Injection-site reactions to booster doses of acellular pertussis vaccine: rate, severity, and anticipated impact.

BACKGROUND: Acellular pertussis (aP)-containing vaccines cause fewer adverse events than whole-cell versions for primary doses. Booster doses, however, may be followed by extensive injection-site reactions. This study compares the frequency, severity, and impact of local reactions among children receiving 5 consecutive doses of an aP combination vaccine (including inactivated polio virus, conjugated Haemophilus influenzae type b antigen, and diphtheria and tetanus toxoids) to children receiving a mixed series of whole-cell and aP combination vaccines. METHODS: Participants were parents or guardians of children 4 to 6 years old immunized at public health clinics across British Columbia, Canada. This included 398 children receiving the fifth consecutive dose of an aP combination vaccine and 402 receiving the fifth dose in a mixed series consisting of at least 1 prior dose of whole-cell pertussis combination vaccine with the remainder as aP combination vaccine. A cross-sectional telephone survey evaluated the extent of local reactions 48 to 96 hours after immunization by asking participants to compare the size of redness and swelling with familiar household items such as Oreo cookies or coins. Associated discomfort and impact on recreational activities, health care utilization, parental time off work, and attitudes toward immunization were also assessed. RESULTS: Children who received the fifth consecutive dose of an aP combination vaccine more often experienced redness (24%) or swelling (16%) the size of an Oreo cookie or larger (>or=46 mm) than children given a mixed series (10% and 9%, respectively) but less often experienced tenderness or limitation of movement at the injection site. Related health care utilization was low. There was no discernible effect on participation in recreational activities or parental attitudes toward vaccine; 90% would recommend the same vaccine to others with children of the same age. CONCLUSIONS: We conclude that injection-site reactions are more extensive after the fifth consecutive dose of an aP combination vaccine compared with the fifth dose in a mixed series of whole-cell and aP combination vaccines. These reactions are unlikely to affect parental acceptance of immunization recommendations or health care utilization.

Does antigen-specific cytokine response correlate with the experience of oculorespiratory syndrome after influenza vaccine?

During the 2000-2001 season in Canada, a newly identified oculorespiratory syndrome (ORS) was observed in patients after immunization with inactivated influenza vaccine. ORS was associated with a high proportion of microaggregates of unsplit virions in the implicated vaccine and had clinical features suggesting delayed-onset hypersensitivity. We explore the association between in vitro cytokine balance (type 1 vs. type 2) and clinical ORS after influenza vaccination. We report the balance of interferon (IFN)-gamma, interleukin (IL)-10, IL-5, and IL-13 expression by peripheral blood mononuclear cells (PBMC) among unvaccinated, vaccinated ORS-affected, and vaccinated ORS-unaffected persons after in vitro challenge with implicated and nonimplicated vaccines. Antigen-stimulated PBMC from vaccinated persons produced significantly more IFN-gamma than did those from unvaccinated persons. There was a statistically significant type 2 polarization among unvaccinated compared with vaccinated persons. Although vaccinated ORS-affected individuals had less of a type 1 basis than did vaccinated unaffected individuals, this difference was not statistically significant.

The changing age and seasonal profile of pertussis in Canada.

During the postvaccine era in Canada, most cases of pertussis have been reported in children <5 years of age, with the highest incidence, morbidity, and mortality in infants <1 year old. Population-based data, with very high laboratory confirmation rates and hospital separation and mortality statistics, chronicle the changing age and seasonal profile associated with pertussis over recent successive outbreaks in British Columbia, Canada. A large outbreak during 2000 highlights 2 important changes to the postvaccine profile. For the first time in Canada, the incidence of pertussis among preteens and teens surpassed that of all other age groups. At the same time, a decreasing incidence of pertussis among infants and preschool children highlights reduced susceptibility in the very young. Recent changes in the childhood immunization program (including introduction of an acellular pertussis vaccine), waning immunity, and changes in laboratory methods are considered in explaining these 2 simultaneous but divergent trends in the pertussis profile.

Skin testing to evaluate oculo-respiratory syndrome (ORS) associated with influenza vaccination during the 2000-2001 season.

A syndrome of red eyes and respiratory symptoms was noted following receipt of influenza vaccine in Canada during the 2000-2001 influenza season. We conducted intra-dermal skin testing to determine if oculo-respiratory syndrome (ORS) was related to failure of the splitting process during vaccine manufacturing, if it was associated with a particular viral strain and to identify individuals at risk for subsequent ORS reaction. Skin testing with minute quantities of vaccine antigen induced ORS symptoms at a higher rate amongst persons previously affected by this syndrome compared to previously unaffected persons. Skin test reaction size or quality could not identify persons at risk of ORS. Skin testing could not identify a specific strain or the stage in the manufacturing process during which the trigger may have been introduced.