Dose-ranging study of a single injection of pneumococcal conjugate vaccine (1 ×, 2 ×, or 4 ×) in healthy subjects aged 70 years or older.

Healthy adults aged ≥ 70 years (N=443) with no history of pneumococcal vaccination received 7- or 9-valent pneumococcal conjugate vaccine (PCV7 or PCV9) at 1 × (PCV7 only), 2 × (PCV7+PCV9), or 4 × (2 × PCV7+2 × PCV9) dosage in a randomised, open-label study evaluating pneumococcal protein conjugate vaccine (PnC). Controls received 23-valent pneumococcal polysaccharide vaccine (PPV). Both geometric mean concentration enzyme-linked immunosorbent assay and opsonophagocytic activity antibody titres assessed 1 month after vaccination were significantly increased over baseline titres for all PCV7 serotypes, with a trend toward a dose-dependent immune response. Local reactions for the 4 × dose, but not the 2 × dose, were statistically significantly higher than for the 1 × dose. No treatment-related serious adverse events occurred.

Comparison of pneumococcal conjugate polysaccharide and free polysaccharide vaccines in elderly adults: conjugate vaccine elicits improved antibacterial immune responses and immunological memory.

BACKGROUND: High functional antibody responses, establishment of immunologic memory, and unambiguous efficacy in infants suggest that an initial dose of conjugated pneumococcal polysaccharide (PnC) vaccine may be of value in a comprehensive adult immunization strategy. METHODS: We compared the immunogenicity and safety of 7-valent PnC vaccine (7vPnC) with that of 23-valent pneumococcal polysaccharide vaccine (PPV) in adults >/=70 years of age who had not been previously vaccinated with a pneumococcal vaccine. One year later, 7vPnC recipients received a booster dose of either 7vPnC (the 7vPnC/7vPnC group) or PPV (the 7vPnC/PPV group), and PPV recipients received a booster dose of 7vPnC (the PPV/7vPnC group). Immune responses were compared for each of the 7 serotypes common to both vaccines. RESULTS: Antipolysaccharide enzyme-linked immunosorbent assay antibody concentrations and opsonophagocytic assay titers to the initial dose of 7vPnC were significantly greater than those to the initial dose of PPV for 6 and 5 of 7 serotypes, respectively (P < .01 and P < .05, respectively). 7vPnC/7vPnC induced antibody responses that were similar to those after the first 7vPnC inoculation, and 7vPnC/PPV induced antibody responses that were similar to or greater than antibody responses after administration of PPV alone; PPV/7vPnC induced significantly lower antibacterial responses, compared with those induced by 7vPnC alone, for all serotypes (P < .05). CONCLUSION: In adults, an initial dose of 7vPnC is likely to elicit higher and potentially more effective levels of antipneumococcal antibodies than is PPV. In contrast with PPV, for which the induction of hyporesponsiveness was observed when used as a priming dose, 7vPnC elicits an immunological state that permits subsequent administration of 7vPnC or PPV to maintain functional antipolysaccharide antibody levels.

Design of a group-randomized Streptococcus pneumoniae vaccine trial.

A group-randomized, double-masked, phase III trial of a Streptococcus pneumoniae conjugate vaccine is being conducted in American Indian populations in the southwestern United States. Approximately 9000 infants will be enrolled in the primary efficacy cohort with vaccine allocation determined by community of residence. The trial is designed to continue until 48 cases of invasive pneumococcal disease due to vaccine serotypes have accumulated. Thirty-eight geographically and socially distinct areas were randomized within blocks formed by population size and geographic location. This design affords the opportunity to capture the effects of herd immunity (indirect effects) by estimating the impact of the vaccine intervention on nonimmunized infants. Group-randomized trials have challenging design and analysis features, many of which are discussed here in the context of the first such trial designed to lead to licensure of a drug or biologic in the United States.

Safety and immunogenicity of four doses of Neisseria meningitidis group C vaccine conjugated to CRM197 in United States infants.

