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P Olin

Publications and source records attributed to P Olin.

At least 37 records · Page 2Linked to original sources
PubMed1997

Randomised controlled trial of two-component, three-component, and five-component acellular pertussis vaccines compared with whole-cell pertussis vaccine. Ad Hoc Group for the Study of Pertussis Vaccines.

BACKGROUND: Trials in Italy and Sweden showed high efficacy for three-component and five-component pertussis vaccines, and poor efficacy for a whole-cell vaccine licensed in the USA and a two-component vaccine. We compared the efficacy of three acellular vaccines with a UK whole-cell vaccine. METHODS: We enrolled 82,892 babies aged 2-3 months. Babies were vaccinated at age 3 months, 5 months, and 12 months, or age 2 months, 4 months, and 6 months. They were randomly assigned a two-component acellular diphtheria-tetanus-pertussis (DTP) vaccine (n = 20,697), a three-component acellular DTP vaccine (n = 20,728), a five-component acellular DTP vaccine (n = 20,747), or a UK whole-cell DTP vaccine (n = 20,720). We collected data for all reported cases of culture-confirmed pertussis during 3 years of follow-up. The treatment status of the two-component-vaccine group had to be made known midway through the trial for boosting because of poor efficacy. We included data for the two-component vaccine in the analysis of safety and immunogenicity, and data up its unmasking in secondary analyses of relative efficacy. Analyses were by intention to treat. FINDINGS: During follow-up from the third dose (mean 22 months), in the 3 months, 5 months, 12 months schedule, there were 15 cases of culture-confirmed pertussis with at least 21 days of paroxysmal cough in the whole-cell group, relative risk 1.00, compared with 13 in the five-component group (0.85 [95% CI 0.41-1.79]), and 21 in the three-component group (1.38 [0.71-2.69]). For culture-confirmed pertussis, with or without cough, there were 19 cases in the whole-cell group (1.00). 27 in the five-component group (1.40 [0.78-2.52]), and 49 in the three-component group (2.55 [1.50-4.33]). In the intention-to-treat analyses, from the first dose in the 3 months, 5 months, 12 months schedule the whole-cell vaccine was significantly more protective than the three-component vaccine against typical pertussis. Between the second and the third doses, culture-confirmed pertussis with any cough and with at least 21 days of paroxysmal cough was significantly more frequent in the two-component group than in the three-component group, and in the three-component group than in the five-component and the whole-cell groups, respectively. The serological response of the acellular vaccines in the 2 months, 4 months, 6 months schedule were similar to those previously reported. The whole-cell vaccine was highly immunogenic for fimbriae, pertactin, and filamentous haemagglutinin, but had a low antipertussis toxin response. Hypotonic hyporesponsiveness occurred significantly more frequently in the whole-cell group (p < 0.05) and was more frequent in the acellular groups than previously reported. High fever and seizures occurred more frequently after whole-cell vaccine than after any of the acellular vaccines (p < 0.001). INTERPRETATIONS: The efficacy of the UK whole-cell vaccine and the five-component and three-component vaccines was similar against culture-confirmed pertussis with at least 21 days of paroxysmal cough. The lower efficacy of the three-component vaccine against mild disease suggests that fimbriae have a role in protection against infection. The efficacy of acellular vaccines depends on the number of components, and different whole-cell vaccines have variable efficacies.

Antibody Formation↗
PubMed1997

Severe adverse events in the Italian and Stockholm I pertussis vaccine clinical trials.

The rates of severe side reactions observed in Stockholm I and Italian Trials are reported. Children vaccinated with the same DTPwc in both trials experienced high fever and persistent crying more frequently than in any other group, while similar rates for all the severe side reactions were observed among DTaPs and DT vaccines. Recipients of different DTaP vaccines showed similar rates of severe reactions, which did not differ from recipients of DT vaccines, either in Sweden or Italy.

Child, Preschool↗
PubMed1997

Common side effects in the Italian and Stockholm I trials.

We have compared the frequency of common side effects observed following vaccination in the Italian and Stockholm I Trials. A higher proportion of DTPwc vaccinees in the two trials experienced side effects compared with DTaP and DT vaccinees. Fever, local redness and tenderness were more frequently observed in all study groups in the Stockholm I Trial when compared to the Italian Trial. Despite the similarities in study design, parental recall bias, site of injection, simultaneous administration of other vaccines, and antipyretic use could have played a role in the differences observed.

Diphtheria Toxoid↗
PubMed1996

A controlled trial of a two-component acellular, a five-component acellular, and a whole-cell pertussis vaccine.

