Search

The new acellular pertussis vaccine combined with diphtheria and tetanus toxoids (DTaP) appears to confer comparable immunity and result in fewer adverse side effects than the traditional whole-cell pertussis combination (DTwP). A total of 1,293 children receiving their fourth dose of vaccine were given either a US-licensed DTwP or one of 12 different DTaP preparations. Some of the children had had DTwP for their first boosters, while others had always been given DTaP. In general, the DTaP vaccine resulted in fewer side effects and similar antibody responses, regardless of the previous vaccine type., ABSTRACT. Objective. To compare the safety and immunogenicity of 12 different acellular pertussis vaccines combined with diphtheria and tetanus toxoids (DTaP) with one licensed diphtheria, tetanus, and whole-cell pertussis vaccine (DTwP) as a fourth-dose booster in children who had previously received DTaP or DTwP primary vaccinations. Methods. Healthy 15- to 20-month-old children were enrolled at six National Institutes of Health Vaccine Treatment and Evaluation Units. All had been randomly assigned to receive three primary doses of DTaP or DTwP at 2, 4, and 6 months of age as part of an earlier National Institutes of Health multicenter trial of DTaP vaccines in the same Vaccine Treatment and Evaluation Units. Parents recorded the occurrence and magnitude of fever; irritability; and injection site redness, swelling, and pain for 3 days after vaccination. Sera obtained before and 1 month after the booster vaccination were analyzed for antibody to pertussis toxin (PT), filamentous hemagglutinin (FHA), fimbriae (FIM), and pertactin (PRN). Diphtheria and tetanus toxoid as well as PT neutralizing (Chinese hamster ovary cell) and whole-cell agglutinating antibodies were measured on a subset of sera. Results. A total of 1293 children contributed fourth-dose reaction data. Reactions were less frequent after DTaP than after DTwP. For children vaccinated with a fourth dose of DTaP, which was the same DTaP as received in the primary series, fever and injection site redness, swelling, and pain increased in prevalence compared with the third dose in the primary series. For children receiving DTaP as a fourth dose, injection site redness and swelling occurred more frequently in DTaP-primed than in DTwP-primed children. Variation in the occurrence of reactions among DTaP vaccines was observed. A total of 1160 paired pre- and postvaccination sera were available for analysis. Serum antibody concentrations before boosting were lower than those obtained 1 month after the primary immunization. After the fourth dose, significant increases in antibodies directed against the included antigens were observed for all vaccines; postbooster vaccination antibody titers differed significantly among the DTaP vaccines. For children primed and boosted with the same DTaP, antibody levels were not directly related to the quantity of antigen included for PT, FHA, and FIM; for PRN, there was a closer relationship. Some DTaP vaccines given as fourth-dose boosters elicited antibody to PRN or FIM in some vaccinees, although the DTaP vaccines were not reported to contain these antigens; these responses were observed more frequently in DTwP-primed children. Agglutinin antibody rises were observed in all groups immunized with four doses of a DTaP vaccine containing FHA or PRN, regardless of whether the vaccine included FIM. Diphtheria and tetanus antibody levels exceeded the presumed protective concentration (0.1 IU/mL for diphtheria and 0.01 IU/mL for tetanus) after the fourth dose for all vaccinees. Conclusion. Although differences were observed in reaction rates among the DTaP vaccines given as a fourth dose, the DTaP vaccines were, in general, associated with fewer adverse events than a US-licensed DTwP. For DTaP vaccines, fever; irritability; and injection site pain, redness, and swelling occurred more frequently after the fourth dose than after the third dose of the same vaccine in the primary series. No DTaP was consistently most or least reactogenic or immunogenic. Although serologic correlates of pertussis immunity are not defined, it is clear that most DTaP vaccines can stimulate comparable or higher serum antibody responses than DTwP for those antigens contained in the vaccine., Pediatrics 1997;100:772-788; acellular, adverse reactions, antibody, diphtheria-tetanus-pertussis vaccine, pertussis vaccine, whole cell, whooping cough. ABBREVIATIONS. DTaP, diphtheria and tetanus toxoids combined with acellular pertussis vaccine; DTwP, diphtheria and tetanus toxoids [...]