BACKGROUND: Following widespread use of conjugate pneumococcal vaccine, Neisseria meningitidis likely will become the leading cause of bacterial sepsis and meningitis in US children. This report describes the safety and immunogenicity in US children of four consecutive doses of a meningococcal group C vaccine conjugated to CRM197 via reductive amination (MnCC). METHODS: One hundred six healthy 2-month-old infants received MnCC at 2, 4 and 6 months of age in a randomized, controlled double blind study; children in the other treatment arm were given a 7-valent conjugate pneumococcal vaccine. Parents reenrolled 64 of these children at 12 to 15 months to receive a fourth dose of MnCC. Routine childhood vaccines, including DTP, were coadministered. Temperatures and symptoms were recorded for 3 days after each immunization. Serum enzyme-linked immunosorbent assay IgG and bactericidal antibodies were measured prevaccination and before and 1 month after Doses 3 and 4. RESULTS: Moderate to severe local reactions, defined as erythema or induration > or =2.4 cm or pain that interfered with limb movement was reported after 0 to 3.2% of MnCC injections, depending on the reaction and dose. Fever occurred in 23 to 37% of children, but the contribution of MnCC to the febrile reactions is unknown. Geometric mean concentrations of IgG antibody to group C meningococcal polysaccharide were 3.72 microg/ml after Dose 3 and 8.03 microg/ml after the booster. Geometric mean functional serum bactericidal antibody titers after Doses 3 and 4 were 1:463 and 1:2341, respectively. One hundred percent of children had a serum bactericidal antibody titer of > or =1:64 after three doses and > or = 1:128 after the booster. CONCLUSIONS: The MnCC vaccine had an acceptable safety profile and generated high titers of bactericidal antibody in immunized US infants and toddlers. It appears to be an attractive candidate vaccine for the prevention of serogroup C meningococcal disease in young children.

Efficacy, safety and immunogenicity of heptavalent pneumococcal conjugate vaccine in children. Northern California Kaiser Permanente Vaccine Study Center Group.

OBJECTIVE: To determine the efficacy, safety and immunogenicity of the heptavalent CRM197 pneumococcal conjugate vaccine against invasive disease caused by vaccine serotypes and to determine the effectiveness of this vaccine against clinical episodes of otitis media. METHODS: The Wyeth Lederle Heptavalent CRM197 (PCV) was given to infants at 2, 4, 6 and 12 to 15 months of age in a double blind trial; 37,868 children were randomly assigned 1:1 to receive either the pneumococcal conjugate vaccine or meningococcus type C CRM197 conjugate. The primary study outcome was invasive disease caused by vaccine serotype. Other outcomes included overall impact on invasive disease regardless of serotype, effectiveness against clinical otitis media visits and episodes, impact against frequent and severe otitis media and ventilatory tube placement. In addition the serotype-specific efficacy against otitis media was estimated in an analysis of spontaneously draining ears. RESULTS: In the interim analysis in August, 1998, 17 of the 17 cases of invasive disease caused by vaccine serotype in fully vaccinated children and 5 of 5 of partially vaccinated cases occurred in the control group for a vaccine efficacy of 100%. Blinded case ascertainment was continued until April, 1999. As of that time 40 fully vaccinated cases of invasive disease caused by vaccine serotype had been identified, all but 1 in controls for an efficacy of 97.4% (95% confidence interval, 82.7 to 99.9%), and 52 cases, all but 3 in controls in the intent-to-treat analysis for an efficacy of 93.9% (95% confidence interval, 79.6 to 98.5%). There was no evidence of any increase of disease caused by nonvaccine serotypes. Efficacy for otitis media against visits, episodes, frequent otitis and ventilatory tube placement was 8.9, 7.0, 9.3 and 20.1% with P < 0.04 for all. In the analysis of spontaneously draining ears, serotype-specific effectiveness was 66.7%. CONCLUSION: This heptavalent pneumococcal conjugate appears to be highly effective in preventing invasive disease in young children and to have a significant impact on otitis media.

Safety and immunogenicity of heptavalent pneumococcal CRM197 conjugate vaccine in infants and toddlers.

