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Biomedical subjects

A Anemona

Publications and source records attributed to A Anemona.

13 recordsLinked to original sources
PubMed2001

Reactogenicity and immunogenicity at preschool age of a booster dose of two three-component diphtheria-tetanus-acellular pertussis vaccines in children primed in infancy with acellular vaccines.

OBJECTIVES: To determine the reactogenicity and immunogenicity of a fourth dose of 2 three-component acellular pertussis vaccines combined with diphtheria-tetanus-acellular pertussis (DTaP) when administered at preschool age to children primed in infancy with 3 doses of the same DTaP and who had received a diphtheria-tetanus (DT) dose at the age of 12 months. SETTING: Local health units of 4 Italian regions. STUDY DESIGN: Three thousand five hundred twenty-two children, who had been randomized in the first year of life to be immunized with a DTaP vaccine by either SmithKline Beecham or Chiron Biocine, were offered a booster of the same vaccine or, if refusing, a DT vaccine at the age of 5 to 6 years. Families of children were aware of the vaccine administered. The occurrence of adverse events was compared between the children who received a DTaP booster and those boosted with a DT only. Antibody titers to pertussis vaccine components (pertussis toxin, filamentous hemoagglutinin, and pertactin) were determined on 558 paired sera taken before and 30 days after the DTaP booster administration. RESULTS: Four episodes of temperature >/=39.5 degrees C, 2 in each DTaP group, were recorded. Fever >/=38 degrees C occurred infrequently in both DTaP and DT recipients (DTaP range: 2.5%-2.8%; DT range: 0%-4.8%), as did irritability (DTaP range: 10.1%-11.7%; DT range: 7.4%-12.6%). The frequency of local reactions was significantly higher for DTaP recipients (range: 44.0%-52.8%), with respect to DT recipients (range: 29.5%-44.4%). Extensive local reactions were observed in 1.2% of DTaP recipients and in.5% of DT recipients. Both DTaP vaccines induced high antibody titers against pertussis toxin, filamentous hemoagglutinin, and pertactin, with an increase of >10 times the prebooster geometric mean titers. CONCLUSIONS: A booster dose of DTaP at preschool age in children primed with the same acellular pertussis vaccine is safe and immunogenic. However, the frequency of local reactions is higher compared with that following primary immunization and with that following booster with DT only, and parents should be informed of the potential for these reactions to occur.

Child↗
PubMed1999

Reactogenicity of a three-dose pertussis acellular vaccine catch-up in children 21-40 months of age.

The reactogenicity of a three-dose catch-up acellular pertussis (aP) immunization of children at 21-40 months of age was evaluated. Vaccination was well-tolerated: fever > or = 38 degrees C was reported after 5% of administered doses and local reactions after 14-15%. The onset of adverse events was not associated with age at vaccination, interval between doses or previous presence of antibodies against pertussis, whereas injection in sites other than the buttock and presence of the same symptom after a previous dose were associated with higher reactogenicity. Because of the good safety profile of primary aP immunization in children > 1 year of age, catch-up vaccination campaigns could be considered in areas where pertussis whole-cell vaccination uptake has been low and where the number of susceptible children should be reduced to control pertussis circulation.

Aging↗
PubMed1998

Persistence of protection through 33 months of age provided by immunization in infancy with two three-component acellular pertussis vaccines. Stage II Working Group.

A large, randomized, placebo-controlled clinical trial in Italy on two three-component pertussis vaccines, given as DTaP in infancy, one manufactured by SmithKline and Beecham (SB) and one by Chiron Biocine (CB), found each vaccine to be 84% efficacious through the average age of 24 months. The cohort of children enrolled in the trial was followed with unmodified case ascertainment procedures for nine additional calendar months, during which partial unblinding occurred, for the unvaccinated randomized group. For the DTaP groups, the specific vaccine assignment remained double-blinded throughout the entire additional observation period. Pertussis was defined as paroxysmal cough lasting at least 21 days and confirmed by culture or serology. In the additional 9 months the observed absolute efficacy was 78% (95% CI, 62-87%) for SB DTaP vaccine and 89% (95% CI, 79-94%) for CB DTaP. The relative risk of developing pertussis in SB DTaP recipients compared to CB DTaP vaccinees was 1.99 (95% CI, 1.13-3.51). By combining observations from the initial and additional follow-up periods, the overall observed vaccine efficacy through an average age of 33 months of SB DTaP was 80% and of CB DTaP, 85%.

