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.

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.

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.

Multicenter controlled trial comparing ceftibuten with amoxicillin/clavulanate in the empiric treatment of acute otitis media. Members of the Ceftibuten Otitis Media United States Study Group

The efficacy and safety of ceftibuten (9 mg/kg daily for 10 days) were compared with those of amoxicillin/clavulanate (Augmentin 40 mg/kg/day given every 8 hours for 10 days) in the empiric treatment of acute otitis media in children. This was a multicenter, investigator-blinded study with 1:1 randomization. Overall clinical response and signs and symptoms of otitis were collected prospectively pretreatment, 3 to 5 days during treatment, 1 to 3 days post-treatment and at 2- to 4-week follow-up. In addition to spontaneous reports of other adverse events, gastrointestinal adverse events were prospectively elicited at each visit. Two hundred ninety-six patients (146 ceftibuten and 150 amoxicillin/clavulanate) were treated with at least 1 dose of study medication. Compliance with dosing was assessable with weight of drug consumed in 127 patients in each treatment group. Five percent (6 of 127) of ceftibuten patients and 11% (14 of 127) of amoxicillin/clavulanate patients received < 80% of prescribed drug (P = 0.10) and were therefore not valid. Two hundred twenty-two patients (121 ceftibuten and 101 amoxicillin/clavulanate) received a minimum of 80% of prescribed medication and were compliant with the protocol. Ceftibuten and amoxicillin/clavulanate groups were comparable both for demographic variables and for baseline signs and symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Ceftibuten vs. penicillin V in group A beta-hemolytic streptococcal pharyngitis. Members of the Ceftibuten Pharyngitis International Study Group

The efficacy and safety of a 10-day course of ceftibuten oral suspension (9 mg/kg once daily) were compared with those of penicillin V (25 mg/kg/day in 3 divided doses) in children 3 to 18 years old treated for symptomatic pharyngitis and scarlet fever caused by group A beta-hemolytic streptococci (Streptococcus pyogenes). The study was prospective, randomized, multicenter and investigator-blinded; patients were randomized in a 2:1 ratio (ceftibuten:penicillin V). Overall clinical success (cure/improvement) at the primary end point of treatment (5 to 7 days posttherapy) was achieved in 97% (285 of 294) of ceftibuten-treated patients vs. 89% (117 of 132) of penicillin V-treated patients (P < 0.01). Elimination of infecting streptococci 5 to 7 days posttherapy was achieved in 91% (267 of 294) of ceftibuten-treated patients vs 80% (105 of 132) of penicillin V-treated patients (P < 0.01). A significant rise in anti-streptolysin O or anti-DNase B was observed in approximately 30% of patients in both treatment groups. No patient developed rheumatic fever or nephritis. Treatment-related adverse events were similar between the two groups; mild vomiting (2%) was most frequently reported. These data suggest that once daily ceftibuten is as safe as and more effective than three times daily penicillin V for the treatment of group A beta-hemolytic streptococcal pharyngitis.

Immunologic response of extremely premature infants to tetanus, Haemophilus influenzae, and polio immunizations

OBJECTIVE

To determine whether extremely premature infants have immunologic responses to tetanus toxoid, Haemophilus influenzae type b polysaccharide and polio vaccines similar to those of full-term infants.

INFANTS AND METHODS

Sixteen extremely premature (< 29 weeks, < 1000 g at birth) infants received separate diphtheria-tetanus-pertussis and H influenzae type b oligosaccharide-CRM197-conjugated (HbOC) vaccines at 2, 4 and 6 months of chronologic age, enhanced potency inactivated polio vaccine at 2 months, and oral polio vaccine at 4 months. Serum was obtained for anti-tetanus toxoid (TT), anti-Haemophilus b polysaccharide (HbPs) and polio neutralizing antibody assays before the 2-month vaccination and 4 to 6 weeks after the 6-month vaccination. Comparison sera were obtained from full-term infants immunized with the same lots of diphtheria-tetanus-pertussis (n = 46) and HbOC (n = 66) vaccines or the same sequence of polio vaccines (n = 10).

RESULTS

Preterm and full-term infants had similar geometric mean titers of anti-TT antibodies, anti-HbPs antibodies, and neutralizing antibodies to polio serotypes 1, 2, and 3 after the completion of the primary series of vaccines. After vaccination, similar proportions of preterm and full-term infants had protective levels of antibody to TT (preterm 100% vs full-term 100% with levels > 0.01 IU/mL), HbPS (82% vs 87%, > 1.0 microgram/mL), and polio serotypes 1 (85% vs 80%, > or = 1:8) and 2 (100% vs 100%, > or = 1:8). Preterm infants were less likely than full-term infants to have protective levels of neutralizing antibody to polio serotype 3 (31% vs 90%, > or = 1:8).

CONCLUSIONS

Extremely premature infants have adequate antibody responses to tetanus and HbOC antigens but may have diminished responsiveness to serotype 3 polio vaccine.

Persistent acute otitis media: II. Antimicrobial treatment

In this three-year prospective study, 137 children with acute otitis media (AOM) that had not responded after one or two empiric antimicrobial treatment courses (termed persistent AOM) underwent tympanocentesis to determine additional antimicrobial therapy based on in vitro susceptibility testing of the bacterial isolate(s). One hundred eleven children with AOM not previously treated are described for comparison. In the persistent AOM group middle ear aspirates grew Streptococcus pneumoniae (24%), Haemophilus influenzae (7%), Brahamella catarrhalis (7%), Streptococcus pyogenes (6%), Staphylococcus aureus (5%), two pathogens (3%) or no bacterial growth (49%); pathogens in previously untreated AOM were similar but fewer patients (30%) had no bacterial growth. After tympanocentesis additional antimicrobial therapy for persistent AOM patients utilizing drugs shown to be effective in vitro against the isolated pathogen failed to produce clinical resolution of infection in 27 (28%) of ears. Differing clinical efficacy was observed with various antimicrobials: amoxicillin (57% failure); trimethoprim/sulfamethoxazole (75% failure); cefaclor (37% failure); cefixime (23% failure); amoxicillin/clavulanate (12% failure); and cefuroxime axetil (13% failure). Presumptive clinical cure for previously untreated AOM patients was similar to that for untreated AOM except for fewer amoxicillin failures (30%). We conclude that clinical failure in persistent AOM occurs (1) even when no pathogen is isolated from tympanocentesis (50% of patients) and (2) despite demonstrated in vitro activity against culture-proved pathogens.

