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E L Anderson

Publications and source records attributed to E L Anderson.

At least 37 records · Page 2Linked to original sources

Evaluation of a recombinant hemagglutinin expressed in insect cells as an influenza vaccine in young and elderly adults.

Healthy subjects <45 years old (young adults) or >65 (elderly adults) were randomized in double-blind fashion to receive intramuscularly subvirion trivalent influenza vaccine, placebo, or 15, 45, or 135 microgram of the hemagglutinin (HA) of the influenza A/Beijing/32/92 (H3N2) virus expressed in insect cells by a recombinant baculovirus (rHA0). All vaccines were well tolerated. Both young and elderly adults manifested serum hemagglutination-inhibition, virus neutralizing, and HA-specific IgG ELISA antibody responses to rHA0 vaccine. In young adults given 135 microgram of rHA0, the vaccine was significantly more immunogenic than subvirion influenza vaccine. Elderly adults also had increased antibody responses to 135 microgram of rHA0 compared with subvirion vaccine, but the difference was not statistically significant. These results demonstrate that high-dose rHA0 vaccines are well tolerated and effectively induce both functional and binding serum HA-specific antibody in young and elderly adults.

Adolescent↗

Antibody responses to polysaccharide and polysaccharide-conjugate vaccines after treatment of Hodgkin disease.

OBJECTIVE: To compare the immunogenicity of polysaccharide-conjugate vaccines with that of polysaccharide vaccines in patients previously treated for Hodgkin disease. DESIGN: All patients were immunized with Haemophilus influenzae type b (HIB)-conjugate and 4-valent meningococcal polysaccharide vaccines. Subgroups of patients were randomly assigned to receive either 23-valent pneumococcal polysaccharide vaccine or a 7-valent pneumococcal-conjugate vaccine that links seven pneumococcal serotypes to the outer membrane protein complex of Neisseria meningitidis. PATIENTS: 144 patients who had completed treatment for Hodgkin disease, which had been diagnosed at least 2 years before the study. MEASUREMENTS: Antigen-specific antibody concentrations before and 3 to 6 weeks after immunization; number of persons who achieved anti-HIB antibody concentrations considered to be in the protective range. RESULTS: The geometric mean anti-HIB antibody concentration increased from 1.79 micrograms/mL before immunization to 54.1 micrograms/mL after; the percentage of persons with antibody concentrations in the protective range increased from 62% before immunization to 99% after. Patients immunized with 23-valent pneumococcal vaccine had a geometric mean pneumococcal antibody concentration after immunization (9.15 micrograms/mL) that was similar to that of healthy controls (10.0 micrograms/mL) for the seven serotypes measured. In contrast, patients who received 7-valent pneumococcal-conjugate vaccine had a significantly lower mean response compared with patients who received 23-valent; their geometric mean antibody concentration after immunization was 4.95 micrograms/mL (P = 0.005). CONCLUSION: A single dose of HIB-conjugate vaccine was immunogenic in patients who had completed treatment for Hodgkin disease diagnosed at least 2 years before immunization. In addition, responses to the 23-valent pneumococcal and 4-valent meningococcal vaccines were equivalent to those seen in healthy controls. Finally, patients had a significantly lower response to a single dose of 7-valent pneumococcal-conjugate vaccine than to 23-valent vaccine.

Bacterial Capsules↗

Interchangeability of conjugated Haemophilus influenzae type b vaccines in infants.

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 (CRM197) 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.

Antibodies, Bacterial↗

Influenza A virus vaccines containing purified recombinant H3 hemagglutinin are well tolerated and induce protective immune responses in healthy adults.

This study evaluated the safety, immunogenicity, and protective efficacy of vaccines containing purified recombinant uncleaved hemagglutinin (rHA0) from influenza A/Beijing/32/92 (H3N2) virus. In a randomized, double-blinded trial, 127 adult volunteers were immunized with 15 micrograms of rHA0, 15 micrograms of rHA0 plus alum, 90 micrograms of rHA0, licensed subvirion vaccine, or saline placebo. The rHA0 vaccines caused fewer local adverse reactions than did the commercial subvirion preparation. Neutralizing hemagglutinin-specific antibody responses to 15 micrograms of rHA0 were comparable to those elicited by licensed vaccine, not enhanced by the addition of alum, and significantly increased by raising the rHA0 dose from 15 to 90 micrograms. Compared with placebo recipients, rHA0-vaccinated subjects had significantly lower rates of influenza A (H3N2) virus infection and illness during the epidemic winter season. These results suggest that influenza vaccines containing purified rHA0 may offer an advantage over licensed preparations containing egg-grown antigens by inducing equivalent protective immune responses while being potentially less reactogenic.

Adult↗

A live human parainfluenza type 3 virus vaccine is attenuated and immunogenic in healthy infants and children.

