Protective effect of acellular pertussis vaccines.

Two acellular pertussis vaccines, a mono-component toxoid of pertussis toxin and a two-component vaccine containing both the toxoid and filamentous haemagglutinin, were used for primary immunization of infants 5 1/2 to 10 months of age in two clinical trials in Sweden. Over a follow-up period of 12 to 17 months, 37 children were exposed to pertussis in the household or a daycare centre. Only one child developed mild, culture-confirmed pertussis as opposed to the expected number of 30 to 33 cases based on an assumed attack rate of 80-90% in non-immunized children. These preliminary findings indicate that, given as primary immunization to infants, the vaccines provide protection against pertussis.

Salbutamol by powder or spray inhalation in childhood asthma.

Forty-three children from 3-16 years of age suffering from moderate bronchial asthma completed a double-blind cross-over study on the clinical effect of inhaled salbutamol (Ventoline) powder (0.2 mg/dosis) compared with spray (0.1 mg/dosis) over two 4-week periods. Both administrations gave significant improvement in air flow meter (AFM) results. There was no significant difference between the periods on active powder or spray regarding daily symptom scores, adjuvant medication or AFM values. The powder caused cough in four children but in 12 of 28 children it was considered as easy or easier to accept as the spray; nine of these 12 children were younger than 10 years of age. It is concluded that salbutamol inhaled as a powder is a useful alternative when using a spray is difficult or unwanted.

Spontaneous labor and elective induction--a prospective randomized study. I. Effects on mother and fetus.

In a prospective randomized study spontaneous and oxytocin induced labor "for convenience" have been compared with respect to uterine activity, duration of labor, the condition of the fetus and the newborn infant. The study consists of 84 normal patients, of whom 43 were induced at full term by amniotomy and oxytocin infusion using the Cardiff Infusion System Mark II; 41 patients served as controls. No difference in maternal age, number of previous pregnancies and pelvic score one week before the day of delivery were found between the groups. The following parameters were calculated: duration of labor, uterine activity, amount of bleeding in the third stage of labor, number of early and late decelerations as well as number of episodes of bradycardia in the CTG-recordings, birth weight, Apgar score one and five minutes post-delivery and blood gases in mother and child 60 seconds after delivery. No significant differences between the two groups were found. It is concluded that there are no increased risks to mother or fetus compared to normal labor provided that there is cephalic presentation and normal pregnancy, careful selection with respect to the length of pregnancy and the condition of the cervix and that the Cardiff infusion system is used with intrauterine pressure recording and continuous fetal heart monitoring.

Spontaneous labour and elective induction--a prospective randomized study. Behavioural assessment and neurological examination in the newborn period.

The effect of induction of labour on the foetus and the newborn was investigated in a prospective randomized study. 41 neonates were studied after induction at full term by amniotomy and intravenous oxytocin infusion. The infusion rate was regulated by the intraamniotic pressure using the Cardiff infusion pump system. 39 neonates served as controls where the labour started spontaneously followed by amniotomy. In both groups foetal heart rate monitoring intraamniotic pressure recordings were performed. There were no differences in Apgar score and pH in cord blood between the groups. The newborns were evaluated the first and the fifth day of life with the Brazelton Neonatal Behavioral Assessment Scale and with a modified Prechtl neurological examination. There were no differences in behaviour and neurological state between the two groups. However, within the groups there were significant differences between the first and the fifth day concerning both neonatal behaviour and neurological state.

Immunoglobulin E and G responses to pertussis toxin after booster immunization in relation to atopy, local reactions and aluminium content of the vaccines.