OBJECTIVES: The objectives of this study were (1) to determine the safety and immunogenicity of heptavalent pneumococcal CRM197 conjugate (PNCRM7) vaccine in infants and (2) to determine the effect of concurrent hepatitis B immunization during the primary series and the effect of concurrent diphtheria and tetanus toxoid and acellular pertussis [DTaP (ACEL-IMUNE)] and conjugate CRM197 Haemophilus influenzae type b [HbOC (HibTITER) immunization at time of the booster dose on the safety and immunogenicity of PNCRM7and these other concurrently administered vaccines. METHODS: This was a randomized double-blinded study in 302 healthy infants in the Northern California Kaiser Permanente (NCKP) Health Plan. Infants received either PNCRM7 vaccine or meningococcal group C conjugate vaccine as a control at 2, 4 and 6 months of age and a booster at 12 to 15 months of age. Study design permitted the evaluation of immunology and safety of concurrent administration of routine vaccines. Antibody titers were determined on blood samples drawn before and 1 month after the primary series and the booster dose. RESULTS: After the third dose of PNCRM7 geometric mean concentrations (GMCs) ranged from 1.01 for serotype 9V to 3.72 microg/ml for serotype 14. More than 90% of all subjects had a post-third dose titer of > or =0.15 microg/ml for all serotypes, and the percentage of infants with a post-third dose titer of > or =1.0 microg/ml ranged from 51% for type 9V to 89% for type 14. After the PNCRM7 booster dose, the GMCs of all seven serotypes increased significantly over both post-Dose 3 and pre-Dose 4 antibody levels. In the primary series there were no significant differences in GMCs of pneumococcal antibodies between the subjects given PN-CRM7 alone or concurrently with hepatitis B vaccine. At the toddler dose concurrent administration of PNCRM7 and DTaP and HbOC resulted in a near conventional threshold for statistical significance of a post-Dose 4 GMC for serotype 23F [alone 6.75 mirog/ml vs. concurrent 4.11 microg/ml (P = 0.057)] as well as significantly lower antibody GMCs for H. influenza polyribosylribitol phosphate, diphtheria toxoid, pertussis toxin and filamentous hemagglutinin. For all antigens there were no differences between study groups in defined antibody titers that are considered protective. CONCLUSION: We conclude that PNCRM7 vaccine was safe and immunogenic. When this vaccine was administered concurrently at the booster dose with DTaP and HbOC vaccines, lower antibody titers were noted for some of the antigens when compared with the antibody response when PNCRM7 was given separately. Because the GMCs of the booster responses were all generally high and all subjects achieved similar percentages above predefined antibody titers, these differences are probably not clinically significant.

Immunogenicity and safety of a monovalent, multicomponent acellular pertussis vaccine in 15 month-6-year-old German children. Monovalent Acellular Pertussis Vaccine Study Group.

Immunization against pertussis has been re-recommended for healthy children in Germany in 1991. In addition the former restriction of immunizing only in the first 2 years of life was abolished. In children born before 1991 immunization rates against pertussis were 15% or less. With the new recommendations physicians are now faced with an increasing demand of parents for catch-up vaccinations in these children. Since they were immunized against diphtheria and tetanus previously monovalent pertussis vaccines are needed for this indication. Therefore a monovalent, multicomponent acellular pertussis vaccine was studied in 249 German children 15 months to 6 years of age. Three doses were administered at 6-10 week intervals. Reactogenicity and antibody responses against the vaccine antigens pertussis toxin (PT), filamentous haemagglutinin (FHA), 69-kd antigen (pertactin) and fimbriae-2 (agglutinogen) were investigated. Local and systemic reactions were minimal in frequency and severity. Antibody responses against all vaccine antigens were pronounced with 93%-100% of vaccinees demonstrating at least four fold titre rises above pre-immunization after the third dose. These findings indicate that this monovalent, multicomponent acellular pertussis vaccine with excellent immunogenicity and low reactogenicity is an appropriate candidate for closing immunization gaps in older children in countries with previously low vaccination rates against pertussis. Based on the results of this study the monovalent acellular pertussis vaccine was licensed in Germany in January 1994.

Comparative study of Lederle/Takeda acellular and Lederle whole-cell pertussis-component diphtheria-tetanus-pertussis vaccines in infants in Germany.