Child, Preschool↗
PubMed1998

Bordetella parapertussis infection in children: epidemiology, clinical symptoms, and molecular characteristics of isolates.

The clinical trial conducted in Italy to evaluate the efficacy of acellular pertussis vaccines provided an opportunity to estimate the frequency of clinical infections with Bordetella parapertussis and to compare the clinical characteristics of children suffering from Bordetella pertussis illness with those of children with B. parapertussis illness. This study dealt with 76 B. parapertussis infections diagnosed from a population of 15,601 children participating in the follow-up of suspected cases of pertussis. An overall incidence of 2.1 cases of laboratory-confirmed parapertussis per 1,000 person-years was observed. Children affected by B. parapertussis infections showed a less severe clinical picture both in the duration of symptoms and in the percentage of patients affected, even when compared with vaccinated children with pertussis. To characterize the isolated strains, we performed assays for susceptibility to erythromycin and sulfamethoxazole-trimethoprim, and we examined the genomic DNAs by pulsed-field gel electrophoresis. The results showed a high degree of genetic stability among B. parapertussis strains regardless of time of collection and geographical distribution.

Bordetella↗
PubMed1997

Incidence of invasive Haemophilus influenzae type b disease in Italian children.

To estimate the incidence of Haemophilus influenzae type b (Hib) invasive disease in Italian infants we performed a prospective study in a cohort of newborns enrolled for a randomized trial on safety and efficacy of three pertussis vaccines and followed for onset of serious disease or pertussis. The overall cumulative incidence observed in 15,601 children was 51.3/100,000 for all invasive Hib infections and 38.4/100,000 for Hib meningitis, over 27 months of observation. The incidence density of all invasive Hib disease was 28.7/100,000 person-years, while meningitis occurred with an incidence of 21.5/100,000 person-years. Among the eight cases detected, six were meningitis, one sepsis, and one cellulitis. The child with sepsis died. The incidence and epidemiology of invasive Hib disease in Italy are comparable to those reported from other European countries. Cost-benefit analyses are needed for planning Italian vaccination policy.

Cohort Studies↗
PubMed1997

Case definitions.

The definition of a case of pertussis is an essential point in evaluating and comparing the results from the seven studies on pertussis vaccines presented at the Symposium. An assessment of the impact of case definition on the evaluation of vaccine efficacy has been performed on the Italian data-set, by comparing the clinical presentation of cough illnesses which were laboratory-confirmed as B. pertussis infection with those not-confirmed, by study vaccine. The results show that the estimate of vaccine efficacy is greatly variable by the choice of case definition and dependent on the study design. The assessment of the effect of each vaccine should be performed by using various clinical endpoints and the method used in detection of suspected cases in each study should be carefully evaluated to verify comparability of results.

Cough↗
PubMed1997

Differences by antigen in seroconversion: sensitivity, specificity and bias in the serological confirmation of pertussis.

Vaccine efficacy of the most efficacious acellular pertussis vaccines in the three recent placebo-controlled clinical trials, when estimated using the primary clinical case criterion, does not change substantially with the inclusion of serological confirmation in addition to culture confirmation. In the Italy trial, because of relatively high anti-PT antibody levels at the time of the acute-phase specimen in episodes of 21 or more days of paroxysmal cough, significant increases in antibody to PT are less likely to be seen in the acellular vaccine groups when evaluating children with bacterial isolation. However, the effect of this decreased sensitivity appears to be compensated by significant antibody increases in the FHA assay. When projecting a maximally sensitive criterion for serological assessment using the observed decreases in IgG antibody to PT over time following primary vaccination stratified by vaccine group, and comparing the expected antibody level with the observed level in the convalescent-phase specimen, the effect on estimated vaccine efficacy is minimal.

Antibodies, Bacterial↗
PubMed1996

A controlled trial of two acellular vaccines and one whole-cell vaccine against pertussis. Progetto Pertosse Working Group.