Group A streptococcal tonsillopharyngitis: cost-effective diagnosis and treatment

Most patients who seek medical attention for sore throat are concerned about streptococcal tonsillopharyngitis, but fewer than 10% of adults and 30% of children actually have a streptococcal infection. Group A beta-hemolytic streptococci (GAS) are most often responsible for bacterial tonsillopharyngitis, although Neisseria gonorrhea, Arcanobacterium haemolyticum (formerly Corynebacterium haemolyticum), Chlamydia pneumoniae (TWAR agent), and Mycoplasma pneumoniae have also been suggested as possible, infrequent, sporadic pathogens. Viruses or idiopathic causes account for the remainder of sore throat complaints. Reliance on clinical impression to diagnose GAS tonsillopharyngitis is problematic; an overestimation of 80% to 95% by experienced clinicians typically occurs for adult patients. Overtreatment promotes bacterial resistance, disturbs natural microbial ecology, and may produce unnecessary side effects. Existing data suggest that rapid GAS antigen testing as an aid to clinical diagnosis can be very useful. When used appropriately, it is sensitive (79% to 88%) in detecting GAS-infected patients and is specific (90% to 96%) and cost-effective. Penicillin has been the treatment of choice for GAS tonsillopharyngitis since the 1950s; 10 days of treatment are necessary for bacterial eradication. A single IM injection of benzathine penicillin is effective and obviates compliance issues. Until the early 1970s, the bacteriologic failure rate for the treatment of GAS tonsillopharyngitis ranged from 2% to 10% and was attributed to chronic GAS carriers. Since the late 1970s, the penicillin failure rate has frequently exceeded 20% in published reports. Explanations for recurrent GAS tonsillopharyngitis include poor patient compliance; reacquisition from a family member or peer, copathogenic colonization by Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis, anaerobes that inactivate penicillin with beta-lactamase, or all these organisms; suppression of natural immune response by too-early administration of antibiotics; GAS tolerance to penicillin; antibiotic eradication of normal pharyngeal flora that normally act as natural host defenses; and establishment of a true carrier state. When therapy fails, milder symptoms may occur during the relapse. Several antimicrobials have demonstrated superior efficacy compared with penicillin in eradicating GAS and are administered less frequently to enhance patient compliance. In previously untreated GAS throat infections, cephalosporins produce a 5% to 22% higher bacteriologic cure rate; after a penicillin treatment failure, these differences are greater. Amoxicillin/clavulanate and the extended-spectrum macrolides clarithromycin and azithromycin may also produce enhanced bacteriologic eradication in comparison to penicillin.(ABSTRACT TRUNCATED AT 400 WORDS)

Persistent acute otitis media: I. Causative pathogens

In this prospective study tympanocentesis was performed to determine the pathogens isolated from middle ear fluid of 200 ears in 137 children with acute otitis media (AOM) which had not responded after one or two empiric antimicrobial treatment courses (termed persistent AOM). For comparison tympanocentesis from 154 ears in 111 children with AOM not previously treated are described. Patients were enrolled from October, 1989, until September, 1992. In the persistent AOM group amoxicillin and trimethoprim/sulfamethoxazole were the most frequently used antimicrobials before tympanocentesis. Middle ear aspirates produced no pathogenic bacterial growth in 49% of persistent AOM patients, Streptococcus pneumoniae in 24%, Haemophilus influenzae in 7%, Branhamella catarrhalis in 7%, Streptococcus pyogenes in 6%, Staphylococcus aureus in 5% and two pathogens in 3%. Two (18%) of 11 S. pneumoniae isolates tested were penicillin-resistant; 1 was intermediate and 1 was highly resistant. Ten (83%) of 12 H. influenzae and all of 11 B. catarrhalis AOM isolates produced beta-lactamase. In comparison previously untreated AOM patients produced no bacterial growth from tympanocentesis in 30%, S. pneumoniae in 36% (8% penicillin-resistant), H. influenaze in 13% (44% beta-lactamase-producing) and B. catarrhalis in 11% (85% beta-lactamase producing). AOM which is persistent after initial empiric antimicrobial therapy may be caused by middle ear inflammation after bacteria are killed or involve penicillin-resistant S. pneumoniae, beta-lactamase-producing H. influenzae or B. catarrhalis more commonly than occurs in AOM which has not been recently treated.

Effective short-course treatment of acute group A beta-hemolytic streptococcal tonsillopharyngitis. Ten days of penicillin V vs 5 days or 10 days of cefpodoxime therapy in children

OBJECTIVE

To compare bacteriologic and clinical efficacy and safety of 10 vs 5 days of cefpodoxime proxetil vs 10 days of penicillin V potassium for the treatment of acute group A beta-hemolytic streptococcal tonsillopharyngitis in children.

DESIGN

Prospective, randomized, observer-blind, multicenter study.

PATIENTS/INTERVENTIONS

Four hundred eighty-four children (age range, 2 to 17 years) with signs and symptoms of acute tonsillopharyngitis were enrolled; 377 had a positive throat culture for group A beta-hemolytic streptococci and were fully evaluable. One hundred twenty-one patients received cefpodoxime once a day for 10 days, 126 received cefpodoxime twice a day for 5 days, and 130 received penicillin V three times a day for 10 days.

RESULTS

Cefpodoxime for 10 days vs cefpodoxime for 5 days vs penicillin V for 10 days produced bacteriologic eradication at the end of therapy in 95%, 90%, and 78% of the patients, respectively. The 10- and 5-day cefpodoxime treatment regimens were more efficacious than penicillin V (P = .003 and P = .02, respectively). The cumulative bacteriologic failure rate among assessable patients by the 32- to 38-day posttreatment visit was 20 (17%) of 121 patients who were treated with cefpodoxime for 10 days, 24 (19%) of 125 patients who were treated with cefpodoxime for 5 days, and 45 (35%) of 130 patients who were treated with penicillin V for 10 days (P = .001 and P = .005, respectively). Clinical cure or improvement was observed at the end of therapy in 96%, 94%, and 91% of the patients, respectively (P = not significant). Adverse events were infrequent and similar in all three treatment groups, with minor gastrointestinal side effects predominating.

CONCLUSIONS

Five days of treatment with cefpodoxime is as efficacious in bacteriologic eradication and clinical response (cure plus improvement) as 10 days of cefpodoxime therapy, and both cefpodoxime regimens produced superior bacteriologic efficacy compared with a 10-day regimen of penicillin V in the treatment of group A beta-hemolytic streptococcal tonsillopharyngitis in children.

