Reduced-antigen, combined diphtheria, tetanus, and acellular pertussis vaccine, adsorbed (boostrix(®)): a guide to its use as a single-dose booster immunization against pertussis.

Reduced-antigen, combined diphtheria, tetanus, and three-component acellular pertussis vaccine (Tdap; Boostrix(®)) is indicated for booster vaccination against diphtheria, tetanus, and pertussis. In clinical trials, a single booster dose of Tdap induced high seroprotective levels of antibodies to its three component acellular pertussis antigens in virtually all children and adolescents, and in a high proportion of adults and elderly individuals, at ≈1 month post-vaccination, irrespective of their vaccination history. Seropositivity rates for antibodies against pertussis toxin had begun to decline by 5 years after a booster dose of Tdap in adolescents/adults, with a subsequent booster dose 10 years later generally as immunogenic and as well tolerated as the initial booster. Tdap was safe and well tolerated in all age groups.

Combined vaccines - case study.

Application of the principles outlined in the WHO Guideline on Stability Evaluation of Vaccines is complicated by the nature of combination vaccines. Differences in degradation rates among the immunogens impose the restriction that shelf life is based on the most labile component. There is also a testing challenge with numerous components held at different stages of production.

Safety and immunogenicity of a pentavalent vaccine compared with separate administration of licensed equivalent vaccines in US infants and toddlers and persistence of antibodies before a preschool booster dose: a randomized, clinical trial.

OBJECTIVE: Our goal was to compare the safety and immunogenicity of a combination vaccine (DTaP(5)-IPV-Hib; Pentacel) with that of its separately administered, US-licensed equivalent vaccines (diphtheria, tetanus, 5-component acellular pertussis vaccine [DTaP(5); Daptacel], inactivated poliovirus vaccine [IPV; IPOL], and Haemophilus influenzae type b [Hib] vaccine [ActHIB]), when administered to infants and toddlers concomitantly with other routinely recommended vaccines and to assess antibody persistence from the fourth dose in toddlers to the fifth (preschool) DTaP(5) dose. SUBJECTS AND METHODS: In this randomized, multicenter study, 1939 healthy infants were immunized at 2, 4, and 6 months of age with 1 of 3 lots of DTaP(5) coadministered with IPV and Hib vaccines or 1 lot of DTaP(5)-IPV-Hib combination vaccine. Subsequently, 849 of these study participants were given a fourth dose of DTaP(5) and Hib vaccines or a fourth dose of DTaP(5)-IPV-Hib at 1 to 16 months of age. Safety was monitored throughout the study, and blood specimens were obtained to assess antibody responses. RESULTS: DTaP(5)-IPV-Hib elicited similar or fewer solicited injection-site and systemic reactions as compared with the separate administration of US-licensed DTaP(5), IPV, and Hib vaccines. Seroresponse and seroprotection rates elicited by DTaP(5)-IPV-Hib were noninferior to US-licensed equivalent vaccines after the infant series and after the fourth dose. Children immunized with DTaP(5)-IPV-Hib had higher antibody geometric mean concentrations to pertussis toxoid and filamentous hemagglutinin; children immunized with the separate vaccines had higher responses to pertactin. Hib antibody responses to Hib polysaccharide were nearly identical in the DTaP(5)-IPV-Hib and separate-vaccine groups. Persistence of antibodies to the fifth (preschool) dose was also similar between groups. CONCLUSIONS: DTaP(5)-IPV-Hib combination vaccine was shown to be immunogenic and well tolerated. No clinically important differences in the safety or immunologic profiles were noted for DTaP(5)-IPV-Hib versus the separately administered, US-licensed equivalent vaccines. DTaP(5)-IPV-Hib is a suitable replacement for separately administered DTaP, IPV, and Hib vaccines.

A kinetic study of histopathological changes in the subcutis of cats injected with non-adjuvanted and adjuvanted multi-component vaccines.

The aim of this study was to investigate the subcutaneous tissue response to administration of a single dose of multi-component vaccine in the cat. Three groups of 15 cats were injected with one of three vaccine products with saline as a negative control. Cats in group A received non-adjuvanted vaccine; cats in group B received vaccine with a lipid-based adjuvant; whilst those in group C were vaccinated with a product adjuvanted with an alum-Quil A mixture. The vaccine and saline injection sites were sampled on days 7, 21 and 62 post-vaccination. Biopsies of these vaccine sites were examined qualitatively and scored semi-quantitatively for a series of parameters related to aspects of the inflammatory and tissue repair responses. These data were analysed statistically, including by principal component analysis. At all three time points of the experiment, there was significantly less inflammation associated with administration of non-adjuvanted vaccine (p=0.000). Although there was evidence of tissue repair by day 62 in all groups, those cats receiving adjuvanted vaccines had evidence of residual adjuvant material accumulated within macrophages at this late time point. The severity of tissue reactions may vary significantly in response to vaccines which include adjuvants or are non-adjuvanted.

MMR vaccination, measles epidemiology and sero-surveillance in the Republic of Ireland.

OBJECTIVE: Following the introduction of a national measles and subsequent MMR vaccination programme, to determine the susceptibility of 3-14-year-old children to measles, mumps and rubella and to relate the results to the epidemiology of measles and the need for vaccination policy changes. DESIGN: Cross-sectional sero-survey and trends in measles notifications and mortality. SETTING: Paediatric hospital outpatient departments in Dublin. SUBJECTS: Sera were collected from 837 children attending the clinics in 1991 and 1992. RESULTS: The prevalence of antibodies in children aged 3-6, 7-10 and 11-14 years was 84, 83 and 95% for measles; 48, 60 and 65% for mumps; and 78, 63 and 74% for rubella, respectively. The prevalence of mumps antibodies may be underestimated. Ninety-six per cent of girls aged 13-14 years had rubella antibodies. A widespread outbreak of measles occurred in 1993. Over recent years, an increasing proportion of measles notifications were in older children. CONCLUSION: Given sub-optimal uptake of MMR vaccine, outbreaks of infection in pre- and primary school children are inevitable. In such circumstances, a 2-shot MMR vaccine programme with high uptake is essential to prevent a shift of disease into older age groups.