In preparation for a large efficacy trial in Germany, a pilot study was initiated in December 1990. In this study 149 infants were enrolled; with double-blind randomization 75 received Lederle/Takeda acellular pertussis component diphtheria-tetanus-pertussis vaccine (APDT) and 74 received Lederle whole-cell pertussis component diphtheria-tetanus-pertussis vaccine (DTP). The mean age at first dose was 3.5 months, and the second and third doses followed at 6-week intervals. Reactions were relatively mild with both vaccines; in general they were less frequent following APDT. The IgG antibody responses to lymphocytosis promoting factor (LPF) and fimbriae-2 were similar in both groups whereas the responses to pertactin and filamentous haemagglutinin (FHA) were greater in APDT recipients. DTP recipients had greater responses to tetanus and diphtheria toxoids. When age of first dose was examined (8-12 weeks versus 16-20 weeks), it was found that young age had a suppressive effect on antibody responses in DTP but not APDT recipients to LPF toxoid, pertactin, fimbriae-2, and tetanus and diphtheria toxoids. High values of transplacentally acquired antibody lessened the response to LPF toxoid and tetanus toxoid in DTP recipients and to tetanus toxoid in APDT vaccinees. The IgG immune response to LPF toxoid, FHA and fimbriae-2 was found to be more uniform in APDT recipients than in DTP vaccinees. An IgA antibody response to fimbriae-2 was noted in 13% of DTP recipients but in no APDT vaccinees. The broad immunogenicity and mild reactogenicity of this APDT vaccine justifies its use in the German efficacy trial.

Safety and immunogenicity of a combined diphtheria, tetanus, pertussis and Haemophilus influenzae type b vaccine in young infants.

OBJECTIVE: To study the safety and immunogenicity of a combined diphtheria-tetanus-pertussis (DTP)-Haemophilus influenzae type b (HbOC) vaccine (TETRAMUNE) in infants as young as 2 months of age as compared to separate administration of DTP and HbOC. METHODS: Two-month-old infants were randomized to receive three doses 2 months apart of either DTP-HbOC as a single 0.5-mL injection or to receive 0.5 mL of DTP and HbOC concurrently in separate legs. Local and systemic adverse reactions were monitored within 72 hours of each immunization, and immunogenicity of each of the four vaccine components was measured. RESULTS: The incidence of both local and systemic adverse events following the tetravalent vaccine was similar to the incidence following separate vaccine administration. After three doses of vaccine, the response to each of the vaccine components was higher in the combined vaccine when compared to separate administration. In the case of the Haemophilus influenzae type b component, this enhancement was also seen after two doses. The response to the combined vaccine was consistent among the three lots tested as was the enhancement over separate administration. CONCLUSIONS: The DTP-HbOC vaccine was safe and immunogenic in young infants and was generally more immunogenic than separate vaccination with DTP and HbOC. The use of such a combined vaccine reduces the number of injections given to young infants by half and is an important step toward improving vaccine delivery.

Safety of combined oligosaccharide conjugate Haemophilus influenzae type b (HbOC) and whole cell diphtheria-tetanus toxoids-pertussis vaccine in infancy. The Kaiser Permanente Pediatric Vaccine Study Group.

The safety of the combined oligosaccharide conjugate Haemophilus influenzae (Hib) type b (HbOC) and whole cell diphtheria-tetanus toxoids-pertussis (DTP) vaccine (Tetramune, HbOC-DTP; Lederle) in infancy was evaluated in 6644 recipients of this vaccine and compared with 3914 recipients of separate injections of whole cell DTP and HbOC vaccines when given as a three dose regimen to infants at 2, 4 and 6 months of age in each group. Of the total number of infants in the study, a subset of 1435 were enrolled into the study and then randomly assigned to receive either the Hib-DPT combined vaccine or the separate components. This subset was used to assess local and systemic side effects which were evaluated utilizing telephone interviews 48 to 72 hours after vaccine. The remaining children in the study population were enrolled in a nonrandomized manner. For these children parents were offered the experimental Hib-DPT vaccine and refusers were given HbOC and DTP. Both of these groups of children as well as the randomized subset described above were used to assess rates of episodes of hospitalization, emergency room utilization and sudden infant death syndrome in HbOC-DTP recipients and children who received HbOC and DTP separately. Immunogenicity was evaluated in 123 children by collection of a single serum sample 30 days after the third dose of HbOC-DTP. The observed immunogenicity was comparable to that observed in other recent studies for HbOC and DTP component antigens. The profile of local and systemic side effects observed was virtually identical to that observed after DTP plus HbOC given separately.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous administration of a diphtheria and tetanus toxoids and acellular pertussis vaccine with measles-mumps-rubella and oral poliovirus vaccines.