BACKGROUND: Because of concern about safety and efficacy, no pertussis vaccine has been included in the vaccination program in Sweden since 1979. To provide data that might permit the reintroduction of a pertussis vaccine, we conducted a placebo-controlled trial of two acellular and one whole-cell pertussis vaccines. METHODS: After informed consent was obtained, 9829 children born in 1992 were randomly assigned to receive one of four vaccines: a two-component acellular diphtheria-tetanus-pertussis (DTP) vaccine (2566 children), a five-component acellular DTP vaccine (2587 children), a whole-cell DTP vaccine licensed in the United States (2102 children), or (as a control) a vaccine containing diphtheria and tetanus toxoids (DT) alone (2574 children). The vaccines were given at 2, 4, and 6 months of age, and the children were then followed for signs of pertussis for an additional 2 years (to a mean age of 21/2 years). RESULTS: The whole-cell vaccine was associated with significantly higher rates of protracted crying, cyanosis, fever, and local reactions than the other three vaccines. The rates of adverse events were similar for the acellular vaccines and the control DT vaccine. After three doses, the efficacy of the vaccines with respect to pertussis linked to a laboratory-confirmed case of pertussis or contact with an infected household member with paroxysmal cough for > or = 21 days was 58.9 percent for the two-component vaccine (95 percent confidence interval, 50.9 to 65.9 percent), 85.2 percent for the five-component vaccine (95 percent confidence interval, 80.6 to 88.8 percent), and 48.3 percent for the whole-cell vaccine (95 percent confidence interval, 37.0 to 57.6 percent). CONCLUSIONS: The five-component acellular pertussis vaccine we evaluated can be recommended for general use, since it has a favorable safety profile and confers sustained protection against pertussis. The two-component acellular vaccine and the whole-cell vaccine were less efficacious.

Antibodies, Bacterial↗
PubMed1995

Defining surrogate serologic tests with respect to predicting protective vaccine efficacy: pertussis vaccination.

The first efficacy trial of pertussis vaccines with defined purified antigens failed to demonstrate a serologic correlate of protection, although both tested vaccines were shown to give significant protection against typical whooping cough. The antibody response to pertussis toxoid was dose dependent. A lower anti-PT response in the two-component vaccine, containing one-half the amount of PT in the one-component vaccine, seemed to be compensated by a significant anti-FHA response, since both vaccines conferred similar protection against typical illness. However, the immunologic mechanisms whereby protection is conferred remain unclear. At present antibody responses to the antigens included in the first tested vaccines could be used as pseudoindicators of protection. The group of vaccinated infants who were protected did differ in their antibody profile as compared to unvaccinated infants. Tentatively, candidate vaccines should elicit no less antibody responses to PT and FHA as those elicited by the above one- and two-component vaccines, respectively. The response to other antigens such as pertactin and fimbriae cannot be related to protection at present. Ongoing efficacy trials of a number of pertussis vaccines of varying composition may or may not provide immunological correlates of protection against pertussis. The trials ought to be subjected to a preplanned, independent (meta)analysis with defined end points to increase the understanding of the contribution of various antigens to the protective efficacy of pertussis vaccines.

Antibodies, Bacterial↗
PubMed1995

Acellular pertussis vaccines--a question of efficacy.

Whole cell pertussis vaccine is considered to offer at least 80% protection against typical whooping cough. The quest for an equally effective but less reactogenic vaccine is now drawing to a close. During the forthcoming year a number of efficacy trials of acellular pertussis vaccines will be terminated. A variety of vaccines containing one, two, three or five purified pertussis antigens are being tested in Germany, Italy, Senegal and Sweden. About 30,000 infants have been enrolled in placebo-controlled studies and more than 100,000 in whole cell vaccine-controlled trials. The final plans for analysis of a Swedish placebo-controlled trial of whole cell and acellular vaccines is presented. Due to the unexpected high incidence of pertussis in Sweden during 1993-1994, relative risk comparisons between vaccines will be attempted in that trial, in addition to estimating absolute efficacy. A crucial issue is to what extent data may be compared between trials, given differences in design, vaccination schedules, and chosen endpoints. A primary case definition of laboratory-confirmed pertussis with at least 21 days of paroxysmal cough have been adopted in most trials. Pre-planned meta-analysis using this single endpoint will facilitate comparisons between vaccines. Serological correlates to protection in individuals will be sought in the ongoing placebo-controlled trials. The concept of a serological correlate valid for a vaccinated population but not necessarily for the vaccinated individual, as is the case with Hib vaccines, may turn out to be the only alternative to performing large efficacy trials in the future.

