Comparison of diphtheria-tetanus-two component acellular pertussis vaccines in United States and Japanese infants at 2, 4, and 6 months of age.

OBJECTIVE: We compared the diphtheria and tetanus toxoids and bicomponent acellular pertussis vaccine (DTaP) responses in Japanese and United States infants. DESIGN: This was a double-blind, comparative study. SETTING: Private pediatric practices in Japan and the U.S. participated. SUBJECTS: One hundred eighty-nine healthy 2-month old infants were tested. INTERVENTIONS: Infants were immunized at 2, 4, and 6 months of age. The Japanese formulation (DTaP-J) contained 20 micrograms of pertussis toxin (PT) and 20 micrograms of filamentous hemagglutinin (FHA); the U.S. formulation (DTaP-US) contained 23.4 micrograms of each antigen. Parents used a standard form to record average adverse experiences. Serum was obtained before the first immunization, 2 months after the second immunization, and 1 month after the third immunization. MEASUREMENTS: Differences in DTaP-J and DTaP-US were evaluated in Japanese infants immunized subcutaneously (s.c.). Differences due to ethnicity and to route of administration were compared in U.S. infants immunized with DTaP-US s.c. or intramuscularly (i.m.). An indirect enzyme-linked immunosorbent assay was used to determine immunoglobulin G antibody responses to PT, FHA, and tetanus toxoid. Neutralizing antibody to PT was measured by a Chinese hamster ovary call assay. Diphtheria antitoxin was assayed by serum neutralization on VERO cells. RESULTS: Statistical differences (P < .05) in adverse events included less fatigue after immunization with DTaP-US compared with DTaP-J. Erythema of more than 2.5 cm was more frequent, but erythema less than 2.5 cm was less frequent in Japanese infants compared with U.S. infants. Fewer Japanese infants were febrile ( > 38 degrees C), tired, or irritable. Subcutaneous immunization resulted in a greater frequency of erythema and induration. The DTaP-US resulted in an equivalent response to PT and a greater response to FHA. More Japanese infants demonstrated at least a fourfold response over preimmunization antibody values to FHA. In U.S. infants, antibody responses to the contained pertussis antigens were equivalent after i.m. and s.c. administration. Compared with Japanese infants receiving DTaP-J s.c., U.S. infants receiving DTaP-US i.m. had equivalent responses to PT and a greater response to FHA. CONCLUSIONS: United States infants receiving an i.m. injection of a U.S. -produced bicomponent DTaP vaccine produced antibody responses to the contained pertussis antigens at least equal to those of Japanese infants receiving a similar bicomponent DTaP vaccine shown to be effective in older Japanese children.

Ten-year survey of the intellectual deficits in children with acute lymphoblastic leukemia receiving chemoimmunotherapy.

Effects of chemoimmunotherapy, including cranial irradiation for central nervous system (CNS)-directed therapy, on children with acute lymphoblastic leukemia (ALL) were investigated. Fifty-five children with ALL in continuous complete remission (> 5 yr) and without evidence of current or past CNS diseases were evaluated in this retrospective study. Using standard measures of intelligence (IQ), we repeatedly (1-4 times/person; mean 2.1 times) evaluated IQ in the cohort of patients for the mean follow-up time of 9.7 yr, ranging from 5.4 to 15.8 yr. Fifty-five patients received the total number of 118 IQ testings and 40 patients received them more than twice. Patients were examined periodically at intervals of 1.4 to 10.0 yr (mean 4.8 yr) following diagnosis. Most of the published studies dealt with single IQ testing, and long-term follow-ups were not enough to assess the consequent IQ change. This report confirms and extends the previous findings: decreased IQ was related to age at diagnosis and irradiation (< 5 yr of age at diagnosis), irradiation-examination interval, and female sex. Further long-term follow-up study will be needed in these groups, since their IQs are still on the decline even after 10 yr of diagnosis.

Immunogenicity and reactogenicity of Takeda acellular pertussis-component diphtheria-tetanus-pertussis vaccine in 2- and 3-month-old children in Japan.

OBJECTIVE: To compare the reactogenicity and immune response to the Takeda acellular pertussis-component diphtheria-tetanus-pertussis (APDT) vaccine in children when immunization commenced at 2 months (group A) vs 3 months (group B) of age. DESIGN: Longitudinal, nonblinded, comparative study. SETTING: Pediatric well-child clinics. PARTICIPANTS: Healthy 50- to 98-day-old infants. RESULTS: Good antibody responses to lymphocytosis-promoting factor, filamentous hemagglutinin, agglutinogens, and pertactin occurred in both age groups after both the third and fourth vaccine doses. Both young age and transplacentally acquired maternal antibody independently and together have a suppressive effect on the response to the four antigens in this APDT vaccine. However, these effects appear to be minor. Vaccine reactions were mild; group A children had slightly but not significantly higher rates than group B children. CONCLUSION: The present US diphtheria and tetanus toxoids and pertussis vaccine immunization schedule should also be satisfactory with this acellular pertussis component vaccine.