The effectiveness of vaccination against pertussis appears to vary according to race. Among a population of 2,143 infants participating in a trial of the effectiveness of 13 new types of pertussis vaccine versus two standard types, 5% were black. Data on circulating antibody levels both before and after immunization were available for 1,768 infants. Black infants had similar anti-pertussis antibody levels before immunization, but consistently had about twice the level of circulating antibodies after immunization compared with white infants. These results held after statistical adjustment for the potentially confounding factors of sex, level of parental education, socioeconomic status, clinic site, and antibody level before immunization. These results must be interpreted with caution because racial identification is both complex and subjective., Objective. To determine whether gender, race (black or white), or level of parental education influenced serologic responses or reporting of clinical reactions after immunization with acellular (DTaP) or whole-cell (DTP) pertussis vaccine with diphtheria and tetanus toxoids combined. Methods. Healthy infants were prospectively randomized to receive one of 13 DTaP, Lederle DTP, or another DTP. Parents recorded the occurrence of adverse reactions for 2 weeks after each inoculation. Sera obtained before the first immunization and I month after the third immunization were analyzed for antibody to pertussis toxin, filamentous hemagglutinin, fimbriae, and pertactin (PRN). Chinese hamster ovary cell pertussis toxin neutralization assays were performed, and levels of agglutinating antibodies determined. Results. Prevaccination antibody levels did not differ by race, gender, or parental education. Postimmunization geometric mean titers (GMTs) were strongly and consistently associated with race. For both DTaP and DTP and for every included antigen, postimmunization GMTs were about twice as high for black as for white infants. Among DTAP recipients, these differences were significant for pertussis toxin, Chinese hamster ovary cell pertussis toxin neutralization assay, filamentous hemagglutinin, PRN, and agglutinins, among the much smaller sample of WCL recipients, the differences achieved or approached statistical significance for agglutinins, PRN, and fimbriae. These findings were confirmed by regression analyses that controlled for gender, parental education, study site, and preimmunization antibody level. Reported reactions were not correlated with parental education level and showed no material correlation with gender. Black infants were reported to have had more pain than white infants after receiving WCL and DTaP and were reported to be more fussy after receiving WCL. Conclusions. The consistently higher postimmunization GMTs among black infants seems to be a real finding for which we have no explanation; the infants did not significantly differ by race in vaccine assignment, preimmunization antibody levels, age at immunization, or interval from immunization to phlebotomy. These observations should be confirmed and further evaluated in future pertussis vaccine trials. Reported differences by race in pain and fussiness after receiving WCL might reflect chance, differences by race in the occurrence of reactions, or differences by race in the reporting of reactions. Pediatrics 1995;96:584-587; acellular, antibody, diphtheria-tetanus-pertussis, vaccine, whole-cell, whooping cough., ABBREVIATIONS. DTP, diphtheria and tetanus toxoids combined with whole-cell pertussis vaccine; DTaP, diphtheria and tetanus toxoids combined with acellular pertussis vaccine; PT, pertussis toxin; FHA, filamentous hemagglutinin; PRN, pertactin; FIM, [...]