Comparison of a three-component acellular pertussis vaccine with a whole-cell pertussis vaccine in 4- through 6-year-old children. Elmwood Pediatric Associates, Pennridge Pediatric Associates

OBJECTIVE

To compare the safety and immunogenicity of a three-component acellular pertussis (DTaP) vaccine containing pertussis toxin (PT), filamentous hemagglutinin (FHA), and pertactin with whole-cell pertussis (DTwP) vaccine in 4- through 6-year-old children.

PARTICIPANTS

One hundred seventy-two healthy 4- through 6-year-old children previously immunized with the DTwP vaccine at or near 2, 4, 6, and 18 months of age.

INTERVENTIONS

Prevaccination serum samples were obtained on all study participants. One hundred twelve children received 0.5 mL of the DTaP vaccine intramuscularly. Fifty-three children received 0.5 mL of a commercially available DTwP vaccine intramuscularly. Approximately 30 days following vaccination, additional serum samples were obtained.

MEASUREMENTS

Parents monitored adverse reactions for 7 days following immunization. Significantly fewer children in the DTaP group reported temperatures of greater than 38.1 degrees C and an area of redness of more than 10 mm and moderate-to-severe pain at the injection site.

RESULTS

Antibody responses to PT, FHA, pertactin, and diphtheria and tetanus toxoids were measured by enzyme-linked immunosorbent assay. Among subjects who were seronegative prior to vaccination, response was defined as the detection of antibody levels following vaccination; among children with detectable antibody levels prior to vaccination, in terms of the rise in antibody titers. Data using a twofold and a fourfold rise in antibody titers as criteria to define response were evaluated. Children in the DTaP group had significantly greater increases in geometric mean titers of antibodies against PT, FHA, and pertactin. Over 90% of the DTaP group responded to PT, FHA, and pertactin according to the criteria of both the twofold and the fourfold rise in antibody titers. Significantly fewer of the DTwP group responded to PT, FHA, and pertactin with at least a fourfold rise in antibody titers. When analyzing subjects with at least a twofold increase in antibody titers, a statistically significant difference remained in regard to anti-FHA antibodies. All study subjects had protective antibody titers against diphtheria and tetanus toxoids following vaccination. The geometric mean titer of antibodies against tetanus was significantly greater in the DTwP group than in the DTaP group.

CONCLUSION

The three-component DTaP vaccine administered as a booster immunization in 4-through 6-year-old children produced less fever and less redness and pain at the injection site than the DTwP vaccine and was as immunogenic as the DTaP vaccine.

Comparison of a three-component acellular pertussis vaccine with whole cell pertussis vaccine in two-month-old children

An acellular pertussis vaccine (DTaP) containing pertussis toxoid, filamentous hemagglutinin and the 69-kDa outer membrane protein (pertactin) was compared with United States-licensed whole cell pertussis vaccine (DTwP) as a three dose sequence at 2, 4 and 6 months of age. Eighty infants were enrolled; 62 received DTaP and 18 received DTwP. Sixty-two infants had preimmunization and 1 month postimmunization sera available for pertussis antibodies. No infant experienced a serious adverse reaction. Significantly fewer infants in the DTaP group experienced irritability (P < 0.001) and moderate to severe injection site pain and redness (P < 0.001, and P = 0.03, respectively). The DTaP group also had significantly greater increases in geometric mean titers of antibodies against filamentous hemagglutinin (P < 0.001) and pertactin (P = 0.006). This three-component DTaP vaccine induced an antibody response to pertussis toxin, filamentous hemagglutinin and pertactin but caused fewer adverse reactions than DTwP when administered as a primary series of immunization to 2-month-old infants.

Acellular and whole-cell pertussis vaccines as booster doses: a multicenter study

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 pertussis 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), pertactin, and/or agglutinogens.

RESULTS

Two hundred 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 contained FHA. Postbooster PT antibody levels were similar among the AC groups, regardless of the amount of PT administered (between 3.5 and 25 micrograms per 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 acellular 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 Infectious Diseases-sponsored study in infants.

Compliance with antibiotic therapy: a comparison of deuterium oxide tracer, urine bioassay, bottle weights, and parental reports

OBJECTIVE

To compare three traditional measures of compliance with antibiotic therapy (parent report diary, preregimen and postregimen bottle-weight difference, and urine bioassay for antibiotic activity), with a deuterium oxide tracer measure of compliance.

METHODS

Clinical trial in which all four compliance measures were used for subjects participating in a comparison of the efficacy of azithromycin and penicillin in treating group A beta-hemolytic streptococcal infection. Subjects were 41 children, aged 3 to 15 years (average age, 7.9 years), in a suburban pediatric private practice, who had positive rapid streptococcal antigen test results.

RESULTS

Of the 41 subjects, 20 children were randomly assigned to receive azithromycin and 21 to receive penicillin. Compliance was uniformly high by all four measures. Parent diaries indicated that all doses were administered. Urine bioassays were obtained for 40 subjects, and all showed antibiotic activity. Differences in bottle weights were obtained for 27 subjects and showed that 142% of the prescribed medication was missing from the bottles at the end of the regimen. The deuterium oxide measure was obtained for 40 subjects and showed that 107% of the prescribed azithromycin and 92% of the prescribed penicillin were ingested. The correlation coefficient between measured and expected deuterium enrichment was 0.89. There was no significant correlation between the bottle-weight measure and the deuterium oxide tracer.

CONCLUSIONS

The bottle-weight measure overestimates compliance; the deuterium oxide tracer is feasible for use in an office setting and produces a high correlation between the expected urinary enrichment and the measured enrichment. Increased use of this quantitative and direct measure would improve the accuracy of compliance measurement in trials of pediatric liquid medications.

A comparative evaluation of the safety and immunogenicity of a single dose of unbuffered oral rhesus rotavirus serotype 3, rhesus/human reassortant serotypes 1, 2 and 4 and combined (tetravalent) vaccines in healthy infants