The safety, infectivity, immunogenicity, and phenotypic stability of the cold-passaged (cp) candidate vaccine cp-45, a cold-adapted (ca), temperature-sensitive (ts) mutant of the JS strain of human parainfluenza virus type 3 (HPIV-3), was evaluated in 114 children 6 months to 10 years old in a randomized, placebo-controlled, double-blind trial. The cp-45 vaccine was well tolerated when given intranasally to parainfluenza virus type 3 (PIV-3)-seropositive and -seronegative children. With 10(4) or 10(5) TCID50 of cp-45 vaccine, 86% of seronegative vaccines were infected, 83% of whom shed virus at a mean peak titer of 10(22) pfu/mL. Virus present in respiratory specimens retained the ts phenotype, and each of 86 PIV-3 isolates tested retained both the ca and ts phenotypes. One dose of 10(5) TCID50 of vaccine induced a serum hemagglutination-inhibiting antibody response in 81% of vaccinees; the geometric mean titer was 1:32. These studies indicate that the cp-45 HPIV-3 vaccine is satisfactorily attenuated, infectious, immunogenic, and phenotypically stable and merits further evaluation in infants and young children.

Antibodies, Viral↗

Air pollution and daily mortality in Philadelphia.

Many recent analyses have reported associations between air pollution and mortality in U.S. cities. In this paper, we present the results of regression analyses of daily mortality in Philadelphia during the period 1973-1988. Pollution variables included in the analyses were total suspended particulates (TSP), sulfur dioxide, and ozone. We controlled for the effects of weather on mortality by analyzing mortality separately for each season and explicityly including quintiles of temperature in the regression models. In regression models that consider weather and pollution variables simultaneously, daily mortality is associated with hot days in summer [relative risk (RR) for highest quintile of temperature = 1.07; 95% confidence interval (CI) = 1.04-1.10], and with cold days in spring (RR for lowest quintile of temperature = 1.07; 95% CI = 1.04-1.10), fall (RR for lowest quintile of temperature = 1.05; 95% CI = 1.02-1.08), and winter (RR for lowest quintile of temperature = 1.04; 95% CI = 1.01-1.07). When all three pollution covariates and weather are considered simultaneously in the regression model, ozone is associated with mortality in summer (RR = 1.15; 95% CI = 1.07-1.24) and sulfur dioxide is associated with mortality in spring (RR = 1.19; 95% CI = 1.06-1.33), fall (RR = 1.14; 95% CI = 1.00-1.29), and winter (RR = 1.21; 95% CI = 1.09-1.35), where the relative risks are for incremental changes of 100 parts per billion in ozone and sulfur dioxide on the previous day.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants↗

Comparison of 13 acellular pertussis vaccines: overview and serologic response.

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.

Antibodies, Bacterial↗

Comparison of 13 acellular pertussis vaccines: adverse reactions.

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.

Diphtheria-Tetanus-Pertussis Vaccine↗

A randomized comparison of reactogenicity and immunogenicity of two whole-cell pertussis vaccines.

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.

Antibodies, Bacterial↗

Simultaneous administration of Haemophilus influenzae type b vaccine with acellular or whole-cell pertussis vaccine: effects on reactogenicity and immune responses to pertussis vaccines.

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 b oligosaccharide 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.

Bacterial Proteins↗

The effect of maternal antibody on the serologic response and the incidence of adverse reactions after primary immunization with acellular and whole-cell pertussis vaccines combined with diphtheria and tetanus toxoids.

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.

Antibodies, Bacterial↗

Effect of gender, race, and parental education on immunogenicity and reported reactogenicity of acellular and whole-cell pertussis vaccines.

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 1 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.

Antibodies, Bacterial↗

Defining the key parameters for comparing reactions among acellular and whole-cell pertussis vaccines.

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.

Diphtheria-Tetanus-Pertussis Vaccine↗

Association of reactions after consecutive acellular or whole-cell pertussis vaccine immunizations.

OBJECTIVE: To evaluate the relative frequency of adverse reactions after initial and subsequent immunizations among infants receiving primary immunization with acellular (DTaP) or whole-cell (DTP) pertussis vaccine with diphtheria and tetanus combined. METHODS: We examined the occurrence of common reactions in 2127 infants within 48 hours after immunization at 2, 4, and 6 months with one of 13 DTaP or with Lederle DTP (WCL). Data on at least two consecutive immunizations were available for 357 WCL recipients and 1770 DTaP recipients. For these analyses, reactions evaluated included fever of 100.4 degrees F (38 degrees C) or greater, redness of 21 mm or larger, swelling of 21 mm or larger, moderate or severe pain, moderate or severe fussiness, loss of appetite, drowsiness, and vomiting. RESULTS: With one exception, reactions were approximately 1.5 to 8 times more likely to occur in WCL recipients if the same reaction had been observed at the previous immunization (the single exception was redness after the second immunization). Both initial and repeated reactions were less likely in DTaP than in WCL recipients. As with WCL recipients, risks of repeated reactions in DTaP recipients were higher than the risks of initial reactions (from 2.5 to 24 times as high). CONCLUSION: Reactions after a second or third immunization with either WCL or DTaP vaccine are more likely to occur in infants who had the same reaction after the preceding immunization. Absolute risks of repeated reactions tended to be lower after DTaP vaccine than after the WCL vaccine.

