On January 27, 1999, the Food and Drug Administration initiated a voluntary recall of Tripedia diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP), lot number 0916490, manufactured by Pasteur Merieux Connaught USA. Routine post-release stability testing completed in January 1999 indicated that the potency of the diphtheria toxoid component of this lot was below specification. The potency of the tetanus and pertussis components of this lot was acceptable. (+info)
Childhood immunization coverage in zone 3 of Dhaka City: the challenge of reaching impoverished households in urban Bangladesh.
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A household survey of 651 children aged 12-23 months in Zone 3 of Dhaka City carried out in 1995 revealed that 51% of them had fully completed the series of childhood immunizations. Immunization coverage in slum households was only half that in non-slum households. Apart from residence in a slum household, other characteristics strongly associated with the completion of the entire series of childhood immunizations included the following: educational level of the mother, number of children in the family household, mother's employment status, distance from the nearest immunization site, and number of home visits from family-planning field workers. The findings point to the need to improve childhood immunization promotion and service delivery among slum populations. Two promising strategies for improving coverage are to reduce the number of missed opportunities for immunization promotion during encounters between health workers and clients, and to identify through visits to households those children who need additional immunizations. In the long run, increasing the educational level of women will provide a strong stimulus for improving childhood immunization coverage in the population. (+info)
Serum IgG antibody responses to pertussis toxin and filamentous hemagglutinin in nonvaccinated and vaccinated children and adults with pertussis.
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Levels of IgG antibody to pertussis toxin (PT) and filamentous hemagglutinin (FHA) were measured in paired serum samples from 781 patients fulfilling at least one laboratory criterion for pertussis that was suggested by an ad hoc committee sponsored by the World Health Organization. The patients were participants or family members of participants in a double-blind efficacy trial of a monocomponent pertussis toxoid vaccine. Of 596 nonvaccinated children, 90% had significant (two-fold or more) rises in PT IgG and FHA IgG levels. Only 17 (32%) of 53 children previously vaccinated with three doses of pertussis toxoid had rises in PT IgG levels because they already had elevated PT IgG levels in their acute-phase serum samples. PT IgG and FHA IgG levels were significantly higher in acute-phase serum samples from 29 adults than in acute-phase serum samples from the nonvaccinated children. Nevertheless, significant rises in levels of PT IgG (79% of samples) and FHA IgG (90%) were demonstrated in adults. In conclusion, assay of PT IgG and FHA IgG in paired serum samples is highly sensitive for diagnosing pertussis in nonvaccinated individuals. Assay of PT IgG levels in paired sera is significantly less sensitive for diagnosis of pertussis for children vaccinated with pertussis toxoid. (+info)
Evidence of efficacy of the Lederle/Takeda acellular pertussis component diphtheria and tetanus toxoids and pertussis vaccine but not the Lederle whole-cell component diphtheria and tetanus toxoids and pertussis vaccine against Bordetella parapertussis infection.
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A subanalysis of a recent cohort efficacy trial of a pertussis vaccine was performed to determine its efficacy against cough illnesses due to Bordetella parapertussis infections. Infants received four doses of either the Lederle/Takeda acellular pertussis component diphtheria and tetanus toxoids and pertussis (DTaP) vaccine or the Lederle whole-cell component diphtheria and tetanus toxoids and pertussis (DTP) vaccine at 3, 4.5, 6, and 15-18 months of age; controls received three doses of diphtheria and tetanus toxoids (DT) vaccine only. All subjects were prospectively followed for cough illnesses of > or = 7 days' duration; cases of B. parapertussis infection were confirmed by positive culture, household contact, or serology. Seventy-six cough illnesses due to B. parapertussis were identified; 24 occurred in 929 DTaP recipients, 37 in 937 DTP recipients, and 15 in 321 DT recipients, resulting in an efficacy of 50% for DTaP vaccine (95% CI [confidence interval], 5% to 74%) and 21% for DTP vaccine (95% CI, -45% to 56%). The data in the present analysis suggest that the Lederle/Takeda DTaP vaccine but not the Lederle whole-cell component DTP vaccine has efficacy against B. parapertussis infection. (+info)
Severe apnoeas following immunisation in premature infants.