To assess safety and immunogenicity, 213 healthy infants aged 6 weeks to 4 months were randomized to receive a single dose of placebo, a 10(4) or 10(5) p.f.u. dose of rhesus rotavirus (RRV) serotype 3, human-RRV reassortant (VP-7 serotypes 1, 2 or 4) or a 10(4) or 10(5) p.f.u. dose of tetravalent rotavirus vaccine (containing equal parts of serotype 1, 2, 3 and 4 strains). The infants were fed ad libitum before and after vaccination; no buffer was used. For 7 days after vaccination, potential vaccine side effects were monitored, and no significant differences were noted for any symptom evaluated among the single serotype, tetravalent or placebo groups. Sera, obtained before and 28 days after vaccination, were measured for antibody to rotavirus by IgG, IgA and IgM enzyme-linked immunosorbent assay in all subjects, and by neutralizing antibody to the individual serotypes by plaque reduction in placebo and tetravalent vaccinees. The serological response rates for serotypes 1, 2, 3, 4 and the tetravalent vaccine were 25, 12, 19, 11 and 22%, respectively, at 10(4) p.f.u.; 47, 50, 35, 29 and 61%, respectively, at 10(5) p.f.u.; and 37% for placebo. The tetravalent vaccine was more immunogenic at 10(5) than at 10(4) p.f.u. (p = 0.04). Grouped together, the vaccines at 10(5) p.f.u. (single serotype and tetravalent) were more immunogenic than the vaccines at 10(4) p.f.u. (38 of 85 versus 17 of 94 seroresponders; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Safety and immunogenicity of an acellular pertussis vaccine booster in 15- to 20-month-old children previously immunized with acellular or whole-cell pertussis vaccine as infants

The objective of this study was to evaluate reactogenicity and immunogenicity of the recently US-licensed Connaught/BIKEN (C/B) acellular DTP (ADTP) vaccine as a booster for children aged 15 to 20 months after they had received either the C/B ADTP or the US-licensed Connaught whole-cell DTP (WDTP) vaccine as infants. After infants had received either three doses of C/B ADTP (n = 109) or three doses of WDTP vaccine (n = 30) at 2, 4, and 6 months of age according to a 3:1, randomized, prospective design, they all received booster doses at 15 to 20 months of age with C/B ADTP. Fever > 101 degrees F (38.3 degrees C), irritability, injection site redness > or = 1 inch, injection site swelling, and injection site pain, among other reactions, were monitored for 14 days after vaccination. IgG antibody to pertussis toxin (PT) and filamentous hemagglutinin were analyzed by enzyme-linked immunosorbent assay and neutralizing antibody to PT was measured by Chinese hamster ovary (CHO) cell assay. No significant differences were observed between the WDTP- and ADTP-primed infants following their ADTP booster for any of the monitored reactions within 72 hours of vaccine administration or in the 4 to 14 days after vaccination. Prior to the ADTP booster, antibody levels were higher in children who had received ADTP compared with those who had received WDTP vaccine as infants for PT antibody as measured by enzyme-linked immunosorbent assay and CHO cell assay. Higher levels of IgG antibody following the ADTP booster were observed to filamentous hemagglutinin and to PT in ADTP-primed compared with WDTP-primed children.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of a diphtheria and tetanus toxoids and bicomponent acellular pertussis vaccine with diphtheria and tetanus toxoids and whole-cell pertussis vaccine in infants

OBJECTIVE

To compare the reactogenicity and immunogenicity of a diphtheria and tetanus toxoids and two-component acellular pertussis (ADTP) vaccine with a US-licensed whole-cell (WDTP) vaccine.

SETTING

General pediatric practice in suburban Rochester, NY.

DESIGN

Prospective, double-blind, randomized study.

PARTICIPANTS

One hundred ten infants were studied; 88 (80%) received ADTP and 22 (20%) received WDTP at ages 2, 4, and 6 months.

INTERVENTION

Vaccination.

MEASUREMENTS/MAIN RESULTS

Temperature of 38.3 degrees C or higher (P = .03) and moderate or severe injection-site pain (P = .02) occurred less frequently in infants receiving ADTP than those receiving WDTP for the combined three doses. Following the third dose, ADTP vaccination produced higher antibody responses than WDTP to pertussis toxin (geometric mean enzyme-linked immunosorbent assay IgG was 52.2 vs 12.5; P < .001) and to filamentous hemagglutinin (geometric mean IgG was 182.8 vs 3.5; P < .001). No interference in the diphtheria or tetanus antibody responses was observed in recipients of the ADTP vaccine.

CONCLUSIONS

This two-component ADTP vaccine, when given as a primary infant series, produces fewer adverse effects and greater immunogenicity to the two pertussis components that it contains than US-licensed WDTP vaccine.

Efficacy of cefuroxime axetil suspension compared with that of penicillin V suspension in children with group A streptococcal pharyngitis

The bacteriological and clinical efficacies of cefuroxime axetil suspension (20 mg/kg of body weight per day in two divided doses) were compared with those of penicillin V suspension (50 mg/kg/day in three divided doses) in a multicenter, randomized, evaluator-blinded study. Children aged 2 to 13 years with clinical signs and symptoms of acute pharyngitis and a positive throat culture for group A beta-hemolytic streptococci (GABHS) were eligible. Patients were assessed and samples from the throat for culture were obtained at the time of diagnosis, 3 to 7 days after the initiation of treatment, and 4 to 8 days and 19 to 25 days after the completion of 10 days of therapy. Of the 385 evaluable patients, GABHS were eradicated from 244 of 259 (94.2%) cefuroxime-treated patients and 106 of 126 (84.1%) penicillin-treated patients (P = 0.001). Complete resolution of the signs and symptoms present at the time of diagnosis was achieved in 238 of 259 (91.9%) cefuroxime-treated patients and 102 of 126 (81.0%) penicillin-treated patients (P = 0.001). Potential drug-related adverse events were reported in 7.0 and 3.2% of the cefuroxime- and penicillin-treated patients, respectively (P = 0.078). In the present study, cefuroxime axetil suspension given twice daily resulted in significantly greater bacteriological and clinical efficacies than those of penicillin V suspension given three times daily to pediatric patients with acute pharyngitis and a positive throat culture for GABHS.

Asymptomatic infections due to wild-type rotavirus may prime for a heterotypic response to vaccination with rhesus rotavirus

Variable homotypic and heterotypic protection has been observed following oral vaccination with rhesus rotavirus vaccine. Natural asymptomatic infections may enhance the efficacy of rhesus rotavirus vaccine. Asymptomatic seroconversion before and during the epidemic rotavirus season in Rochester, New York, was examined in a trial of 190 2- to 5-month-old infants receiving rotavirus and placebo vaccines. Six (37.5%) of 16 placebo recipients seroconverted; four of the six did so 2 to 8 months before the Rochester rotavirus season. Among the recipients of rotavirus vaccine, eight seroconverted before the rotavirus season as a consequence of asymptomatic infection. Four of the eight had not seroconverted after rotavirus vaccination, and four seroconverted from asymptomatic infection as well as from vaccination. Twelve rotavirus vaccinees had an asymptomatic seroconversion concurrent with the epidemic rotavirus season in Rochester: eight seroconverted following apparent vaccine failure, and four seroconverted following an apparent vaccine take. Six vaccinated infants with asymptomatic seroconversion during the rotavirus season had significant rises in the level of IgA antibody determined by ELISA, thereby suggesting preferential stimulation of memory cells of IgA. The possibility that variable heterotypic protection following oral rotavirus vaccination may be due to enhanced immunogenicity as a consequence of prior or concurrent infection with circulating wild-type rotaviruses appears to be supported by the findings of this report.