The new acellular pertussis vaccines appear to be more effective at inducing an immune reaction than the conventional whole cell vaccine. A group of 1,942 infants were randomly assigned to receive their regular series of three diphtheria-pertussis-tetanus immunizations with one of 13 varieties of acellular pertussis vaccine or the conventional whole cell vaccine. The new vaccines used one or more of four protein components of Bordetella pertussis, the bacterium that causes whooping cough, to stimulate antibody formation. All vaccines stimulated antibodies against the proteins contained in the vaccine. In most cases, antibody levels exceeded amounts formed in response to the whole-cell vaccine. All vaccines produced sufficient antibody levels to diphtheria and tetanus as well. Antibody levels against pertussis components differed among the 13 acellular vaccines, but whether these differences are important is unknown., Objective. To compare the immunogenicity of a licensed conventional whole-cell (WCL) and 13 diphtheria-tetanus-acellular pertussis (DTaP) vaccines that differed in source, method of manufacture, and included antigens; all vaccines included diphtheria and tetanus toxoids. Methods. Healthy infants were enrolled through six university-based vaccine and treatment evaluation units and were randomized to receive one of the study vaccines at 2, 4, and 6 months of age. Sera were obtained before the first immunization and 1 month after the third immunization and were analyzed for antibody to pertussis toxin (PT), filamentous hemagglutinin, fimbriae, pertactin, and diphtheria and tetanus toxins. Chinese hamster ovary cell toxin neutralization assays were performed, and levels of agglutinating antibodies were determined. Results. Of 2342 infants enrolled, 1942 contributed usable preimmunization and postimmunization serum specimens. Each vaccine produced significant increases in antibodies directed against the included antigens; postimmunization antibody titers differed significantly among the DTaP vaccines. For each evaluated antigen, the majority of DTaP vaccines produced antibody responses that equaled or exceeded those produced by WCL. For some antigens (eg, PT), mean antibody levels by vaccine correlated poorly with the quantity of antigen included in each vaccine; for others (eg, fimbriae), there was a close correlation. Conclusion. Although serologic correlates of pertussis immunity are not defined, it is clear that DTaP vaccines can stimulate immune responses that exceed those of licensed whole-cell vaccine with respect to the measured antibodies. Particularly for PT, immunogenicity seems to depend on factors in addition to antigen concentration, possibly including antigen derivation and formulation. No DTaP was most or least immunogenic with respect to all included antigens. Pediatrics 1905,96:548-557; acellular, antibody, diphtheria-tetanus-pertussis, pertussis, vaccine, whole-cell, whooping cough., ABBREVIATIONS. DTP, diphtheria and tetanus toxoids combined with whole-cell pertussis vaccine; PT, pertussis toxin/toxoid; FHA, filamentous hemagglutinin; FIM, fimbrial protein; PRN, pertactin; DTaP, diphtheria and tetanus toxoids combined with acellular [...]

Only certain symptoms and severities of common adverse effects may need to be monitored in order to discriminate among pertussis vaccines. Parents of 2,342 infants monitored fever, redness, swelling, and pain at the injection site, fussiness, drowsiness, vomiting, and acetaminophen use after immunization as part of a trial of 13 new pertussis vaccines versus two standard types. The following served as sufficient means to discriminate clinically significant differences in reactions to the vaccines: fever greater than 100 degrees F, moderate or severe fussiness, redness or swelling at the injection site, and moderate or severe pain at the injection site. In addition, it may be useful to monitor acetaminophen use, and parents should be asked to report unusual or unexplained symptoms during the two- to four-week interval after immunization and again a year after immunization., ABSTRACT. Objective. To facilitate future vaccine reaction data collection and analysis, we sought to determine the minimum data set required to describe accurately and to compare common reactions after the administration of acellular (DTaP) or whole-cell (DTP) pertussis vaccine with diphtheria and tetanus toxoids combined. Methods. Thirteen DTaP and 2 DTP vaccines were studied in a multicenter trial involving 2342 infants who received a primary series of vaccinations at 2, 4, and 6 months of age. Temperature, fussiness, redness, swelling and pain at the injection site, antipyretic use, drowsiness, loss of appetite, and vomiting were evaluated. Reactions were assessed at 3 hours and (if not immunized in the evening) 6 hours after immunization, at bedtime each evening for 7 evenings, and on the 14th evening after immunization. Results. Two reaction assessment approaches were compared: (1) analysis of all reactions, regardless of the degree of severity; and (2) a condensation of the data to five key reactions (fever >100[degrees]F, moderate or more fussiness, any local redness, any local swelling, and moderate or more local pain). We found that the onset of reactions was infrequent beyond the second evening, and that collection and analysis of reaction data beyond that time did not further discriminate among the vaccines. Information regarding antipyretic use, loss of appetite, drowsiness, or vomiting did not assist in differentiating among these vaccines. Conclusion. Monitoring the occurrence of fever greater than 100[degrees]F, moderate or severe fussiness, injection site redness or swelling; and moderate or severe injection site pain occurring through the second evening after immunization will provide the minimum data set needed to discriminate among DTaP and DTP vaccines with respect to the common adverse reactions. Pediatrics 1995,96:588-592; acellular, adverse reactions, diphtheria-tetanus-pertussis vaccine, pertussis vaccine, whole-cell, whooping cough., ABBREVIATIONS. DTP, diphtheria and tetanus toxoids combined with whole-cell pertussis vaccine; DTaP, diphtheria and tetanus toxoids combined with cellular vaccine. We conducted a multicenter, comparative evaluation of 13 acellular (DTaP) [...]

