Vaccines consisting of periodate-cleaved oligosaccharides from the capsule of Haemophilus influenzae type b coupled to a protein carrier: structural and temporal requirements for priming in the human infant

Reducing oligosaccharides from the Haemophilus influenzae type b capsular polymer (PRP) coupled by reductive amination to diphtheria toxoids (DTd) had been shown to elicit potentially protective serum anti-PRP antibodies (Ab) in infants too young for an adequate response to PRP vaccine. Here we report that cleavage of PRP with periodate gives antigenic oligosaccharides that couple with high efficiency. DTd-coupled saccharides of mean length eight or 20 repeat units (Dpo8 and Dpo20, respectively) were tested for immunogenicity in young adults (single injection) and in infants 9 to 15 mo old who received a sequence of primary (1 degree) and secondary (2 degrees) injections. Both vaccines consistently induced high anti-PRP Ab responses in adults. In infants, Dpo8 elicited only modest anti-PRP responses, whereas Dpo20 gave consistently high titers; post-2 degrees responses were higher when the interval between 1 degree and 2 degrees injections was 6 to 14 wk than with an interval of 2 to 4 wk. Thus with this type of immunogen, priming responses in infancy has more stringent structural requirements than does triggering responses in adults, and the priming appears to maximize more slowly than the Ab level.

Vaccines consisting of periodate-cleaved oligosaccharides from the capsule of Haemophilus influenzae type b coupled to a protein carrier: structural and temporal requirements for priming in the human infant

Reducing oligosaccharides from the Haemophilus influenzae type b capsular polymer (PRP) coupled by reductive amination to diphtheria toxoids (DTd) had been shown to elicit potentially protective serum anti-PRP antibodies (Ab) in infants too young for an adequate response to PRP vaccine. Here we report that cleavage of PRP with periodate gives antigenic oligosaccharides that couple with high efficiency. DTd-coupled saccharides of mean length eight or 20 repeat units (Dpo8 and Dpo20, respectively) were tested for immunogenicity in young adults (single injection) and in infants 9 to 15 mo old who received a sequence of primary (1 degree) and secondary (2 degrees) injections. Both vaccines consistently induced high anti-PRP Ab responses in adults. In infants, Dpo8 elicited only modest anti-PRP responses, whereas Dpo20 gave consistently high titers; post-2 degrees responses were higher when the interval between 1 degree and 2 degrees injections was 6 to 14 wk than with an interval of 2 to 4 wk. Thus with this type of immunogen, priming responses in infancy has more stringent structural requirements than does triggering responses in adults, and the priming appears to maximize more slowly than the Ab level.

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

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

Immunization of 2-month-old infants with protein-coupled oligosaccharides derived from the capsule of Haemophilus influenzae type b

We studied an immunogen consisting of oligosaccharides derived from Haemophilus influenzae type b capsular polysaccharide (PRP) coupled to CRM197, a nontoxic relative of diphtheria toxin. Subcutaneous injections were given to eight subjects at ages 2, 4, and 6 months, simultaneously with conventional diphtheria-tetanus-pertussis (DTP) vaccine. After the first immunization, total serum anti-PRP antibodies declined in all subjects, but increased in most after the second immunization and after the third in seven of seven subjects analyzed. In these seven infants, the geometric mean level at age 9 months (0.73 micrograms/ml) exceeded by at least 40 times the means of historical control groups given DTP only or DTP plus (uncoupled) PRP vaccine. An isotype-specific assay showed that IgM antibodies increased after the first immunization with the coupled vaccine in all eight infants. Against the background of declining maternal IgG antibody, elevations in IgG antibody were detected after the second or third immunization in six of the eight. These six at age 9 to 11 months were immunized with (uncoupled) PRP vaccine, and a "boost" in anti-PRP antibody, including an IgG component, was found.

Immunological paralysis to pneumococcal polysaccharide in man

A 9-month-old infant had severe pneumococcal meningitis and for the next two years showed immunological paralysis to the causal serotype. He remained normally responsive to a protein antigen (tetanus toxoid) and to polysaccharide antigens (Haemophilus influenzae type b capsule and pneumococcal capsule antigens other than the infecting/paralysing serotype). By the fourth year of life the child was spontaneously producing antibody to the infecting/paralysing pneumococcal serotype, at which time rechallenge with the previously tolerising antigen resulted in a secondary response. The occurrence of pneumococcal immunological paralysis in man is therefore validated.