Microbiologic and clinical aspects of a trial of once daily cefixime compared with twice daily cefaclor for treatment of acute otitis media in infants and children

In this randomized, investigator-blinded multicenter study, tympanocentesis for acute otitis media with effusion in 137 ears from 108 children, 6 months to 12 years of age, revealed 84 definite pathogens and 32 potential pathogens. Twenty-nine aspirates from 23 subjects were sterile. Of the 116 isolates 42 (36%) were Streptococcus pneumoniae, 24 (21%) were Haemophilus influenzae, 9 (8%) were Moraxella catarrhalis, 9 (8%) were Streptococcus pyogenes and 1 (1%) was Staphylococcus aureus. Twenty-two (19%) definite pathogens produced beta-lactamase. Patients were randomized to cefixime (8 mg/kg/day daily) or cefaclor (40 mg/kg/day divided into two doses). Efficacy was determined by pneumatic otoscopy and tympanometry at the end of therapy visit on Days 11 to 14 and up to 4 weeks of follow-up. At end of therapy subjects with definite pathogens exhibited a satisfactory clinical outcome in 26 of 36 (72%) ears for cefaclor and 40 of 48 (83%) ears for cefixime recipients (P = 0.12). For ears with beta-lactamase-producing isolates there were no (0 to 12) cefixime failures but 4 of 10 cefaclor failures (P = 0.03). Diarrhea/loose stools were more frequent in cefixime (16 of 58) than cefaclor (4 of 50) recipients. One cefixime subject required discontinuation of drug. Overall efficacy for treatment of acute otitis media with effusion was not different; however, cefixime appeared more effective for infections caused by beta-lactamase-producing organisms.

Explanations and therapies for penicillin failure in streptococcal pharyngitis

A disturbing trend toward penicillin failure has developed in the treatment of streptococcal pharyngitis in some parts of the United States and abroad. A variety of explanations has been proposed to account for these penicillin-treatment failures. With the resurgence of serious complications from streptococcal infection, successful bacteriologic eradication has regained importance. In communities with a high incidence of penicillin failures, alternative antimicrobials should be considered. Cephalosporins, amoxicillin/clavulanate, and the extended-spectrum macrolides represent logical options under such clinical circumstances.

Rotavirus-specific breast milk antibody in two populations and possible correlates of interference with rhesus rotavirus vaccine seroconversion

Milk was collected from 56 New York and 70 Venezuelan mothers participating in Rhesus rotavirus (RRV) pediatric vaccine trials. Plaque reduction neutralization antibody (PRNA) to RRV (VP7:3, VP4:RRV) and human P rotavirus (VP7:3, VP4:P) and epitope-blocking antibody to one RRV VP4 and VP7 epitope were determined. Controlling for postpartum age, more Venezuelan milk samples had detectable RRV and P PRNA, RRV VP4 epitope-blocking antibody (P less than or equal to .001), and higher RRV and P PRNA geometric mean titers (P = .01) than New York samples. Using a logistic regression model, both milk and infants' serum preimmunization RRV PRNA titers had a negative effect on seroconversion (P = .008 and .02, respectively). Only 25% (2/8) infants fed milk containing greater than or equal to 1:160 RRV PRNA seroconverted compared with 83% (5/6) fed milk containing less than 1:160 RRV PRNA (P = .1). Of milk samples containing greater than or equal to 1:160 RRV PRNA, seven (88%) of eight had greater than fourfold neutralizing activity against RRV versus P (P = .035), suggesting that VP4-specific milk antibodies may interfere with RRV seroconversion.

Clinical reactions and immunogenicity of the BIKEN acellular diphtheria and tetanus toxoids and pertussis vaccine in 4- through 6-year-old US children

OBJECTIVE--To compare the immunogenicity and reactogenicity of a two-component acellular pertussis vaccine with a whole-cell diphtheria and tetanus toxoids and pertussis vaccine (W-DTP) when administered as a booster to children 4 through 6 years of age. DESIGN--This was a randomized, double-blind study. SETTING--Children in this study were from three general pediatric practices (two were private, one was university-affiliated). PARTICIPANTS--Three hundred and sixteen 4- through 6-year-old children who had received four previous W-DTP immunizations at the recommended times were studied. SELECTION PROCEDURES AND INTERVENTIONS--Children were randomly assigned in a 1:3 ratio to receive either W-DTP or one of three lots of acellular diphtheria and tetanus toxoids and pertussis vaccine (A-DTP). The A-DTPs contained 3.75 micrograms each of lymphocytosis promoting factor and filamentous hemagglutinin protein nitrogen per 0.5 mL and the same concentrations of diphtheria and tetanus toxoids as W-DTP. Serum samples were obtained on the day of immunization and 4 to 6 weeks later. Adverse reactions were recorded by parents at 6, 24, 48, and 72 hours. MEASUREMENTS AND RESULTS--An indirect enzyme-linked immunosorbent assay (ELISA) method determined IgG antibody response to lymphocytosis promoting factor, filamentous hemagglutinin, and tetanus toxoid; a CHO cell assay measured neutralizing antibodies to pertussis toxin; and serum neutralization on VERO cells assayed diphtheria antitoxin. One month after booster doses were administered, the geometric mean antibody levels for A-DTP vs W-DTP were IgG filamentous hemagglutinin, 362 vs 104 ELISA U/mL; IgG lymphocytosis promoting factor, 408 vs 81 ELISA U/mL; CHO cell, 210 vs 107; diphtheria, 21.7 vs 12.1 U/mL; and tetanus, 2.86 vs 2.04 Eq/mL. Following immunization with A-DTP, local and systemic adverse experiences were 30% to 50% and 20% to 30% fewer, respectively, as compared with W-DTP. CONCLUSIONS--The BIKEN A-DTP vaccine used in this study demonstrates enhanced immunogenicity to lymphocytosis promoting factor, filamentous hemagglutinin, and other measured antigens and less reactogenicity compared with licensed W-DTP [corrected].