Maternal anti-pertussis antibodies transferred to the infant before birth do not appear to interfere with immunization response among infants given an acellular pertussis vaccine. Acellular vaccines are a new type of whooping cough vaccine that induce immunity to certain protein components of the pertussis-causing bacterium instead of using whole, killed bacteria. Researchers analyzed blood antibody levels in 1,906 infants before and after their diphtheria-pertussis-tetanus immunization with either an acellular vaccine or whole-cell vaccine. Higher levels of circulating maternal antibody in the infant prior to immunization were associated with lower levels of antibody after immunization, but the effect was strongest only among recipients of whole-cell vaccines. This suggests that adult women could be immunized against pertussis with an acellular vaccine without interfering with the effectiveness of immunization in subsequent children provided they also received an acellular vaccine., Objective. To evaluate the effect of maternally derived antibody on the immunogenicity and reactogenicity of acellular (DTaP) or whole-cell (DTP) pertussis vaccine with diphtheria and tetanus toxoids combined. Methods. A total of 2342 infants were randomized to receive one of 13 DTaP or 2 DTP vaccines at 2, 4, and 6 months of age. The correlation between preimmunization and postimmunization antibody after three doses of vaccine and the relation between preimmunization antibody and adverse reactions after the first immunization were modeled by linear regression. Results. After DTP but not DTaP, higher levels of preexisting antibody were associated with substantial (28% to 56%) reductions in the subsequent antibody response to pertussis toxin (PT). For other pertussis antibodies, modest inverse correlations were seen between preexisting antibody concentrations and most postimmunization antibody responses (resulting in 8% to 18% reductions in postimmunization antibody) for both DTP and DTaP. There was no consistent association in any DTP or DTaP group between adverse reactions and preimmunization antibody levels. Conclusion. The PT antibody response to DTaP, unlike DTP, is not adversely affected by preexisting antibody to PT. Inhibitory effects with respect to other antibodies, seen with both DTP and DTaP, were relatively modest. Our data suggest that the use of acellular pertussis vaccines in adults, which could confer higher levels of antibody in women before pregnancy, would be unlikely to adversely affect pertussis antibody responses after DTaP among infants born to mothers with high antibody levels. Pediatrics 1995;96:580-584; acellular, antibody, diphtheria-tetanus-pertussis, maternal, pertussis, whole-cell, vaccine, whooping cough., ABBREVIATIONS. DTP, diphtheria and tetanus toxoids combined with whole-cell pertussis vaccine; DTaP, diphtheria and tetanus toxoids combined with acellular pertussis vaccine; PT, pertussis toxin; FHA, filamentous hemagglutinin; FIM, fimbrial protein; [...]