OBJECTIVE: To compare the safety and immunogenicity of Lederle Laboratories' (Pearl River, NY) diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccine with diphtheria and tetanus toxoids and whole-cell pertussis (DTwP) vaccine when administered simultaneously with measles-mumps-rubella (MMR) vaccine and trivalent oral poliovirus (OPV) vaccine at 15 to 16 months of age. DESIGN: Randomized and double-blind. SETTING: Two general pediatric practices. PARTICIPANTS: Ninety-seven infants, aged 15 to 16 months, who had received three previous DTwP immunizations. SELECTION PROCEDURES AND INTERVENTIONS: Healthy children received the DTaP or DTwP vaccine. Infants received the MMR vaccine at a separate site and the OPV vaccine concurrently. Blood was obtained on day 0 and at 6 weeks. Adverse events were recorded by parents at specified times after immunization. MEASUREMENTS/RESULTS: Within 3 days of immunization, DTaP vaccine recipients had less fever, drowsiness, and irritability (P = .01, .04, .01, respectively). They also experienced less tenderness, erythema, and induration (.001, .001, and .002, respectively). There was no difference in the frequency of adverse reactions 6 to 14 days after immunization. Enzyme-linked immunosorbent assays were used to determine all antibody values. Antibody responses to filamentous hemagglutinin and pertussis toxoid were significantly greater in the DTaP group (P = .0001 and .02, respectively). Immune responses to the other measured antigens were similar. CONCLUSIONS: Simultaneous administration of the Lederle DTaP with MMR and OPV vaccines did not interfere with antibody response to pertussis antigens measured or measles, mumps, or rubella viruses and was associated with fewer local and systemic adverse events during the first 3 days following immunization when compared with the simultaneous administration of the DTwP, OPV, and MMR vaccines. We conclude that the DTaP vaccine can be administered at 15 months of age concurrently with the MMR and OPV vaccines.

Unrecognized pertussis infection in adolescents.

Little information is available regarding the level of immunity to Bordetella pertussis among adolescents. We measured serum antibodies in 156 healthy adolescents to the following pertussis antigens: pertussis toxin, filamentous hemagglutinin, and 69-kd outer membrane protein. In an attempt to identify intercurrent pertussis infections, we also obtained a total of 43 repeated samples during the following 5 years. Using a 50% or greater rise in IgG enzyme-linked immunosorbent assay titers to define seroconversion, we found an annual incidence of 6.1%; by alternative definitions of seropositivity, the predicted annual incidence of infection ranged from 1.2% to 8.2%. These data suggest that infection with B pertussis is common in the adolescent population.

Adult immunization with acellular pertussis vaccine.

OBJECTIVE: To evaluate the safety and immunogenicity in adults of several different concentrations of an acellular pertussis vaccine. DESIGN: Double-blind, randomized, placebo-controlled trial. SETTING: Medical center immunization clinic. PARTICIPANTS: One hundred eighteen healthy adult volunteers. INTERVENTIONS: Participants received standard adult tetanus-diphtheria vaccine alone or combined with full-strength, half-strength, or quarter-strength concentrations of a currently licensed acellular pertussis vaccine used for booster doses in young children. Full-strength vaccine contained 40 micrograms of pertussis proteins, consisting of 86% filamentous hemagglutinin, 8% pertussis toxin, 4% 69-kd outer-membrane protein, and 2% agglutinogens. MAIN OUTCOME MEASURES: Local and systemic reactions were assessed for 14 days after vaccination. Serum samples for antibody assay were obtained before, 1 month after, and 1 year after immunization. RESULTS: Adverse reactions were few and minor and did not differ in frequency or severity among the four study groups. The groups receiving acellular pertussis vaccine showed strong antibody responses to pertussis antigens, which did not significantly differ by concentration of vaccine. After 1 year, levels of antibody to pertussis had declined by approximately 50% but remained substantially higher than preimmunization levels. The four groups did not differ in antibody responses to tetanus or diphtheria toxoids. CONCLUSIONS: Routine reimmunization of adults with a vaccine containing acellular pertussis antigens in addition to diphtheria and tetanus toxoids can substantially enhance pertussis antibody levels without an increase in adverse reactions or diminution in response to the diphtheria and tetanus components. Such a program might materially reduce respiratory illness among both adults and children.