Acellular pertussis vaccination of 2-month-old infants in the United States

This is the first study in children from the United States that evaluates the immunogenicity of and adverse reactions to the Connaught/Biken two-component acellular pertussis vaccine compared with whole-cell pertussis vaccine when given as a primary immunization series at 2, 4, and 6 months of age. Three hundred eighty infants were studied; 285 received acellular diphtheria-tetanus toxoids-pertussis (DTP (ADTP)) and 95 received whole-cell DTP (WDTP). Following the third dose, ADTP vaccination produced higher antibody responses than WDTP to lymphocytosis-promoting factor (enzyme-linked immunosorbent assay IgG geometric mean titer (GMT) = 131 vs 9 and Chinese hamster ovary cell assay GMT = 273 vs 16) and to filamentous hemagglutinin (IgG GMT = 73 vs 10) (all P less than .0001). Agglutinin responses were higher in WDTP compared with ADTP recipients (GMT = 50 vs 37; P = .02). Local reactions were fewer for all three doses following ADTP vaccination. Fever, irritability, drowsiness, anorexia, vomiting, and unusual crying all occurred less frequently in ADTP compared with WDTP recipients for one or more of the three doses. We conclude that this two-component ADTP vaccine when given as a primary series produces greater immunogenicity and fewer adverse effects than the currently licensed WDTP vaccine.

Streptococcus pyogenes pharyngitis: characterization of strains by multilocus enzyme genotype, M and T protein serotype, and pyrogenic exotoxin gene probing

Multilocus enzyme electrophoresis, serological characterization of M and T proteins, and probing for pyrogenic exotoxin A and C genes were used to investigate the bacteriologic epidemiology of strains of Streptococcus pyogenes recovered primarily from patients with recurrent pharyngitis. A total of 164 strains recovered from individuals living in nine states of the United States was analyzed. Two-thirds of the patients in our sample were infected with the homologous strain following antibiotic therapy and presumably represented treatment failures, whereas the other one-third of the patients were infected with a heterologous strain after therapy and probably represented reinfections. Multilocus enzyme electrophoresis was as efficacious in strain discrimination as serologic typing techniques were and, in addition, successfully characterized all organisms that were serologically nontypeable. Two clones of S. pyogenes responsible for most of the episodes of toxic shock-like syndrome in the United States are geographically widespread, but they vary by locality in the frequency of their occurrence. Compared with a sample of strains cultured from patients whose pharyngeal infections were eliminated by antimicrobial therapy, these two clones were statistically overrepresented among organisms that cause recurrent pharyngitis.

Culture and antigen detection tests for streptococcal tonsillopharyngitis

A throat culture is necessary for accurate diagnosis of group A beta-hemolytic streptococcal tonsillopharyngitis. The use of penicillin therapy in every patient with sore throat results in overtreatment of 85 percent of children and 95 percent of adults presenting to family physicians with the complaint of sore throat. Indiscriminate use of penicillin also increases the risk of drug side effects and subjects some patients to unnecessary alterations of microbial ecology. The signs and symptoms of group A beta-hemolytic streptococcal tonsillopharyngitis are nonspecific, and reliable clinical diagnosis is difficult. Throat culture is cost-effective and, if properly obtained and processed, more than 95 percent accurate. Antigen detection tests (rapid strep tests) are a viable laboratory alternative to throat cultures if these tests are properly performed and if negative test results are confirmed with traditional throat culture.

A comparison of cephalosporins and penicillins in the treatment of group A beta-hemolytic streptococcal pharyngitis: a meta-analysis supporting the concept of microbial copathogenicity

Although penicillin has been the antibiotic of choice for therapy of Group A beta-hemolytic streptococcal pharyngitis for more than four decades, reports of bacteriologic and clinical treatment failures with penicillin have increased in recent years. We conducted a meta-analysis of 19 studies to examine whether oral cephalosporins were associated with lower failure rates than oral penicillin in the treatment of Group A beta-hemolytic streptococcal pharyngitis. The overall bacteriologic cure rate for penicillin was 84% (95% confidence interval (CI), 82%, 86%) compared with 92% (95% CI, 91%, 94%) among patients treated with cephalosporins (P less than 0.0001). The overall clinical cure rate in the penicillin groups was 89% (95% CI, 87%, 91%) compared with 95% (95% CI, 94%, 96%) in the cephalosporin group (P less than 0.001). There was no significant difference between the cephalosporins and the penicillins with respect to adverse events. There may be clinical circumstances in which treatment of Group A beta-hemolytic streptococcal pharyngitis with cephalosporins is indicated.

Controversies in the treatment of streptococcal pharyngitis

An increasing number of cases of sore throat caused by group A beta-hemolytic streptococci occur with concomitant colonization by organisms that may "protect" the streptococci through beta-lactamase inactivation of penicillin at the site of infection. The failure of penicillin to eradicate many of these bacteria, which include Staphylococcus aureus, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and a multitude of pharyngeal anaerobes, may help to explain why penicillin is sometimes ineffective for acute and recurrent group A streptococcal infections. Therapeutic alternatives currently include cephalosporins, erythromycin, rifampin combined with penicillin, amoxicillin/clavulanate potassium and others.

Effect of breast-feeding on oral rhesus rotavirus vaccine seroconversion: a metaanalysis

The effect of concomitant breast-feeding on seroconversion following oral administration of rhesus rotavirus vaccine (RRV, serotype 3, strain MMU 18006) at 10(4) pfu was analyzed. Three studies were included, all randomized, double-blind trials involving a single dose of RRV to infants aged 2-5 months. None received concomitant oral polio vaccine. Seroconversion was measured by microneutralization or tube neutralization assay. The results show that 42 (48%) of 88 (95% confidence interval, 37%-58%) breast-fed babies seroconverted compared with 62 (70%) of 88 (95% confidence interval, 61%-80%) bottle-fed babies (chi 2 = 9.35, P less than .005). Thus, there was a significant adverse effect of breast-feeding with respect to RRV vaccine seroconversion.

