gagnon
TORONTO, CANADA -- May 7, 2007 -- Health-care workers who are in contact with children should be counselled about the potential adverse effects of being vaccinated for pertussis, according to an investigator who presented a study here at the annual meeting of the Pediatric Academic Societies (PAS).
Adults can transmit pertussis to children, and for that reason, the U.S. Advisory Committee on Immunization Practices (ACIP) in 2006 recommended that all healthcare workers should receive a single dose of the Tdap (tetanus, diptheria, and acellular pertussis) vaccine, said Thomas J. Sandora, MD, MPH,, an infectious disease specialist in the division of infectious diseases at Children's Hospital Boston and instructor, department of paediatrics, Harvard Medical School, Boston, Massachusetts, United States.
According to Dr. Sandora, even adults who were vaccinated against pertussis as children, would have lost some immunity to pertussis by the time they reach adulthood because immunity wanes over time.
"Children can be re-exposed to pertussis from adults because the immunity of adults has waned," he said in his poster session on May 6th. "Healthcare workers in particular are at high risk for transmitting pertussis to patients. It's particularly important that they get the vaccine if the healthcare workers are in contact with high-risk kids."
Available since 2006 in the U.S., the vaccine is a tetanus diptheria booster, which has the addition of acellular pertussis, he explained. While the standard recommendation for adolescents and adults is to receive the vaccine 5 to 10 years after the last tetanus booster, he noted, the recommendation for healthcare workers is an interval of as short as two years.
In their study, Dr. Sandora and colleagues contacted 207 healthcare workers at Children's Hospital Boston two weeks after vaccination and questioned about adverse events they experienced after receiving the vaccine.
Common adverse events reported were pain at the injection site (77%), swelling at the injection site (11%), and redness at the injection site (7%). They also reported systemic adverse events such as headache (9%), fatigue (14%), and fever (4%).
The median duration of symptoms was three days for local side effects and two days for systemic side effects.
Investigators found a shorter interval was significantly associated with pain at the injection site (P =.03), but the interval did not play a role in the development of other symptoms. "It's less likely you would have pain [at the injection site] if it has been more than 10 years since your last tetanus booster," said Dr. Sandora.
Healthcare workers aged under 30 years were more likely to experience headache (RR 3.2) and fatigue (RR 3.1) than those over 30.
A total of 0.5% of respondents said the side effects interfered with work activities, and 6% said the side effects interfered with non-work related activities such as exercising or driving.
"This will assist with counselling," said Dr. Sandora. "When people get their vaccine, we can tell them what local and systemic side effects they can expect."
The study was independently conducted.
[Presentation title: Adverse Events After Tdap Vaccine in Healthcare Workers. Abstract 6293.12]
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