Roger M. Barkin

Response of preterm infants to diphtheria-tetanus-pertussis immunizations*

To establish guidelines for the routine use of diphtheria, tetanus, and pertussis (DTP) vaccine in preterm infants, we quantitated antibody responses of preterm infants to DTP and determined the nature and extent of side effects. Twenty-five preterm infants were immunized with 0.5 ml DTP vaccine at routine intervals. Term infants served as controls. Immediately before each immunization and 2 months after the third, DTP-specific antibodies were quantitated. Clinical side effects were determined by parental report. After the second immunization, 100% of preterm infants had evidence of specific antibody production against diphtheria, tetanus, and pertussis. The incidence of side effects was low, but irritability was significantly more common in preterm infants after the second immunization. These observations suggest that the initiation of primary immunization with DTP in preterm infants need not be delayed beyond 2 months of age.

Biliary atresia and the Kasai operation: Continuing care

Surgical intervention utilizing the Kasai hepatic portoenterostomy has improved the outcome of patients with biliary atresia and provided a population of patients with unique health problems. The clinical course of 21 children followed for three years or longer was reviewed, focusing on their medical management. Ten (47.6%) had successful bile drainage following surgery and experienced a number of specific problems including recurrent cholangitis, nutritional and growth deficiencies, delayed developmental landmarks, portal hypertension, osteomalacia and osteoporosis, and social and psychiatric difficulties. These complications responded to aggressive medical therapy and support. Although the overall three-year survival of this series was 38.1%, in children who were operated upon prior to 2 months of age and in whom the enteric conduit was externalized the three-year survival rate was 66.7%.

The limping child.

The limping child often presents to the emergency department with a nonspecific history and physical examination. The components of gait, the pathophysiology of specific abnormalities, and the conditions that may produce long-term morbidity must be identified expeditiously to assure return to normal function. Ancillary data and imaging may be essential for appropriate management.

Pediatric diphtheria and tetanus toxoids-adsorbed vaccine: immune response to the first booster following the diphtheria and tetanus toxoids vaccine primary series.

Diphtheria and tetanus toxoids (DT) vaccine should be given to children at 2, 4 and 6 months of age when there are contraindications to the administration of pertussis vaccine. We have previously reported that such children develop protective antitoxin antibody levels to diphtheria and tetanus antigens. This follow-up study evaluates the decay in antitoxin antibody levels and the booster response elicited to DT antigen when a fourth dose is given at approximately 18 months of age. Twenty-three children receiving DT vaccine were compared to 38 receiving diphtheria and tetanus toxoids-pertussis (DTP) vaccine. The prebooster antibody titer to diphtheria and tetanus at approximately 18 months of age had declined below the recommended protective level in one child who had received DT vaccine and in three children who had received DTP. Following the 18-month booster dose of DT and DTP vaccine, all of the children had protective titers to diphtheria and tetanus toxin. These results suggest that the adjuvant effects of pertussis vaccine are not required to achieve adequate immunization to diphtheria and tetanus when currently available DT vaccine is used in early childhood.

Primary immunization with diphtheria-tetanus toxoids vaccine and diphtheria-tetanus toxoids-pertussis vaccine adsorbed: comparison of schedules.

In a double blind study patients were randomly divided into two groups. All patients received an initial immunization with diphtheria-tetanus toxoids-pertussis (DTP) vaccine at 2 months of age. One population received diphtheria-tetanus toxoids (DT pediatric) vaccine at the time of the second immunization at 4 months of age and DTP vaccine at 6 months (DTP-DT-DTP). In a second group DTP vaccine was administered as the second immunization and DT (pediatric) vaccine was given at the 6-month visit (DTP-DTP-DT). There was a significantly increased incidence and severity of adverse reactions associated with DTP vaccine when contrasted with responses observed after DT vaccine; differences were apparent whether the vaccine was administered as the second or the third immunization. All patients had serologic evidence of protection to diphtheria and tetanus following completion of either primary series. The geometric mean titer of pertussis agglutinins was similar in the two study groups 2 months after the second DTP immunization but was significantly higher in the DTP-DT-DTP group at 1 to 2 months after the completion of the primary immunization series (P less than 0.01). Both groups, however, were significantly lower than the comparable geometric mean titer measured after a series of three DTP inoculations (7.51, log2) (P less than 0.01). This study supports the recommendation that three immunizations of DTP be administered in the first year of life.