BACKGROUND: Concern about both safety and efficacy has made the use of whole-cell pertussis vaccines controversial. In some European countries, including Italy, the rate of vaccination against pertussis is low. METHODS: We conducted a double-blind trial in Italy in which infants were randomly assigned to vaccination at two, four, and six months of age with an acellular pertussis vaccine together with diphtheria and tetanus toxoids (DTP); a DTP vaccine containing whole-cell pertussis (manufactured by Connaught Laboratories); or diphtheria and tetanus toxoids without pertussis (DT). The acellular DTP vaccine was either one containing filamentous hemagglutinin, pertactin, and pertussis toxin inactivated with formalin and glutaraldehyde (SmithKline Beecham) or one with filamentous hemagglutinin, pertactin, and genetically detoxified pertussis toxin (Chiron Biocine). Pertussis was defined as 21 days or more of paroxysmal cough, with infection confirmed by culture or serologic testing. RESULTS: The efficacy of each vaccine, given in three doses, against pertussis was determined for 14,751 children over an average of 17 months, with cases included in the analysis if cough began 30 days or more after the completion of immunization. For both of the acellular DTP vaccines, the efficacy was 84 percent (95 percent confidence intervals, 76 to 89 percent for Biocine DTP and 76 to 90 percent for SmithKline DTP), whereas the efficacy of the whole-cell DTP vaccine was only 36 percent (95 percent confidence interval, 14 to 52 percent). The antibody responses were greater to the acellular vaccines than to the whole-cell vaccine. Local and systemic adverse events were significantly more frequent after the administration of the whole-cell vaccine. For the acellular vaccines, the frequency of adverse events was similar to that in the control (DT) group. CONCLUSIONS: The two acellular DTP vaccines we studied were safe, immunogenic, and efficacious against pertussis, whereas the efficacy of the whole-cell DTP vaccine was unexpectedly low.

Antibodies, Bacterial↗
PubMed1996

Predicting the accrual rate in a vaccine clinical trial: an a posteriori evaluation of the feasibility study.

To estimate the expected accrual rate in a double blinded controlled randomized trial of the absolute clinical efficacy of three anti-pertussis vaccines in infants, we performed a series of surveys among mothers and physicians in the areas to be considered for participation in the trial. In this paper, we compared the predicted enrollment with the actual enrollment achieved at the end of the recruitment phase of the trial. The predicted enrollment rate was 27%, while the observed rate was 26%. Results from the feasibility study were highly predictive of actual enrollment rate. In the local health units (USL) where such assessments were carried out, the accrual rate, was higher than those not participating in the feasibility phase.

Adult↗
PubMedDate not supplied

Predictors of adverse events after the administration of acellular and whole-cell diphtheria-tetanus-pertussis vaccines.

Recurrence of adverse events, the effect of site of injection, and concurrent administration of oral polio vaccine (OPV) and hepatitis B vaccine (HBV) on reactogenicity were assessed in recipients of two acellular pertussis vaccines given in combination with diphtheria and tetanus toxoids (DTaP), one whole-cell DTP vaccine (DTPwc) and one DT vaccine during a double blind, randomized, controlled clinical trial. Local and systemic side reactions were more likely to recur after the administration of DTaP and DT compared with DTPwc. In all vaccine groups, injection in the buttock was associated with a lower rate of common adverse events compared with injection in the thigh, while simultaneous administration of OPV and/or HBV did not increase the risk of onset of side reactions.

Diphtheria↗
PubMedDate not supplied

[Epidemiology of invasive infections with Haemophilus influenzae type b in the world and in Italy].

The incidence of Haemophilus influenzae type b (Hib) disease in the 0-5 years age group has been studied in many countries. In the United States, before the introduction of mass vaccination, the incidence of invasive Hib disease ranged from 7 per 100,000 in the 4-5 years age group to 452 pert 100,000 in the 6-11 months age group. In Europe, the incidence of this disease has been estimated to range from 21 to 60 per 100,000 per year in the 0-5 years age group. Hib infection is mainly transmitted by the respiratory route. Risk factors of the disease include: attending a day-care center, a high number of household members, low socio-economic level, age less than two years, and belonging to certain ethnic groups. Accurate estimates of the incidence of invasive Hib disease do not exist in Italy. Among the 15,601 children participating in the "Progetto Pertosse", a clinical trial for the evaluation of antipertussis vaccines, there occurred six cases of Hib meningitis, one of Hib sepsis, and one of Hib cellulitis. These episodes yield an incidence density of 28.7 per 100,000 person-years in the 2-30 month age group. Incidence data will also need to be collected for children in the 30 months-5 years age group before attempting a cost-benefit analysis with the aim of planning a mass vaccination.

Age Distribution↗