Safety and immunogenicity of acellular pertussis vaccine, combined with diphtheria and tetanus as the Japanese commercial Takeda vaccine, compared with the Takeda acellular pertussis component combined with Lederle's diphtheria and tetanus toxoids in two-, four- and six-month-old infants.

A double blind, randomized, controlled trial compared the safety and immunogenicity of an acellular pertussis vaccine formulated at Lederle using the Takeda acellular pertussis component combined with Lederle diphtheria and tetanus toxoids vaccines (APDT), with the commercially available Japanese Takeda vaccine (APDT-T/J) as a three-dose series to 2-, 4-, and 6-month-old children. Sera were analyzed for antibody to pertussis antigens: lymphocytosis-promoting factor; filamentous hemagglutinin; 69-kDa outer membrane protein; pertussis agglutinogens; neutralizing antibodies to LPF; and to diphtheria and tetanus toxoids. Information concerning local reactions and systemic events were collected daily for 10 days postimmunization. The overall reaction rate was low for both groups. There were no reactions that contraindicated subsequent vaccine and no serious adverse events. For local reactions statistically significant differences between the groups were seen only for a greater incidence of induration in the APDT group at 2 months (12% vs. 0%, P < 0.01), and at 4 months (8% vs. 0%, P = 0.4) compared to the APDT-T/J group. Of the few systemic reactions the only statistically significant difference between the vaccine groups was a greater incidence of fretfulness in the APDT group after the initial immunization (12% vs. 2%, P = 0.05). There were no statistically significant differences in the immune response between the two vaccines at the 7-month visit. We conclude that APDT is equivalent to the commercially available Takeda vaccine (APDT-T/J).

Clinical trials in the United States and Japan with the Lederle-Takeda and Takeda acellular pertussis-diphtheria-tetanus (APDT) vaccines. The Multicenter APDT Vaccine Study Groups.

The results of the following studies are reported: a longitudinal double blind trial comparing Lederle-Takeda APDT vaccine with Lederle DTP vaccine in two, four and six month old infants; two double blind similar APDT vs DTP trials in 18 month old and four to six year old children; a large longitudinal open trial with APDT in two, four and six month old infants and a household contact efficacy trial with Takeda APDT in Japan. APDT vaccine recipients had a lesser frequency and less severe reactions than whole cell vaccine recipients. Antibody responses to lymphocytosis-promoting factor and agglutinogens were higher in DTP recipients; APDT recipients had a better serologic response to filamentous hemagglutinin. Equivalent 69K protein antibody responses were seen. Vaccine efficacy in the household contact study was 98% (95% CI = 84% to 99%) against classical pertussis and 81% (95 CI = 64% to 90%) if all respiratory illnesses are considered.

Neonatal sepsis at The Johns Hopkins Hospital, 1969-1975: bacterial isolates and clinical correlates.

The experience with neonatal sepsis at The Johns Hopkins Hospital during 1969-1975 was reviewed. Major pathogens included Escherichia coli, group B streptococcus, other streptococci, and Klebsiella. Nineteen percent of coliform isolates were kanamycin-resistant. The frequency of recovery of E. coli was increased in early-onset sepsis, and the frequency of recovery of Klebsiella was increased in late-onset sepsis. The mortality rate was 23%. The frequency of recovery of E. coli was increased in fatal cases, and mortality was highly correlated with the presence of gastrointestinal catastrophe. Ampicillin and gentamicin are the initial antibiotics of choice for neonatal sepsis at this institution; a penicillinase-resistant penicillin should be added when Staphylococcus aureus involvement is likely, and addition of chloramphenicol or clindamycin should be considered for infants at increased risk for Bacteroides fragilis sepsis.