Effect of dose and a comparison of measures of vaccine take for oral rhesus rotavirus vaccine. The Maryland Clinical Studies Group

Ninety-six healthy infants ages 2 to 5 months received rhesus rotavirus vaccine serotype 3 (RRV) as a single dose of 10(3), 10(4) or 10(5) plaque-forming units (pfu) in this double-blinded, placebo-controlled study. Half of the infants in each dose group were also randomized to receive either 30 ml of infant formula as buffer before vaccination or were vaccinated on an empty stomach. The incidence of fever, increased stool frequency and decreased activity level was consistently higher among infants who received RRV than those who received placebo. There was no consistent increase in incidence of symptoms as the dose of RRV was increased. Possible vaccine-related side effects were increased in older vaccinees and in those with higher pre-vaccination antibody titers. The seroconversion rate and pre to postvaccination antibody rise, evaluated by enzyme-linked immunosorbent assay and by plaque reduction neutralization, correlated well. The 10(5) and 10(4) pfu RRV dose produced significantly higher rates of seroconversion and higher antibody rises than did placebo (P less than 0.001 for 10(5) and P = 0.005 for 10(4]. The 10(3) pfu dose was no more immunogenic than placebo. In the 10(4) pfu dose group 73% of infants receiving formula as a "buffer" seroconverted compared with 36% of those not receiving formula; 63% of infants partially breast-fed or formula-fed seroconverted compared with 17% of those exclusively breast-fed. These differences in seroconversion rate were largely overcome by increasing the RRV dose to 10(5) pfu. Stool (copro IgA) antibody responses were examined; of six infants showing a copro IgA response only one had seroconverted based on enzyme-linked immunosorbent assay or plaque reduction neutralization. RRV was recovered by tissue culture more frequently from the stool in those infants who received RRV 10(5) and 10(4) pfu than among those receiving 10(3) pfu or placebo (P less than 0.001).

Anatomic and audiologic sequelae after tympanostomy tube insertion or prolonged antibiotic therapy for otitis media

In this study the anatomic and hearing sequelae are characterized for 43 children (86 ears) with recurrent acute otitis media and/or persistent otitis media with effusion who had received three or more tympanostomy tube placements and 46 children (92 ears) managed medically with repeated courses of therapeutic and/or or prophylactic antibiotics. In the surgical group 311 tympanostomy tube surgeries had been performed and in the medical group 1334 episodes of acute otitis media and/or 186 episodes of otitis media with effusion occurred. Tympanosclerosis was found in 6.5% of the medical group ears and 52.3% of the surgical group ears. Tympanic atrophy occurred in 4.3% of the medical group ears and 40.7% of the surgical group ears. The duration of the presence of the tympanostomy tube significantly influenced the tympanic membrane. The presence of middle ear fluid at the time of tube insertion, particularly high viscosity ("glue") fluid, correlated with persisting sclerosis (P less than 0.00001) and reduced tympanic membrane mobility (P less than 0.00001) but not tympanic membrane atrophy (P = 0.94) later. Abnormal hearing, defined as a hearing threshold greater than 20 dB occurred in 9.3 to 18.7% of the surgical ears and in 3.7 to 9.0% of the medical ears depending on the hearing frequency tested. Medical management consisting of recurrent use of therapeutic and/or prophylactic antibiotics was associated with infrequent anatomic and audiologic sequelae. Repeated placement of tympanostomy tubes may be associated with the frequent occurrence of both anatomic and audiologic sequelae.

Effect of oligosaccharide chain length, exposed terminal group, and hapten loading on the antibody response of human adults and infants to vaccines consisting of Haemophilus influenzae type b capsular antigen unterminally coupled to the diphtheria protein CRM197

Vaccines consisting of oligosaccharide (OS) derived from Haemophilus influenzae type b capsular polysaccharide and conjugated to carrier proteins had been shown capable of eliciting memory-type capsular polysaccharide of H. influenza type b antibody responses in human infants, but the structural variables governing immunogenicity were not defined. Here a series of conjugates were made with the diphtheria protein CRM197 and with uniterminally coupled OS haptens that varied in chain length, exposed terminal residue, or multiplicity of loading as defined by ribose/protein ratio. Adults were given a single injection, 1-yr-old infants were given a two-injection sequence, and capsular polysaccharide of H. influenzae type b antibody responses were assessed by radioantigen binding. Vaccines C-4r, C-6r, and C-12r, in which ribitol-ended OS of mean length 4, 6, or 12 repeat units were coupled at low hapten loading, were about equally immunogenic (geometric means 2 to 5 micrograms/ml in infants, 5 to 9 micrograms/ml in adults). Vaccine C7p was made with a higher loading of OS having mean length 7 repeat units and having mainly phosphate monoester at the exposed termini Vaccine C-7R was made from a portion of C-7p by enzymatic removal of most of the terminal phosphates. Compared to the C-4r, C-6r, and C-12r series, vaccines C-7p and C-7R induced geometric means about 10-fold higher in adults and 20-fold higher in infants. Thus OS chain length (in the range studied) and exposed terminus are less critical variables in this system than the extent of hapten loading.

Effect of oligosaccharide chain length, exposed terminal group, and hapten loading on the antibody response of human adults and infants to vaccines consisting of Haemophilus influenzae type b capsular antigen unterminally coupled to the diphtheria protein CRM197

Vaccines consisting of oligosaccharide (OS) derived from Haemophilus influenzae type b capsular polysaccharide and conjugated to carrier proteins had been shown capable of eliciting memory-type capsular polysaccharide of H. influenza type b antibody responses in human infants, but the structural variables governing immunogenicity were not defined. Here a series of conjugates were made with the diphtheria protein CRM197 and with uniterminally coupled OS haptens that varied in chain length, exposed terminal residue, or multiplicity of loading as defined by ribose/protein ratio. Adults were given a single injection, 1-yr-old infants were given a two-injection sequence, and capsular polysaccharide of H. influenzae type b antibody responses were assessed by radioantigen binding. Vaccines C-4r, C-6r, and C-12r, in which ribitol-ended OS of mean length 4, 6, or 12 repeat units were coupled at low hapten loading, were about equally immunogenic (geometric means 2 to 5 micrograms/ml in infants, 5 to 9 micrograms/ml in adults). Vaccine C7p was made with a higher loading of OS having mean length 7 repeat units and having mainly phosphate monoester at the exposed termini Vaccine C-7R was made from a portion of C-7p by enzymatic removal of most of the terminal phosphates. Compared to the C-4r, C-6r, and C-12r series, vaccines C-7p and C-7R induced geometric means about 10-fold higher in adults and 20-fold higher in infants. Thus OS chain length (in the range studied) and exposed terminus are less critical variables in this system than the extent of hapten loading.

Haemophilus influenzae b polysaccharide revaccination: a continued role for the unconjugated vaccine

In a study of the issue of revaccination with Haemophilus influenzae b polysaccharide vaccine, 36 children who had been vaccinated with polysaccharide vaccine at age 18 to 20 months were stratified according to their 3-week postvaccination anticapsular antibody concentration determined by radioantigen binding assay, then sequentially assigned to one of three groups so as to have comparable distributions of peak antibody concentrations. These children were revaccinated with polysaccharide vaccine at 24 to 27, 30 to 33, or 36 to 39 months of age. The post-reimmunization geometric mean antibody concentrations in these three groups were 3.1, 3.0 and 7.8 micrograms/ml, respectively, and the percentages rising to greater than 1 microgram/ml were 75, 80 and 93%. The geometric means and antibody response rates were nearly identical to age-matched control groups not previously vaccinated. Thus there was no evidence of priming (memory induction) or of tolerance induction by the early (18 months old) primary vaccination.