Giving a vaccination against Haemophilus influenzae Type b (Hib) at the same time as a new type of pertussis vaccine does not appear to interfere with the effectiveness of the pertussis vaccine or increase its side effects. Partway through a large, multicenter trial comparing 13 new types of pertussis vaccine with two standard types, the Hib vaccine was introduced. Therefore, some children received the Hib vaccine at the same visit as one of their diphtheria-pertussis-tetanus (DPT) immunizations. This allowed a comparison of effects between children receiving Hib and children who did not. The Hib vaccine had no consistent effect on antibody levels to protein components of the pertussis-causing bacterium., Objective. To evaluate the effect of simultaneous Haemophilus influenzae type b conjugate (Hib) vaccination on the safety and immunogenicity of selected acellular (DTaP) and whole-cell (DTP) pertussis vaccines with diphtheria and tetanus toxoids combined. Methods. Enrollment of infants into a large multicenter study of the safety and immunogenicity of 13 DTaP and 2 DTP vaccines was partially completed when the first Hib vaccine, HbOC (Haemophilus bioligosaccharide conjugate vaccine), was licensed for use in infants. Thereafter, at each immunization most infants received HbOC simultaneously with DTaP (or DTP), administered in opposite thighs. Postvaccination geometric mean titers or concentrations (GMTs) of pertussis antibodies as measured by six different assays were compared pairwise among groups of infants receiving 0, 1, 2, or 3 simultaneous HbOC immunizations. The incidence of reactions was compared between infants who received only DTaP or DTP and those who received HbOC simultaneously. Results. Comparison of postvaccination GMTs was possible among groups of infants receiving different numbers of simultaneous immunizations for 10 of the 13 DTaP and both DTP vaccines. Increased HbOC exposure had no consistent dose-response effect on antibody titers for DTaP or DTP vaccines in any assay. Significant differences between groups in postvaccination GMTs were observed with 4 DTaP vaccines in 1 to 2 assays each; the GMTs were higher with increasing HbOC exposure for 2 DTaP vaccines and lower for 2 others. There was no significant increase in reactions with simultaneous HbOC and DTaP immunization. Conclusions. Based on these retrospective analyses, there did not seem to be an interference in pertussis immunogenicity or alteration in reactogenicity associated with the simultaneous administration of HbOC and DTaP. These findings are encouraging with respect to the development of DTaP-Hib combination vaccines. Pediatrics 1995;96:576-579; acellular, antibody, diphtheria-tetanus-pertussis, Haemophilus influenzae, pertussis, vaccine, whole-cell, whooping cough., ABBREVIATIONS. DTaP, diphtheria and tetanus toxoids combined with acellular pertussis vaccine; DTP, diphtheria and tetanus toxoids combined with whole-cell pertussis vaccine; Hib, Haemophilus influenzae type b; GMT, geometric mean titer [...]

The new acellular pertussis vaccines do not appear to produce as many side effects as the conventional whole-cell vaccine. Acellular vaccines induce immunity to protein components of Bordetella pertussis, the bacterium that causes whooping cough. A group of 2,189 infants were randomly assigned to receive their regular series of three diphtheria-pertussis-tetanus immunizations with one of 13 varieties of acellular pertussis vaccine or the conventional whole cell vaccine. Parents kept track of the infant's temperature and other adverse symptoms after each vaccination. Fever and redness, swelling, or pain around the injection site were all less common and less severe after vaccination with the acellular vaccines compared with the whole-cell vaccine. The incidence of vomiting was similar. More serious adverse reactions were rarer as well. Overall, 2.5%. of the infants receiving the conventional vaccine were withdrawn from the trial mostly for prolonged, inconsolable, or high-pitched crying compared with 0.8% of infants receiving an acellular vaccine., Objective. To compare the reactogenicity of a licensed conventional whole-cell (WCL) and 13 acellular pertussis vaccines that differed in the source, manufacture, and quantity of included antigens; all vaccines included diphtheria and tetanus toxoids. Methods. Healthy infants were enrolled through six university-based vaccine and treatment evaluation units and were randomized to receive one of the study vaccines at 2, 4, and 6 months of age. Parents recorded the occurrence of fever, redness, swelling, pain, fussiness, drowsiness, anorexia, and use of antipyretics for 2 weeks after each inoculation; nurses interviewed parents on the third day and at each succeeding visit; long-term follow-up information was collected from parents and medical records 1 year after the third immunization. Results. Of 2200 vaccinated infants, 2189 contributed reaction data after 6375 vaccinations. For every acellular vaccine, every monitored reaction except vomiting occurred at a significantly lower frequency and severity than was seen with WCL. The groups receiving acellular pertussis vaccines differed significantly with respect to redness, swelling, pain, and vomiting, but not with respect to fussiness, antipyretic use, drowsiness, or anorexia. Conclusion. Although there were differences among the acellular vaccines, none was consistently the most or least reactogenic; all were associated with substantially fewer and less severe adverse reactions than a standard commercial whole-cell vaccine. Selection of acellular vaccines for further development and for introduction into efficacy trials can give priority to assessments of immunogenicity and purity, with comparative reactogenicity a secondary consideration. Pediatrics 1995;96:557-566; acellular, adverse reactions, diphtheria-tetanus-pertussis vaccine, pertussis vaccine, whole cell, whooping cough., ABBREVIATIONS. DTP, diphtheria and tetanus toxoids combined with whole-cell pertussis vaccine; DTaP, diphtheria and tetanus toxoids combined with acellular pertussis vaccine; SIDS, sudden infant death syndrome. For the abbreviations used [...]