The role of aluminium for IgG and IgE responses to pertussis toxin (PT), as well as for side effects, was investigated in 49 children with known atopy status. Primary immunization had been given with an adsorbed monocomponent or an adsorbed two-component acellular pertussis vaccine. The children were then randomized to receive a booster immunization with either aluminium-adsorbed or non-adsorbed, whole cell, pertussis vaccine. Both vaccines induced good IgG responses with the adsorbed vaccine giving higher post-booster levels (p < 0.05). The adsorbed vaccine was, however, associated with more local side effects (p < 0.05) and tended to induce higher PT-IgE responses than the non-adsorbed vaccine. Furthermore, individuals who had received the two-component vaccine as primary immunization had higher PT-IgE responses after the booster, compared with individuals initially receiving the monocomponent vaccine (p = 0.041). No correlation between PT-IgE and PT-IgG levels was seen in any of the groups. Total serum IgE levels correlated to PT IgE levels, particularly in children with atopy (r = 0.950, p < 0.001). The addition of aluminium to the pertussis vaccine, was, thus, associated with a stronger IgG antibody response, but tended also to induce a stronger IgE antibody response. The correlation between total IgE and PT-IgE, which was most prominent in children with atopy, indicates that the role of immunization for the development of allergy merits further studies.

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).

Immunoglobulin E response to pertussis toxin in whooping cough and after immunization with a whole-cell and an acellular pertussis vaccine.

Immunoglobulin E antibodies to pertussis toxin (PT-IgE) were demonstrated in 15 of 23 (65%) patients with culture-confirmed pertussis. In 6 individuals there was a low-grade PT-IgE response after 6-9 weeks of disease and in 9 a rapid PT-IgE response, appearing 1-3 weeks after onset of symptoms. The PT-IgE antibody levels in immunized individuals were higher than in the non immunized. Following primary immunization of 23 children with a monovalent whole-cell pertussis vaccine (Burroughs-Wellcome, UK) or with an acellular pertussis vaccine (JNIH-6, Biken, Japan) a late low-grade PT-IgE response was found in 8 (35%). In 7/10 children previously immunized with the JNIH-6, a booster injection 16 months later with the same vaccine resulted in a rapidly appearing PT-IgE antibody response. In contrast, none of 13 children initially immunized with the monovalent whole-cell vaccine and then boostered with either this vaccine or JNIH-6 had detectable PT-IgE antibodies after the booster injection. The study shows that IgE-antibodies to pertussis toxin commonly appear in patients with whooping cough and that the kinetics and the magnitude of the response is influenced by previous exposure to the antigen. A PT-IgE response may also follow pertussis immunization.

Immunoglobulin E and G responses to pertussis toxin in children immunised with adsorbed and non-adsorbed whole cell pertussis vaccines.

The IgE and IgG responses to pertussis toxin were measured in blood samples from 70 children (age 1.5-2.9 years) after primary immunisation with either a non-aluminium adsorbed, whole cell vaccine (n = 34) or an aluminium adsorbed whole cell vaccine (n = 36). Two years later, they received a booster immunisation with either the non-adsorbed (n = 24) or the aluminium adsorbed vaccine (n = 14). Neutralising antibodies to pertussis toxin were higher (P < 0.05) after the three priming doses of the adsorbed vaccine than of the non-adsorbed vaccine, although both groups showed > 90% seropositives after the third dose. IgE antibodies to PT (PT-IgE) were detected in samples from 11/52 children after completed primary immunisation and the levels were low (median < or = 0.1 PRU ml-1) in both groups. No significant differences between the groups were found. PT-IgE levels did not increase after the booster injection. Thus, the aluminium content of the whole cell vaccines influenced the IgG response but not the IgE responses to pertussis toxin. The high rates of PT-IgE responses noted after a booster dose of acellular or whole cell pertussis vaccine to children primed with acellular vaccine in previous studies can therefore be mainly ascribed to the nature of the priming vaccine rather than the aluminium adjuvant.

Spontaneous labor and elective induction--a prospective randomized study. II. Bilirubin levels in the neonatal period.

The effect of induction of labor on the neonatal bilirubin levels was investigated in a prospective randomized study. Forty-three infants born after elective induction with oxytocin using the Cardiff infusion system and 38 infants born after spontaneous delivery were studied. Several factors other than oxytocin administration which could influence the bilirubin levels such as gestational age, placental transfusion and feeding routines did not differ between the two groups. There were no differences with regard to pH in umbilical vein. Apgar scores, haemoglobin and erythrocyte volume fractions of bilirubin levels neonatally. Thus there was no evidence of an association between induction of labor with oxytocin and jaundice during the neonatal period.