Field trial of rhesus rotavirus vaccine in infants

Orally administered rhesus rotavirus vaccine (RRV) was evaluated in a placebo-controlled study in 176 infants (ages 2 to 4 months). Eighty-eight infants received a dose of 10(4) plaque-forming units of the vaccine, and 88 received the placebo. RRV was well-tolerated but mildly reactogenic in the 10 days after vaccination. There were mild febrile reactions (greater than or equal to 38 degrees C rectally) in 40% of the vaccinees and in 16% of the placebo recipients (P = 0.001). More of the vaccinees had loose stools than did the placebo recipients (P less than 0.05). RRV was immunogenic and induced a 4-fold or greater rise in serum neutralizing antibody responses in 67% of the vaccinees; however, breast-fed infants were less likely to develop a seroresponse than infants who were not breast-fed. Despite the good immunogenicity of RRV the overall incidence of rotavirus-associated illnesses was similar between the vaccine and placebo recipients. The failure of RRV in Rochester may be related to the fact that the circulating rotaviruses were predominantly serotype 1 and RRV is a serotype 3 rotavirus. Because the serotypes of rotavirus that predominate may vary from year to year, a polyvalent preparation may be necessary to provide effective vaccination against rotaviruses.

A multicenter, randomized, single-blind evaluation of cefuroxime axetil and phenoxymethyl penicillin in the treatment of streptococcal pharyngitis

Ninety-three children from four pediatric practices, with clinical and bacteriologic evidence of acute Group A beta-hemolytic streptococcal pharyngitis (GABHS) randomly received cefuroxime axetil (60 cases) or phenoxymethyl penicillin (33 cases). Cefuroxime axetil was given twice daily (125 mg). Phenoxymethyl penicillin was given three times daily (250 mg). The treatment groups were similar. Throat cultures were routine 2 to 7 days after the start of therapy and 2 days and 14 days after the end of therapy. The bacterial cure rates were 85 percent (51/60) for cefuroxime axetil, and 88 percent (29/33) for phenoxymethyl penicillin treated patients. Clinical results were comparable in both treatment groups. It was concluded that cefuroxime axetil given twice daily is as effective as phenoxymethyl penicillin given three times daily in producing bacteriologic eradication and clinical symptomatic improvement in children with GABHS.

Adverse and beneficial effects of immediate treatment of Group A beta-hemolytic streptococcal pharyngitis with penicillin

One hundred forty-two children with presumed Group A beta-hemolytic streptococcal (GABHS) pharyngitis were enrolled in a randomized double blind prospective study comparing the consequences of immediate penicillin treatment with treatment delayed for 48 to 56 hours. One hundred fourteen of the enrolled patients were culture-positive. An adverse impact of early antibiotic therapy was noted; the incidence of subsequent infections with GABHS was significantly greater in those treated at the initial office visit with penicillin. In the month following documented evaluation of GABHS, a recurrence occurred 2 times more frequently in those treated with penicillin immediately compared with those for whom treatment was delayed 48 to 56 hours. Late recurrences (beyond 1 month but in the same streptococcal season) occurred 8 times more frequently (P less than 0.035). Delay in penicillin treatment did not increase GABHS intrafamilial spread. Symptoms of both groups were assessed for 2 days following the initiation of treatment. Both placebo-treated and penicillin-treated groups used aspirin or acetaminophen ad libitum. Penicillin was shown to reduce fever and relieve sore throat, dysphagia, headache, abdominal pain, lethargy and anorexia significantly beyond that achieved with aspirin or acetaminophen alone. Penicillin had no effect on culture-negative cases.

Randomized, single-blind evaluation of cefadroxil and phenoxymethyl penicillin in the treatment of streptococcal pharyngitis

A total of 150 children from two pediatric practices with clinical and bacteriologic evidence of acute group A beta-hemolytic streptococcal (GABHS) pharyngitis randomly received cefadroxil monohydrate (75 children) or phenoxymethyl penicillin (75 children). Cefadroxil was given once daily, while penicillin was given three times daily. The treatment groups were similar in age, sex, race, illness severity, and acute GABHS symptomatology. Throat cultures were routine 3 to 5 days after the start of therapy and 2 and 14 days after the end of therapy. The bacterial cure rates were 90% (62 of 69) for cefadroxil-treated patients and 76% (52 of 68) for penicillin-treated patients. This difference was significant (P less than 0.04). The clinical response was satisfactory in 91% of cefadroxil-treated patients and 89% of penicillin-treated patients. We conclude that once-daily cefadroxil is at least as effective as three-times-daily penicillin in producing bacteriologic eradication and clinical symptomatic improvement in children with GABHS pharyngitis.

Acellular pertussis vaccine: immunogenicity and safety of an acellular pertussis vs. a whole cell pertussis vaccine combined with diphtheria and tetanus toxoids as a booster in 18- to 24-month old children

An acellular pertussis vaccine principally containing two purified pertussis antigens, filamentous hemagglutinin and lymphocytosis-promoting factor, combined with diphtheria and tetanus toxoids was compared to conventional diphtheria-tetanus toxoids-whole cell pertussis for adverse effects and serologic responses in a group of 120 children who were from 18 to 24 months of age. Three vaccinations at 2, 4 and 6 months of age with diphtheria-tetanus toxoids-whole cell pertussis had been administered previously. Adverse effects occurred more frequently with the diphtheria-tetanus toxoids-whole cell pertussis than with diphtheria-tetanus toxoids-acellular pertussis vaccine. Fever occurred significantly more often and to a higher degree in the whole cell pertussis vaccine recipients with a peak difference occurring 6 hours after immunization (P = 0.00008). Local swelling, redness, warmth and tenderness at the injection site also occurred significantly more frequently following whole cell pertussis vaccination. No major sequelae were noted in either group. The antibody responses to lymphocytosis-promoting factor were similar for the two vaccines. The diphtheria-tetanus toxoids-acellular pertussis vaccine produced significantly lower pertussis agglutinin titers (P = 0.00001) but significantly higher antibody to filamentous hemagglutinin (P = 0.05) and to diphtheria (P = 0.03). The protective role of antibody to pertussis agglutinins vs. filamentous hemagglutinin and lymphocytosis-promoting factor continues as a central issue in the quest for a new pertussis vaccine. A clinical efficacy trial is needed.