Immunogens consisting of oligosaccharides from the capsule of Haemophilus influenzae type b coupled to diphtheria toxoid or the toxin protein CRM197

Haemophilus influenzae type b (Hib) capsular polysaccharide (PRP) was selectively hydrolyzed to reducing oligosaccharides, and the fraction containing 3-10 ribosylribitolphosphate repeating units (VS) was conjugated by reductive amination to diphtheria toxin (DTx), its nontoxic derivative CRM197 (Dcr), or diphtheria toxoid (DTd). Conjugate DTx-VS retained approximately 1% of native toxicity, which was eliminated by treatment with formalin. Immunization of rabbits with the conjugates elicited antibody (Ab) to PRP and to DTx but not to a model for the linkage determinant. Human adults given single subcutaneous injections had rises in serum Ab to PRP and in bactericidal activity in vitro; the Ab protected infant rats challenged with Hib. Adults had rises also in Ab to DTd, and these Ab protected rabbits against DTx. A series of two injections of the conjugates Dcr-VS and DTd-VS was tested in infants beginning at 19-23 mo of age. Rises in anti-PRP Ab after the primary resembled the rises after PRP vaccine. In contrast to PRP, the conjugates elicited large rises after the secondary vaccinations and a substantial IgG component. Development of bactericidal activity paralleled the rises in anti-PRP Ab. Secondary rises after Dcr-VS were higher than after DTd-VS. In infants 12-16 mo of age, Dcr-VS (but not DTd-VS) elicited strong primary and secondary Ab responses that included IgG and bactericidal activity. Both conjugates produced consistent rises in Ab to DTd.

Enhanced nasopharyngeal colonization of rats by piliated Haemophilus influenzae type b

Piliated Haemophilus influenzae type b strains display an enhanced adherence to human epithelial cells in vitro. However, clinical isolates, even from mucosal sites, are seldom piliated, although piliated populations can be selected from them. Experiments with rats have led some authors to suggest that piliation does not implement colonization by H. influenzae type b. Piliated populations were obtained from 35 strains by selection for adherence to human erythrocytes. One strain, H. influenzae H305, simultaneously acquired an increased adherence to rat erythrocytes and buccal epithelial cells. In contrast to other strains, H. influenzae H305 in piliated form was more effective than in nonpiliated form in the colonization of rats by intranasal inoculation. After the piliated inoculum, however, the colonies cultured from the nasal washes were negative for erythrocyte adherence. Thus, piliated H. influenzae type b strains have an apparent advantage to initiating colonization in the rat model but may give rise to nonpiliated progeny that are more readily cultivable from the mucosal surface.

Hemophilus influenzae type b disease. An epidemiologic study with special reference to day-care centers

Day-care centers are a relatively new phenomena of American society that bring together large numbers of young children susceptible to contagious disease. This study examines the incidence and risk factors of endemic Hemophilus influenzae type b disease both in the general population and in day-care attendees in Monroe County, New York, for 1982 and 1983. The attack rate in the general population (excluding day-care attendees) was highest in children younger than 1 year (131.9 cases per 100,000 per year) and in those 1 to 2 years old (75.7 cases per 100,000 per year) compared with older children. The relative risk for day-care attendees was much greater than that of the general population. It was 12.3 times greater for children younger than 1 year, 7.2 times greater for those 1 to 2 years old, and 3.8 times greater for those 2 to 3 years old. We conclude that children attending day-care facilities face a substantial increased risk of contracting invasive H influenzae type b disease. Efforts to prevent susceptibility and contagious spread of this disease in this population seem necessary.

Adherence of Haemophilus influenzae to human buccal and pharyngeal epithelial cells: relationship to pilation

An improved understanding of the role of pili in adherence of Haemophilus influenzae type b to human epithelial cells (EC) would enhance knowledge of the pathogenesis of H. influenzae b infections. In this study a highly sensitive in-vitro assay allowed the quantitative assessment of H. influenzae b adherence to EC. The degree of adherence was influenced by incubation time, temperature, bacteria/EC ratio, EC type and the growth phase of the bacteria. Most serially subcultured (SC) capsular type-b strains originally isolated from cerebrospinal fluid, blood, nasopharynx or throat gave similar low degrees of adherence, as did representative single strains of capsular types a, c, d, e and f. SC non-capsulated H. influenzae strains adhered in significantly greater numbers than most SC capsulated strains (p less than 0.001). One SC type-b strain isolated from a throat, with stable piliation, adhered in very high numbers despite capsulation. Piliated subpopulations selected from type-b capsulated strains adhered in greater numbers than did their parent strains. These data suggest that capsulation of H. influenzae is a deterrent to adherence of the bacteria to EC. However, the presence of pili may allow type-b organisms to overcome the effects of capsulation.