Diphtheria-Tetanus-Pertussis Vaccine↗

Effect of carrier protein priming on antibody responses to Haemophilus influenzae type b conjugate vaccines in infants.

OBJECTIVE: To assess the effect of priming with diphtheria and tetanus toxoid vaccine (DT) at 1 month of age on the anticapsular polyribosylribitol phosphate (PRP) antibody responses of infants vaccinated with Haemophilus influenzae type b polysaccharide-tetanus toxoid conjugate (PRP-T) or PRP oligosaccharide-cross-reactive mutant diphtheria toxin conjugate (HbOC). DESIGN: Randomized controlled trial with serum samples assayed blindly. PARTICIPANTS AND SETTING: Healthy infants enrolled in private pediatric practices; 94 (91%) of 103 infants had prevaccination and postvaccination serum samples available for analysis. INTERVENTIONS: Two groups received DT vaccination at 1 month of age and subsequent injections of PRP-T or HbOC conjugate vaccines at 2, 4, and 6 months of age. The control groups were not vaccinated with DT but received PRP-T or HbOC at the same ages as the carrier-primed groups. Infants in all groups were given a booster injection of unconjugated PRP at 12 months of age to assess induction of immunologic memory. MAIN OUTCOME MEASURE: Concentrations of serum antibody to PRP. MAIN RESULTS: The DT-primed infants given PRP-T had twofold to threefold higher geometric mean anti-PRP antibody responses after one (P < or = .01), two (P < or = .01), or three (P = .06) doses of conjugate vaccine than the infants of the unprimed group. The primed infants also had threefold higher memory antibody responses to the booster PRP injection given at 12 months of age (concentration of 24.4 vs 8.4 micrograms/mL in infants not primed with DT; P < .01). The DT-primed infants given HbOC had twofold to threefold higher antibody responses after one (P = .07) or two (P < .01) doses of conjugate vaccine than the unprimed HbOC group, but there were no significant differences after the third dose of conjugate vaccine or after the PRP booster injection. CONCLUSIONS: Vaccination with DT at 1 month of age increases the magnitude of the anti-PRP antibody responses to conjugate vaccination. With HbOC, the effect of carrier priming was present for up to 6 months of age, whereas in infants vaccinated with PRP-T, enhanced immunity was present for at least 12 months.

Antibodies, Bacterial↗

Acellular pertussis vaccines in infants: evaluation of single component and two-component products.

Two acellular pertussis vaccines, one containing only LPF toxoid (25 micrograms) and the other containing LPF toxoid (25 micrograms) and FHA (25 micrograms) and each combined with diphtheria and tetanus toxoids, were evaluated in two groups of 25 infants. A third group of 25 infants served as controls and received a DTP whole-cell pertussis vaccine. Infants given either acellular pertussis vaccine had significantly fewer local and systemic reactions than infants given whole-cell vaccine. Among the three vaccine groups, infants given the LPF vaccine (single component) had the highest concentration of antibody to LPF after three immunizations. Infants receiving the LPF/FHA vaccine (two-component) had the highest concentration of antibody to FHA after three immunizations. Infants vaccinated with the two-component vaccine had a significantly lower serological response to LPF than infants given the single component vaccine, as measured by either enzyme-linked immunosorbent assay or CHO cell assay. Further studies are necessary to determine why differences in immunogenicity of the two investigational vaccines occurred.

Antibodies, Bacterial↗

Multidose, live attenuated, cold-recombinant, trivalent influenza vaccine in infants and young children.

Twenty-two healthy infants and children received either cold-recombinant, trivalent influenza vaccine or placebo in a three-dose vaccine trial. Most (82%) who received vaccine were seronegative to all three vaccine strains (10(6) TCID50/dose each): A/Kawasaki/9/86 (H1N1), A/Los Angeles/2/87 (H3N2), and B/Yamagata/16/88. Vaccine was administered intranasally at time 0 and 2 and 4 months later. The vaccine was well tolerated and immunogenic when administered in a multidose regimen. The first dose stimulated antibody to H1, H3, and B in 59%, 94%, and 35% of vaccinees, respectively, by hemagglutination inhibition (HAI) or ELISA. After two doses of vaccine, 93%, 93%, and 80% had antibody by HAI or ELISA to H1, H3, and B, respectively. Most vaccinees (67%) responded to all three viruses after two doses of vaccine. The third dose contributed little to the vaccine's immunogenicity. Multidose trivalent influenza vaccine is safe and induces an immune response in most vaccinees after two doses.

Dose-Response Relationship, Immunologic↗