512 HEMOPHILUS INFLUENZAE TYPE B(HIB) POLYSACCHARIDE VACCINE: SAFETY AND IMMUNOGENICITY OF PRP AND PRP-D CONJUGATE VACCINES IN CHILDREN 16|[ndash]|24 MONTHS

A multicenter study of the relative safety and immunogenicity of the purified heat-sized Hib polysaccharide (PRP) and conjugate (PRP-D) vaccines was conducted in 475 children 16-24 months of age. No serious reactions occurred in either group. Except for fewer febrile reactions in the PRP-D group (p<.05), other reactions were similar for both vaccines.Immune responses were measured by KIA (ug)ml and are summarized below:Although PRP is soon to be licensed for use in older children, PRP-D is at least as safe and significantly more immunogenic.

Avascular Necrosis of the Hip: A Complication Following Treatment of Congenital Dysplasia of the Hip:

Eaarly identification and management of congenital dysplasia of the hip are essential to optimizing mobility of the hip. Greater awareness, widespread use of ultrasound assessment, and an expanding array of therapies have been successful in enhancing normalcy. Despite these advances, avascular necrosis remains the most serious complication following treatment for hip dysplasia; a childs physician must be aware of this sequela. Avascular necrosis has been reported with almost every form of hip splintage, partially reflecting the severity of the dysplasia, duration of splintage, and delays in making the initial

1134 STUDIES OF SAFETY AND IMMUNOGENICITY OF HAEMOPHILUS INFLUENZAE TYPE B POLYSACCHARIDE DIPHTHERIA TOXOID CONJUGATE VACCINE (PRP-D) IN CHILDREN 7–14 MONTHS OF AGE

In a multicenter study, 502 normal infants ages 7-14 months were randomized to receive either 2 doses of PRP-D intramuscularly containing 20 ug PRP (80%) or placebo (20%) 6-10 weeks apart. Serum samples were obtained from 25% prior to each injection and 1 month post second dose and tested by Farr-type radioimmunoassay for anti-PRP antibody. Reaction data are available from 400 subjects. The incidence of local erythema at the injection site was 2.4% and irritability 3% in both groups. Two PRP-D recipients had temperatures greater than 1022(R). Among 120 children tested for antibody, 99% of PRP-D recipients demonstrated a two fold or greater rise in anti-PRP compared with 5% of placebo recipients. Median anti-PRP levels in the two groups were 7.0 and 0.012 ug/ml respectively. After 2 doses of PRP-D, 95% had ≥ 0.15 ug/ml antibody protein/ml and 90% had > 1 ug/ml. This study confirms prior observations in 9-14 month olds that PRP-D can induce primary and booster antibody responses in infants over 7 months compatible with protection against H. influenzae b disease.

Immunization Status: A Parameter of Patient Compliance

From the Department of Pediatrics, University of Colorado Medical Center and the Department of Health and Hospitals, City and County of Denver, Denver, Colorado. Correspondence to: Roger M. Barkin, M.D., Department of Pediatrics, University of Colorado Medical Center, 4200 East Ninth Avenue, Denver, CO 80262. 0 NE OF THE HALLMARKS of pediatric practice today is the provision of preventive health services. Viewed pragmatically, the efficacy of such care reflects the response of parents to the medical care system. Barriers decrease the effectiveness of this relationship; poor compliance is one of these ‘

350 DIPHTHERIA-PERTUSSIS-TETANUS VACCINE: REACTOGENICITY OF COMMERCIAL PRODUCTS

Widespread use of diphtheria-pertussis-tetanus (DPT) vaccine necessitates evaluation of reaction rates. Parents from 4 practices were surveyed to ascertain reactions of children to DPT vaccine in the 48 hours after immunization. Vaccines were administered according to current recommendations. Responses were scored in 3 categories (points in parentheses): Temperature: 100-102°F(1) and > 102°F(3); Behavior: irritability(1), crying (2), and screaming(3); Local Reactions: redness(1), swelling(1), and tenderness(1). Other reactions were given one point. A score was determined for each patient, points being given for the most severe temperature and/or behavioral reaction, and an additive score for each of the local reactions observed for a maximum of 10. 621 (82.3%) patients returned questionnaires. The average score was 3.54 ± 2.04.Over 50% experienced temperatures of at least 100°F and 80% noted behavioral changes. 75.4% had local reactions. No encephalitis, seizures, or hospitalizations were reported. Reactogenicity was similar for the 5 immunizations of the recommended series. These reaction rates underline the need to further evaluate present vaccine products.