Antibody response and frequency of side effects may vary between different brands of whole-cell pertussis vaccines. Whole-cell pertussis vaccines are the vaccines in current use to immunize against whooping cough. Ninety-four infants received their diphtheria-pertussis-tetanus immunization series at two, four, and six months with pertussis vaccine supplied by one manufacturer and 309 received vaccine from another manufacturer. One month after the series was completed, blood samples were tested for antigen response to four protein components of the pertussis-causing bacterium. The two vaccines varied in the immune responses they stimulated to these proteins. Infants receiving one type of vaccine were also less likely to have fevers of 101 degrees or more, pain or swelling at the injection site, or inconsolable crying., Objective. To compare prospectively the reactogenicity and immunogenicity of two licensed whole-cell pertussis vaccines. Methods. We conducted a prospective, randomized, double-blinded assessment of two licensed whole-cell pertussis vaccines with diphtheria and tetanus toxoids that were included in a multicenter trial evaluating 13 acellular pertussis vaccines. Infants were immunized at 2, 4, and 6 months of age with a single lot of Lederle (309 infants) or Massachusetts Public Health Biologic Laboratories (MPHBL; 94 infants) vaccine. Results. The group receiving the Lederle vaccine demonstrated significantly higher antibody titers to pertussis toxin by enzyme-linked immunosorbent assay (ELISA) and by the Chinese hamster ovary cell pertussis toxin neutralization assay, and to fimbrial antigens by ELISA, as well as higher mean agglutinin titers. In contrast, the group receiving the MPHBL vaccine demonstrated higher ELISA antibody levels to filamentous hemagglutinin and pertactin. Similar differences were observed in the proportions of vaccinees seroconverting to these antigens. Rates of systemic and local reactions were relatively low for both vaccines. Although the Lederle product had substantially lower reactogenicity in this study than previously reported for that vaccine, the MPHBL vaccine was significantly less reactogenic in nearly all clinical categories. Conclusion. The two whole-cell vaccines demonstrated statistically significant differences in postimmunization antibody levels to all six evaluated pertussis antigens. Whether these statistically significant differences in antibody levels have clinical relevance is not clear. Rates of nearly all local and systemic reactions were significantly lower among the MPHBL group than the Lederle group. Licensed whole-cell diphtheria-tetanus-pertussis vaccines produced by different manufacturers cannot be assumed to be similar in reactogenicity or immunogenicity. Pediatrics 1995;96:567-570; pertussis vaccine, infants, immune response, antibody, controlled trial., ABBREVIATIONS. DTP, diphtheria and tetanus toxoids combined with whole-cell pertussis vaccine; MPHBL, Massachusetts Public Health Biologic Laboratories; ELISA, enzyme-linked immunosorbent assay; PT, pertussis toxin; FHA, filamentous hemagglutinin; PRN, pertactin; FIM, [...]

