PubMed Health⌕ Search

Biomedical subjects

P Olin

Publications and source records attributed to P Olin.

At least 19 recordsLinked to original sources
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↗
PubMed1990

Secondary analyses of the efficacy of two acellular pertussis vaccines evaluated in a Swedish phase III trial.

A placebo-controlled efficacy trial of two acellular pertussis vaccines carried out in Sweden in 1986-87 used culture confirmation as the principal case definition. However, the sensitivity of pertussis culture is low, and secondary analyses using more sensitive serological diagnostic criteria have therefore been carried out. These analyses confirm that vaccination with pertussis toxoid alone does protect against typical whooping cough with laboratory confirmation, but show that it does not protect against infection or colonization. There is evidence that the addition of filamentous haemagglutinin provides some protection against infection. Bacterial isolation rates were lower in vaccinated than unvaccinated children with serologically confirmed pertussis and increased with disease severity.

Child↗
PubMed1988

Protective efficacy of a whole cell pertussis vaccine.

A trial of the efficacy of a plain whole cell pertussis vaccine was conducted in Sweden. In this non-blinded trial 525 infants aged 2 months who were born on days with an even number received three doses of vaccine one month apart and 615 infants of the same age who were born on days with an odd number were enrolled as controls. During the 18 months of follow up there were 55 cases of pertussis. The attack rate was 1.5% (8/525) among the vaccinated children and 7.6% (47/615) among the unvaccinated children (p less than 0.001). The estimated efficacy of the vaccine was 80% (95% confidence interval 58 to 90). The estimated efficacy of pertussis vaccine was similar to that observed in British trials over 30 years ago.

Clinical Trials as Topic↗
PubMed1988

Mortality and morbidity from invasive bacterial infections during a clinical trial of acellular pertussis vaccines in Sweden.

A double blind placebo-controlled efficacy trial of two acellular pertussis vaccines was conducted in 3801 6- to 11-month-old children. Four vaccinated children died during 7 to 9 months follow-up as a result of Haemophilus influenzae type b meningitis, heroin intoxication with concomitant pneumonia, suspected septicemia, and Neisseria meningitidis Group B septicemia. From the actual death rate in children belonging to the same birth cohort in Sweden that could have been eligible for the trial, one death was expected among vaccinated children. Several investigations were carried out to examine the possibility that the deaths could be causally related to the vaccination. The relative risk for hospitalization due to systemic or respiratory infections was 1.07 (95% confidence interval, 0.95 to 1.20) and 0.83 (95% confidence interval, 0.64 to 1.08) in the vaccine groups as compared with the placebo group. Subsets of the population were studied for signs of immunosuppression. There was no indication of immunoglobulin deficiency or any sign of clinically significant leukopenia or lymphocytosis in vaccine recipients. The results of this analysis provide no evidence for a causal relation between vaccination with the studied acellular pertussis vaccines and altered resistance to invasive disease caused by encapsulated bacteria. The hypothesis that the two variables are related, however, cannot be refuted from these data.

Antibodies, Bacterial↗
PubMed1988

Primary immunization of infants with an acellular pertussis vaccine in a double-blind randomized clinical trial.

The rate of adverse reactions and the immunogenicity of a two-component acellular pertussis vaccine as compared with a plain whole-cell vaccine and a placebo were evaluated for primary immunization in 319 6-month-old infants in a double-blind randomized clinical trial. The acellular vaccine produced few and mild systemic and local reactions. Fever (greater than or equal to 38 degrees C) occurred in 6% to 8% of acellular vaccinees as opposed to 25% to 37% of whole-cell vaccinees. Redness (greater than or equal to 1 cm) appeared in 2% to 13% of the acellular vaccine and 24% to 32% of the whole-cell vaccine recipients. Antibody response to pertussis toxin measured in a neutralization test was obtained in 97% to 100% of the infants receiving either two or three doses of the acellular vaccine as compared to 59% after three doses of whole-cell vaccine.

Antitoxins↗
PubMed1988

Invasive bacterial infections during an efficacy trial of acellular pertussis vaccines--implications for future surveillance in pertussis vaccine programmes.

During a placebo controlled trial of acellular pertussis vaccines a cluster of invasive bacterial infections with fatal outcome occurred among vaccinated children as compared with unvaccinated Swedish children of the same birth cohort (4). Clinical and immunological studies did not support the hypothesis of an immunosuppressive effect of the vaccines, which would explain the deaths, but the hypothesis could not be refuted by the data. To evaluate the safety of acellular pertussis vaccines regarding rare severe events--in particular invasive infectious diseases--prospective studies seem to be needed, comparing very large groups. A coordinated and controlled vaccine programme during 1-2 years in most of Sweden combined with national reports of invasive infections may serve as a basis for such a study. A possible study design is given below.

Bacterial Infections↗
PubMed1987

A clinical trial of a monocomponent pertussis toxoid vaccine.

We compared a monocomponent pertussis toxoid vaccine preparation (JNIH-7) in a double-blind, randomized study with another component vaccine (JNIH-6) containing pertussis toxoid and filamentous hemagglutinin in equal proportions. Monocomponent pertussis toxoid vaccines have not been tested previously in children. This trial comprised 255 previously nonimmunized children 6 to 10 months old who were given two 0.5-mL subcutaneous injections of either vaccine four to five weeks apart. Prevaccination and postvaccination serum samples from 235 infants showed an antitoxin seroconversion rate of 100% in both groups. Adverse reactions were few and mild, with local reactions occurring more often after administration of the second dose and among recipients of the two-component vaccine (P less than .05).

Antibody Formation↗
PubMed1986

Preliminary data from a clinical trial (phase 2) of an acellular pertussis vaccine, J-NIH-6.

In the search for a new and better pertussis vaccine for general vaccination in Sweden, a clinical trial of an adsorbed acellular vaccine from Japan has been performed. The vaccine used was produced by Biken and contained only F-HA and the toxoid of pertussis toxin (LPF). The aims were: To demonstrate the serological response to primary vaccination of this adsorbed acellular vaccine in comparison to a plain whole cell vaccine. To compare the incidence of side reactions between the two types of vaccines and the adjuvant (aluminium phosphate) of the acellular vaccine used as placebo.

Adjuvants, Immunologic↗
PubMed1979

Quality of care: a tracer diagnosis study of acute otitis media, comparing a district paediatric service with paediatric and otolaryngology emergency departments.

Acute otitis media was used as a tracer condition for comparing patient care as regards patient satisfaction, compliance and medical outcome in a district paediatric office, an otolaryngological and a paediatric hospital emergency department. The initial work-up of the 216 patients studied at the three units was in good agreement with predefined standards. However, while the district paediatrician arranged a follow-up for all patients, the hospitals did so only in 10--30% of the visits. Parent satisfaction was significantly higher at the district office when the time spent waiting and the time the patient was with the doctor were kept constant. Urinary penicillin was not detected in 1/17 of district paediatric and in 6/19 of otological patients. Compliance with follow-up was also much higher at the district paediatrician. Medical outcome did not differ between the units. The majority of the parents expressed preference for the type of care given in a neighbourhood service. It is suggested that the criteria for adequate treatment of acute otitis media adapted for emergency departments may be revised in case easy access is provided to a medical centre offering continuity of care and proper follow-up. Studies of the quality of care have so far not managed to demonstrate a definite and positive relationship between the process of care, patient satisfaction and final medical results.

Adult↗