Lipopolysaccharide subtypes of Haemophilus influenzae type b from an outbreak of invasive disease

Thirty isolates of Haemophilus influenzae type b were obtained during an outbreak of invasive H. influenzae type b disease and were classified by the electrophoretic profile of their lipopolysaccharide (LPS). The LPS was extracted by a rapid micromethod and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining. The isolates could be divided into 1 of 14 subtypes based on the profile of two to four bands. No subtype was predominant. However, all isolates obtained from duplicate sites of the same individual were of the same subtype. Isolates obtained from two patients (6 weeks apart) who attended the same day-care center differed in LPS subtype but were identical in their major outer membrane protein electrophoretic profile. Nasopharyngeal cultures were obtained from healthy children, their immediate families, and employees of the day-care center. Of 13 H. influenzae isolates examined from these contacts, only 1 was type b, which was obtained from a day-care worker and had the same LPS subtype and major outer membrane protein electrophoretic profile as one of the disease isolates. The remaining nasopharyngeal isolates were untypable, and most, but not all, were different in LPS pattern. Thus, LPS subtyping of H. influenzae type b may be useful in examining the predominance or transmission of a strain during an outbreak and may distinguish some strains not differentiated by outer membrane protein pattern.

Neonatal passive immunization by maternal vaccination

An old concept--passively immunizing a fetus by actively immunizing (vaccinating) its mother--is reevaluated in light of 50 years of data. The history and data reviewed here suggest that this concept is one whose time has come for active modern research and clinical use. In Third World countries, this concept already has provided significant reduction in morbidity and mortality from neonatal infections such as tetanus. Some other neonatal and infant infections--heretofore life-threatening--may now have a practical method for prevention. These include group B beta-streptococcal sepsis and Hemophilus influenzae meningitis.

Mucosal antibody response to parenteral vaccination with Haemophilus influenzae type b capsule

The simultaneous serum and mucosal antibody response to parenteral vaccination with the Haemophilus influenzae type b (Hib) polysaccharide capsule (PRP) was evaluated in a group of 10 children and nine adults. All subjects responded to parenteral vaccination with an increase in serum anticapsular antibody. The children's preimmunization anti-PRP antibody level (mean = 0.04 microgram/ml) and 3 wk postimmunization level (mean = 19.3 micrograms/ml) were lower than the adults' (preimmunization mean = 1.5 microgram/ml; postimmunization mean = 81.2 micrograms/ml). Eight of 10 children and seven of nine adults also developed a rise in antibody in nasal secretions. The children's mean nasal preimmunization level was 0.74 microgram/mg IgA and mean postimmunization level was 5.0 micrograms/mg IgA. The adults' mean nasal preimmunization level was 0.98 microgram/mg IgA and mean postimmunization level was 3.0 micrograms/mg IgA. Salivary antibody responses generally followed the pattern of nasal antibody responses. These data suggest that parenteral administration with the Hib capsular polysaccharide can produce a mucosal antibody response. Furthermore, although serum antibody responses to PRP vaccination are greater in adults than in children, mucosal antibody responses are comparable.

Treatment of Staphylococcus aureus infections in children in office practice

One hundred five Staphylococcus aureus infections occurring in 79 children who were seen in a private office practice were evaluated for response to antibiotic therapy. The value of in vitro disk susceptibility testing in directing antibiotic selection in treatment failures was also examined. Of the total episodes studied, the types of infection studied included vesicular pyoderma (48%), secondary pyoderma (13%), bullous pyoderma (5%), furunculosis (14%), carbunculosis (12%), cellulitis (3%), suppurative otitis media (4%), and paronychia (2%). Comparative treatment efficacy was obtained with perioral erythromycin estolate and erythromycin ethylsuccinate, cefaclor and cephalexin, and clindamycin hydrochloride and dicloxacillin sodium. Penicillin V potassium, ampicillin, and topical bacitracin were generally ineffective. In 23 patients, 27/105 infections were initial treatment failures. Antibiotic disk susceptibility testing predicted these clinical failures and/or the antibiotic that would produce a clinical response in 21 of these 23 patients, suggesting that this office procedure can be of considerable value.