Child, Preschool↗
PubMed1994

An international perspective on child day-care health.

If we are committed to the health and development of children, we need to recognize that the vast majority of the world's women are working women. In Africa, 80% of the women are actively engaged in economic activities outside the home. The "economic miracle" in Southeast Asia was made possible by the nimble fingers of thousands of women working in textile and electronics factories. There is need for pre-day-care advocacy for infants, through promotion of breast feeding and maternity leave. When the mother returns to work, the standard of the International Labor Organization should be applied, namely" ...the care of children while the parents are working cannot be ignored because it forms a focal point on which three main concerns of development policy--work, health, and education--converge." Several principles emerged from the presentations in the international panel: 1. Child-care programs must be community based, using the resources of the families and the community organizations themselves. 2. Programs require the active involvement of the communities, women's groups, and other partners. 3. Programs are modified by innovations created by community organizations, universities, and other groups. 4. Programs require the mobilization of trained young men and women into the field of early childhood education and development. This international panel provided an overall uniting theme, that throughout the world the hope for the survival and better life for children unites parents of every country and every creed. This is one of the most powerful and strongest motivational resources in the world.(ABSTRACT TRUNCATED AT 250 WORDS)

Canada↗
PubMed1993

Comparison of nasopharyngeal aspirates with swabs for culture of Bordetella pertussis.

Nasopharyngeal samples were collected from 117 children by aspiration from one nostril and by swab from the other one and cultured for Bordetella pertussis. Among 33 culture-positive specimens, there were 30 positive aspirates and 26 positive swab specimens. Aspirates are easily divided and saved for investigations with other assays which may further improve diagnostic sensitivity. As the aspiration technique was also preferred by nurses and parents, it was recommended and chosen for a planned pertussis vaccine efficacy trial to take place in Sweden from 1992 to 1995.

Adolescent↗
PubMed1992

Relative efficacy of two acellular pertussis vaccines during three years of passive surveillance.

Prolonged unblinded passive surveillance of the trial cohort from the Swedish 1986-87 pertussis vaccine efficacy trial indicates that a two-component vaccine, containing pertussis toxoid and filamentous haemagglutinin, provided better long-term protection against pertussis than a monocomponent pertussis toxoid vaccine. The relative risk (RR) for culture-confirmed pertussis was 1.5 (95% confidence interval (CI) 1.0-2.4), and RR for pertussis according to parents' diagnoses was also 1.5 (95% CI 1.1-2.1), for the monocomponent vaccine compared with the two-component vaccine.

Female↗
PubMed1991

Acellular pertussis vaccines. Efficacy and evaluation of clinical case definitions.

The efficacy of two acellular pertussis vaccines was estimated for various clinical case definitions, with and without the requirement of culture confirmation, from a randomized trial in Sweden. Efficacy increased with duration of coughing spasms and when the case definition included whoops or whoops plus at least nine coughing spasms a day. After deletion of clinical cases not believed to be caused by pertussis, efficacies were closer to the higher values for culture-confirmed disease. Nonspecificity of the clinical criterion "21 days of coughing spasms with whoops" resulted in estimates of predictive value for pertussis of 85% for placebo recipients and 56% for vaccinees. We conclude that laboratory confirmation of suspected cases is needed in pertussis vaccine trials. A suggested case definition is 21 days or more of coughing spasms with confirmation by culture, serologic study, or household exposure to culture-confirmed pertussis.

Humans↗
PubMed1991

The Swedish efficacy trial of acellular pertussis vaccines--update and time for reflection.

The trial cohort from the Swedish efficacy trial conducted during 1986-1987 is still under non-blinded surveillance. During post-trial follow-up until March 11, 1990, efficacy of the mono-component vaccine, JNIH-7, was estimated to be 65% (95% confidence interval, CI, 49-76%) and the efficacy of the two-component vaccine, JNIH-6, to 77% (95% CI 64-85%). For culture-confirmed cases with more than 30 days of cough efficacy for JNIH-7, was 79% (95% CI 66-87%) and for JNIH-6, 92% (95% CI 83-96%). The data indicate that two doses of acellular pertussis vaccine provide protection for 3 1/2 years or more. Continued analysis of data from the trial suggests that acellular pertussis vaccines protect against typical illness to the same extent as whole cell vaccines and that protection against infection may be augmented by adding one or more components to a pertussis toxoid-based vaccine. In spite of promising efficacy data, acellular pertussis vaccines are still not licensed outside Japan. The need for direct comparisons with efficacy and safety of whole cell vaccines will be discussed and salient problems of case definitions and case ascertainment in clinical trials will be emphasised.

Child↗