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Four premature infants developed apnoeas severe enough to warrant resuscitation after immunisation with diphtheria, pertussis, and tetanus (DPT), and Haemophilus influenzae B (Hib). One required re-intubation and ventilation. Although apnoeas after immunisation are recognised, they are not well documented. It is time for further research to elucidate the best time to immunise such infants. (+info)
The induction of immunologic memory after vaccination with Haemophilus influenzae type b conjugate and acellular pertussis-containing diphtheria, tetanus, and pertussis vaccine combination.
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The significance of reduced antibody responses to the Haemophilus influenzae type b (Hib) component of acellular pertussis-containing combination vaccines (DTaP-Hib) is unclear. A DTaP-Hib vaccine evaluated in infants vaccinated at ages 2, 3, and 4 months showed reduced anti-Hib polysaccharide IgG (geometric mean concentration [GMC], 1.23 microgram/mL; 57%, >1.0 microgram/mL). Polyribitolribosyl phosphate (PRP) and Hib conjugate (PRP-T) vaccine given as a booster during the second year of life was evaluated for the presence of immunological memory. After boosting, most children achieved anti-PRP IgG >1.0 microgram/mL, although the GMC was higher with PRP-T (88.5 microgram/mL) than with PRP vaccine (7.86 microgram/mL, P<.001). The GMC of the PRP group was higher than anticipated for naive PRP recipients of the same age. PRP-specific IgG avidity was significantly higher after boosting than after priming, providing further evidence for the generation of memory. Despite reduced immunogenicity, DTaP-Hib combination vaccines appear to prime for immunologic memory. (+info)
A minimally invasive tracer protocol is effective for assessing the response of leucine kinetics and oxidation to vaccination in chronically energy-deficient adult males and children.
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In disadvantaged populations, recurrent infections lead to a loss of body nitrogen and worsen nutritional status. The resulting malnutrition, in its turn, produces a greater susceptibility to infection. This study aimed to examine the ability of a new minimally invasive tracer protocol to measure leucine oxidation, and then to use it to quantify the effect of vaccination on leucine kinetics and oxidation. Undernourished men (n = 5; body mass index 16.3 +/- 0.9 kg/m(2)) and children (n = 9; age 4.1 +/- 0.6 y; weight-for-age Z-score -2.3 +/- 0.7) underwent metabolic studies 6 d before and 1 d after vaccination with diphtheria, pertussis and tetanus (DPT). The tracer protocol was performed in the fed state and involved two 3-h sequential periods of frequent (20 min) oral doses of NaH(13)CO(3) or [1-(13)C] leucine. Frequent breath samples and urine collections were made. Blood samples were obtained from the men and used for the determination of the isotopic enrichment of alpha-ketoisocaproic acid. The prevaccination oxidation of leucine (percentage of dose +/- SD) was 18.1 +/- 2.3 (men) and 16.7 +/- 3.8 (children). One day after vaccination, these values had risen to 19. 9 +/- 1.9 (P < 0.05) in the men and to 19.5 +/- 4.6 (P < 0.01) in the children. In the adults, vaccination was associated with a rise in whole-body protein breakdown [mg protein/(kg.h)] from 200 +/- 40 to 240 +/- 10 (P < 0.05). A minor simulated infection increases leucine catabolism in undernourished humans and this new, minimally invasive protocol is sufficiently sensitive to measure these changes. (+info)
Vaccination with pertussis toxin alters the antibody response to simultaneous respiratory syncytial virus challenge.
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Many bacterial toxins, including pertussis toxin (PT), exert potent adjuvant effects on antibody synthesis to coadministered antigens. In these studies, we examined whether locally or peripherally administered PT similarly altered the antibody isotype selection to replicating virus after intranasal (inl) challenge. Mice primed intramuscularly with PT and inl with respiratory syncytial virus (RSV) produced RSV-specific antibodies of the IgG2a isotype at a level similar to that of unprimed controls, with some increase in IgG1 production. Mice primed inl with both PT and RSV showed elevated RSV-specific IgG1, increased serum IgE levels, and increased interleukin (IL)-4 in lung supernatants. Splenocytes from these animals produced increased IL-4 when stimulated in vitro with RSV or PT antigens after infection. These results suggest that PT can influence the local production of IL-4 to alter the humoral and cellular immune responses to viral infection as well as to coadministered antigens. (+info)