Do pili play a role in pathogenicity of Haemophilus influenzae type B?

Surface components of Haemophilus influenzae type b (Hib) responsible for mucosal adherence were identified through assay of in-vitro attachment to human buccal epithelial cells (EC). Among many Hib strains from cerebrospinal fluid, blood, or the nasopharynx (NP), two isolates from NP were found to be exceptionally adherent. Adherence correlated with agglutination of human red blood cells (RBC). The adherent strains displayed pili, not previously described for Hib or other encapsulated H. influenzae. Moreover, highly adherent, piliated subpopulations of bacteria could be selected from any strain, but were lost upon subculture. Thus, the potential to express pili may be general for Hib and may aid the NP colonisation which precedes systemic invasion by this organism. Piliation was correlated with the amount of an outer membrane protein with a molecular weight of about 20,000 daltons, which had proved to be immunogenic in an 8-month-old child.

Relationship between naturally occurring human mucosal and serum antibody to the capsular polysaccharide of Haemophilus influenzae type b

The prevalence of natural mucosal antibody to the capsular polysaccharide (polyribosylribitolphosphate [PRP]) of Haemophilus influenzae type b in adults at multiple secretory sites and the relationship between natural serum and mucosal antibodies with respect to their amount and fine binding specificity were examined. All of 16 lactating women had antibody to PRP in serum and mammary samples; 11 of 14 studied had nasal antibody and 12 of 14 had salivary antibody. The amount of serum antibody to PRP in an individual positively correlated with the amount of mucosal antibody at each of the three secretory sites examined, and the antibody amount between certain secretions were also positively correlated. Antibody to PRP that is cross-reactive with Escherichia coli K100 or Streptococcus pneumoniae type 6 capsular polysaccharides was detected in the secretions of seven and one subjects, respectively, but the amount was not correlated with serum cross-reactive antibody.

Polymicrobial osteomyelitis: report of three cases and review of the literature

Five percent of patients with acute osteomyelitis and 30%-60% of patients with chronic osteomyelitis have polymicrobial infections. Three illustrative cases and a review of the literature involving 104 patients are presented in this report. There were 2.4 isolates per child among the 31 pediatric cases ad 3.9 isolates per adult among the 71 adult cases reviewed. Staphylococcus aureus was the single most common isolate involved in polymicrobial disease in both adults and children. In adults, one-third of the aerobic isolates were gram-negative bacterial species; some enterococci were also involved. Of the isolates from adults, 46% were anaerobic. The number of isolates per case was similar for the acute (3.2) and chronic (3.1) forms of infection. Polymicrobial osteomyelitis resulted most frequently from spread of infection from a contiguous focus (59% of cases) or occurred in the patient with peripheral vascular insufficiency or neuropathy (17% of cases); however, the hematogenous route can produce polymicrobial disease (13% of cases). Bones mot often involved are those of the skull, face, and feet. Standard antibiotic therapy for monomicrobial osteomyelitis with semisynthetic penicillins or cephalosporins may lead to failures of treatment in polymicrobial disease.

Epidemiologic studies of Streptococcus pneumoniae in infants: antibody response to nasopharyngeal carriage of types 3, 19, and 23

The relationship between nasopharyngeal carriage of Streptococcus pneumoniae types 3, 19, and 23 and the development of homotypic serum antibody was examined in 17 infants followed prospectively from birth. Serially drawn sera from these children and single serum samples from 18 normal adolescents were assayed for opsonizing antibody using reduction of nitroblue tetrazolium to measure phagocytosis of killed whole pneumococci. Selected sera were also tested for quantitative antibody level by a radioimmunoassay, which correlated quite well with the nitroblue tetrazolium assay. All but one of the adolescents had antibody to type 19, and all 18 had antibody to type 23. None of the 12 infants tested for antibody to type 19 pneumococci showed evidence of an antibody response. Two of 10 infants responded to type 23 pneumococci, as did two of three infants tested to type 3 pneumococci.