Infants vaccinated with a combination of two conjugated Haemophilus influenzae type b vaccines appear to be more effectively protected against the disease than when the vaccines are used separately. A total of 242 two-month-old infants were randomly assigned to one of five vaccination schedules. Infants in two of the groups received either polysaccharide polyribosyl-ribitol phosphate conjugated to the meningococcal outer membrane protein (PRP-OMP) or a vaccine derived from Corynebacterium diphtheriae (HbOC). Infants in a third group received PRP-OMP on an alternative schedule while infants in the fourth and fifth groups received a combination of the two vaccines. At the end of the vaccination series blood tests were done to determine the infants' immunity to the disease. Infants who received a combination of PRP-OMP and HbOC had significantly higher markers of disease immunity than the infants who received only one type of vaccine. Side effects were minimal and were similar between the groups., Objective. - To evaluate the safety and immunogenicity of two Haemophilus influenzae type b (Hib) conjugate vaccines when administered in serial combination. These vaccines consisted of Hib capsular polysaccharide polyribosyl-ribitol phosphate (PRP) conjugated to the meningococcal outer membrane protein (OMP) complex (PRP-OMP) and H influenzae oligosaccharide conjugated to a mutant toxin (CRM 197) isolated from Corynebacterium diphtheriae (HbOC). Design. - Randomized, double-blind, clinical trial evaluating five Hib vaccination regimens. Setting. - Vaccine Treatment and Evaluation Units and affiliated private pediatric practices at Saint Louis (Mo) University, Vanderbilt University, Nashville, Tenn, and Baylor College of Medicine, Houston, Tex. Patients. - A total of 497 healthy 2-month-old infants scheduled to receive routine immunization. Intervention. - Participants received either PRP-OMP or HbOC given as recommended by the manufacturer, PRP-OMP at 2 and 6 months, HbOC at 2 months, then PRP-OMP at 4 and 6 months, or PRP-OMP at 2 months and then HBOC at 4 and 6 months. Unconjugated PRP was given at 15 months to evaluate priming. Results. - Geometric mean antibody concentrations differed significantly among the groups following the second and third immunizations of the primary series and following booster immunization with unconjugated PRP. On each occasion, the groups receiving serial combinations of PRP-OMP and HbOC achieved mean antibody concentrations that equalled or exceeded those of the groups receiving a single product. Adverse reactions did not vary by group. Conclusions. - The studied sequential combinations of Hib vaccines were safe and at least as immunogenic as either vaccine alone.

Acellular (AC) pertussis vaccines may be as effective as whole-cell (WC) pertussis vaccines. Although proven effective in preventing disease in infants and children, WC pertussis vaccines are strongly associated with adverse reactions. To evaluate the efficacy and safety of nine AC pertussis vaccines, researchers studied 240 children between the ages of 16 and 21 months and four and six years. Of these children, 182 received one of the AC vaccines and 58 received WC vaccines. No serious adverse reactions were recorded for the entire group. Children in the AC group reported lower reaction rates than the WC group in the first 48 hours after injection. The AC group reported significantly less fever, pain, swelling, redness, limpness or acetaminophen use in the 48-hour post-immunization period. The AC vaccines also produced comparable or better antibody responses than the WC vaccines. More research is necessary to evaluate the relationship of antibody levels and protective efficacy in AC vaccines., ABSSTRACT. Objective. To compare the safety and immunogenicity of a variety of acellular (AC) and whole-cell (WC) pertussis vaccines combined with diphtheria and tetanus toxoids. Methods. Standard enrollment and reaction forms were used at five sites, and serologic evaluation was performed at a single site. Nine AC (Massachusetts Public Health Laboratories, Biocine Sclavo recombinant pertusis toxoid [PT], Connaught/BIKEN, Lederle three-component, Biocine Sclavo recombinant three-component SmithKline Beecham three-component, Porton three-component, Takeda-Wyeth, and Connaught multicomponent), and three WC (Connaught Laboratories, Lederle Laboratories, and Massachusetts Public Health Laboratories were studied. All AC contained varying concentrations of PT; some vaccines also contained filamentous hemagglutinin (FHA), petractin, and/or agglutinogens. Results. Two hundreds forty children, aged 16 to 21 months and 4 to 6 years, were enrolled at five sites. Significantly less fever, redness, swelling, pain, limp, and use of pain medication were noted following AC compared with WC. Significant increases in antibody to PT were seen following all vaccines. Significant rises in FHA antibody were seen following all WC and the seven AC that contain FHA. Postbooster PT antibody level were similar among the AC groups, regardless of the amount of PT administered (between 3.5 and 25 [mu]g pe dose). The dose of FHA did not affect PT antibody response. Infants primed with WC who were boosted with a monocomponent PT vaccine did not manifest a significant antibody response to FHA. Conclusion. The rate of adverse reactions was not a function of the number of antigens or the antigen quantity in the accellular vaccines, and antibody responses following AC were similar or better than antibody responses following WC. These results support the further evaluation of these vaccines in a larger National Institute of Allergy and Infection Diseases-sponsored study in infants. Pediatrics 1993;93:37-43; acellular pertussis vaccine, whole-cell pertussis vaccine, pertussis vaccine, booster, immunization, pertussis toxoid, filamentous hemagglutinin.