A comparative trial of the reactogenicity and immunogenicity of Takeda acellular pertussis vaccine combined with tetanus and diphtheria toxoids. Outcome in 3- to 8-month-old infants, 9- to 23-month-old infants and children, and 24- to 30-month-old children.

The reactogenicity and immunogenicity of the Takeda acellular pertussis vaccine combined with tetanus and diphtheria toxoids were compared in 139 infants aged 3 to 8 months, 60 infants and children aged 9 to 23 months, and 99 children aged 24 to 30 months. Good antibody responses to pertussis toxin (PT), filamentous hemagglutinin (FHA), and agglutinogens occurred in all age groups after both the third and fourth doses. After the fourth (booster) dose, the mean antibody values in initially seronegative infants vaccinated at 3 to 8 months of age were as follows: anti-PT, 67.8 enzyme-linked immunosorbent assay units (EU) per milliliter; anti-FHA, 149.5 EU/mL; the agglutinin titer was 125.6. The values in initially seronegative children vaccinated at 24 to 30 months of age were as follows: anti-PT, 92.9 EU/mL; anti-FHA, 251.7 EU/mL; the agglutinin titer was 275.8. Reactions following immunization were minimal. Except for drowsiness after the first dose in infants, there were no clinically significant differences in reactions between infants and older children. The findings in this study coupled with the recent demonstration of efficacy of this vaccine in 2-year-old children supports the recent Japanese recommendation to lower the age of immunization with acellular pertussis vaccine combined with tetanus and diphtheria toxoids to 3 months.

Effect of serum treatment on pertussis antibody determination by ELISA.

Determination of anti-PT and anti-FHA antibodies by ELISA and neutralization titer by CHO-cell method were performed with inactivated and uninactivated human sera. The findings were as follows: in inactivated sera, higher anti-PT ELISA antibody titers were shown compared with the titers determined with corresponding inactivated sera, especially in sera having low ELISA antibody titers; however, anti-FHA ELISA antibody titers remained identical, with the uninactivated or inactivated sera. CHO-cell neutralization titer remained identical and stable between the uninactivated and inactivated sea. CHO-cell neutralization titers correlated with anti-PT ELISA antibody titers in sera without inactivation. Anti-PT ELISA antibody titers in inactivated sera, however, did not correlate with the corresponding CHO-cell neutralization titers. These results suggest the possible existence of (a) substance(s) with affinity to PT which enhance(s) the ELISA reaction when sera are inactivated. Therefore, the inactivation of sera is not favorable for anti-PT determination by ELISA.

Clinical use of Biken acellular DPT in two-month old infants.

We have examined the antibody titer and side effects in two-month-old infants (1.5-2.5) who received vaccinations of acellular DPT Combined Vaccine Adsorbed "Biken" Lots 22 and 23. We observed high-antibody titers far in excess of prevention levels. No particular increase in side effects was observed in the two-month-old infants, except a normal increase in once-only side effects. The results suggest that this vaccine can protect infants under one year of age, who are especially liable to be affected by this illness.

Overview of currently available Japanese acellular pertussis vaccines and future problems.

Acellular pertussis diphtheria, tetanus vaccine (APDT) was licensed in 1981 in Japan. This vaccine contains pertussis toxin (PT), filamentous hemagglutinin (FHA) and agglutinogen (AGG) as the main protective antigens. The new APDT vaccine produced by each company differs slightly in composition. There are two representative types of vaccine. One vaccine (B type) contains PT and FHA in a ratio of 1 to 1 and the other one (T type) contains PT and FHA in a ratio of 4 to 1 or 9 to 1 and also contains different amounts of AGG. We have been comparing the effectiveness of these two types of vaccine. The adverse reactions of APDT were local reactions such as redness and swelling, with a few febrile cases. No central nervous system adverse reactions were observed. The antibody protective level of this vaccine is also being investigated. After we changed from conventional vaccine to APDT, the frequency of serious adverse reactions was reduced and the number of pertussis infections also gradually decreased. This vaccine should be used for the children world-wide.

Japanese clinical trials with Takeda acellular pertussis vaccine.

Japanese clinical trials with Takeda acellular pertussis vaccine revealed that infants 3 to 8 months of age reacted sufficiently to the vaccine: anti-PT ant-FHA levels after vaccination were as high as those observed with 2 year old children. No substantial difference in general reactions was noted between infants and 2 year old children. Less local reactions were noted in infants.