A mucosal antibody response following systemic Haemophilus influenzae type B infection in children

The possibility that mucosal antibody is produced as a host response to Haemophilus influenzae type b (Hib) infection was examined in this study. 17 of 18 prospectively evaluated children ranging in age from 2 mo to 7 yr developed a detectable level of anticapsular antibody in their nasopharyngeal secretions after systemic Hib infection. The mean concentration of nasal anti-capsular antibody of the 18 children was 554 ng/mg IgA (SD = 35-8,863) during the acute phase of illness and declined to 224 ng/mg IgA (SD = 19-2,688) in convalescence. Some children had mucosal antibody detectable at least 10 mo after infection. The mucosal antibody levels were not affected by the length of illness before diagnosis, type of disease, age of the patient, sex, or presence of detectable capsular antigen or viable bacteria in the nasopharynx. The mucosal antibody was predominantly of the IgA class and occurred independent of the serum antibody. Six of the children aged less than 1 yr who did not produce and/or sustain a serum antibody level correlated with protection demonstrated a persistent mucosal antibody response. These findings suggest that the mucosal immune system may have the ability to respond at an earlier age than the serum immune system and lead us to postulate that protective secretory antibodies to prevent systemic Hib disease may be inducible in young infants in spite of the poor serum antibody response occurring at this age.

Breast milk antibody to the capsular polysaccharide of Haemophilus influenzae type b

Breast milk has a high concentration of secretory immunoglobulin and potentially could serve as a source of passive antibody protection of infants against systemic invasion by Haemophilus influenzae type b. Specific antibody to the capsular polysaccharide of this organism was detected in the colostrum and all subsequent milk samples in 11 of 12 women with a radioactive antigen binding assay. The geometric mean concentrations of antibody were 1.99 microgram/ml in colostrum and 0.18 microgram/ml in breast milk at six weeks and after four and one-half to six months of lactation. Antibody levels in colostrum correlated positively with those in subsequent milk samples; levels after six weeks of lactation correlated highly with those present after four and one-half to six months of lactation. IgA was the predominant immunoglobulin class of anticapsular antibody in the colostrum and milk samples as detected by an enzyme-linked immunosorbent assay.

Diphtheria-pertussis-tetanus vaccine: reactogenicity of commercial products

Parents from four practices were surveyed to ascertain reactions of children to diphtheria-pertussis-tetanus (DPT) vaccine in the 48 hours after immunization. Vaccines were administered according to current recommendations. Responses were scored in three categories: temperature, behavioral changes, and local reactions. Questionnaires were returned by 1,232 (84.9%) patients. Only 7.0% reported no reaction, while 336 (27.3%) reported mild, 722 (58.6%) moderate, and 88 (7.1%) severe reactions. Over 50% experienced temperatures of at least 100 F, and 80% noted behavioral changes; 72.2% had local reactions. No encephalitis, seizures, or hospitalizations were reported. Reactogenicity was similar for the five immunizations of the recommended series and the two manufacturers evaluated. Reported reactions in the control group were significantly lower than in the study group. These reaction rates underline the need to reevaluate present DPT vaccines.

Recurrent Reye's syndrome

The clinical diagnosis of recurrent Reye's syndrome can be made only after a systemic exclusion of other diagnostic possibilities. We report such a case, providing guidelines for a complete clinical and biochenical evaluation of this entity. If a comprehensive study of patients experiencing recurrent Reye's syndrome is to be made, each patient must be subjected to thorough examination.

Cyclic adenosine monophosphate stimulation of axonal elongation

Elevated concentrations of adenosine 3',5'-monophosphate induce a variety of cell movements. The role of adenosine 3',5'-monophosphate in promoting those movements associated with growth prompted our study of in vitro microtubule-dependent axonal elongation. Ganglia treated with adenosine 5'-monophosphate show no enhancement over controls; treatment with adenosine 3', 5'monophosphate or its dibutyryl derivative significantly enhances elongation, as measured by increases in both axonal numbers and length. Our study suggests that adenosine 3',5'-monophosphate promotes elongation by stimulation of microtubule assembly.

Separation of lymphocytes and macrophages from suspensions of guinea pig peritonitis exudate cells using programmed gradient sedimentation

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