John W. Boslego

Efficacy of a quadrivalent prophylactic human papillomavirus (types 6, 11, 16, and 18) L1 virus-like-particle vaccine against high-grade vulval and vaginal lesions: a combined analysis of three randomised clinical trials

BACKGROUND Vulval and vaginal cancers among younger women are often related to infection with human papillomavirus (HPV). These cancers are preceded by high-grade vulval intraepithelial neoplasia (VIN2-3) and vaginal intraepithelial neoplasia (VaIN2-3). Our aim was to do a combined analysis of three randomised clinical trials to assess the effect of a prophylactic quadrivalent HPV vaccine on the incidence of these diseases. METHODS 18 174 women (16-26 years) were enrolled and randomised to receive either quadrivalent HPV6/11/16/18 L1 virus-like-particle vaccine or placebo at day 1, and months 2 and 6. Individuals underwent detailed anogenital examination at day 1, 1 month after dose three, and at 6-12-month intervals for up to 48 months. Suspect genital lesions were biopsied and read by a panel of pathologists and vaccine HPV type-specific DNA testing was done. The primary endpoint was the combined incidence of VIN2-3 or VaIN2-3 associated with HPV16 or HPV18. Primary efficacy analyses were done in a per-protocol population. FINDINGS The mean follow-up time was 3 years. Among women naive to HPV16 or HPV18 through 1 month after dose three (per-protocol population; vaccine n=7811; placebo n=7785), the vaccine was 100% effective (95% CI 72-100) against VIN2-3 or VaIN2-3 associated with HPV16 or HPV18. In the intention-to-treat population (which included 18 174 women who, at day 1, could have been infected with HPV16 or HPV18), vaccine efficacy against VIN2-3 or VaIN2-3 associated with HPV16 or HPV18 was 71% (37-88). The vaccine was 49% (18-69) effective against all VIN2-3 or VaIN2-3, irrespective of whether or not HPV DNA was detected in the lesion. The most common treatment-related adverse event was injection-site pain. INTERPRETATION Prophylactic administration of quadrivalent HPV vaccine was effective in preventing high-grade vulval and vaginal lesions associated with HPV16 or HPV18 infection in women who were naive to these types before vaccination. With time, such vaccination could result in reduced rates of HPV-related vulval and vaginal cancers.

Efficacy, safety, and immunogenicity of a meningococcal group B (15:P1.3) outer membrane protein vaccine in Iquique, Chile

A meningococcal group B (15:P1.3) outer membrane protein vaccine was tested for efficacy in a randomized, double-blind controlled study in Iquique, Chile. A total of 40 811 volunteers, ages 1-21 years, enrolled in the study. Volunteers received two doses of vaccine six weeks apart by jet injector. Both the experimental vaccine and the control vaccine (Menomune, A, C, Y and W135 meningococcal polysaccharide vaccine) were well tolerated with minor side-effects. Active surveillance for suspected cases of meningococcal disease was conducted for 20 months in Iquique. Eighteen cases of group B meningococcal disease were confirmed during the 20 months. Efficacy was estimated to be 51% (p = 0.11) for all ages combined. In children aged 1-4 no protection was evident, but in volunteers aged 5-21 vaccine efficacy was 70% (p = 0.045). The IgG antibody response by ELISA was characterized by a large booster effect after the second dose, followed by a substantial drop in antibody levels by 6 months. The youngest children had the highest responses. The bactericidal antibody response, on the other hand, was characterized by the lack of a significant booster response, higher responses in the older children, and an increase in the geometric mean titer in the later months of the study in the older children.

Efficacy trial of a parenteral gonococcal pilus vaccine in men

A randomized, placebo-controlled, double-blind efficacy trial of a purified gonococcal pilus vaccine composed of a single pilus type was tested in 3123 men and 127 women volunteers. Either 100 micrograms of vaccine or a placebo was given intradermally on day 1 and day 14. Each group was evenly matched with respect to age, sex, prior history of a sexually transmitted disease, sexual exposure during the study and attrition from the study. None of the women volunteers acquired gonorrhoea during the trial. In the male volunteers, 108 vaccine and 102 placebo recipients acquired gonorrhoea 15 days or later after the initial immunization. Vaccines developed a sustained ELISA antibody response to homologous and heterologous pili, but the latter titres were approximately 40% as high as the homologous pilus antibody rises. There were, however, no increases in inhibition of attachment antibody (IEA) titres. Local antibodies (semen) against homologous and heterologous strains were also elicited (ELISA). The vaccine was safe and did not alter the clinical expression of disease. This gonococcal pilus vaccine composed of a single pilus type failed to protect men against gonococcal urethritis.

Efficacy, Immunogenicity, and Safety of a Pentavalent Human-Bovine (WC3) Reassortant Rotavirus Vaccine at the End of Shelf Life

BACKGROUND. Rotavirus is the leading cause of dehydrating acute gastroenteritis in infants worldwide. Previous studies of a live pentavalent human-bovine reassortant rotavirus vaccine have shown it to be efficacious across a range of potencies. OBJECTIVE. Our goal was to evaluate the efficacy, immunogenicity, and safety of pentavalent rotavirus vaccine at the end of shelf life in healthy infants. PATIENTS AND METHODS. During 2002–2004, 1312 healthy infants ∼6 to 12 weeks old from the United States (47%) and Finland (53%) were randomly assigned to receive 3 oral doses of vaccine (vaccine at ∼1.1 × 107 infectious U per dose) or placebo ∼4 to 10 weeks apart. Infants were to be followed for acute gastroenteritis through 1 rotavirus season after vaccination and for adverse events postvaccination. RESULTS. Three doses of pentavalent rotavirus vaccine at the end of shelf life demonstrated efficacy against rotavirus gastroenteritis caused by human G-serotypes included in the vaccine (G1–G4). Efficacy against severe rotavirus gastroenteritis was 100%, and efficacy against any rotavirus gastroenteritis regardless of severity was 72.5%. A threefold rise in G1 serum neutralizing was observed in 57% and in anti-rotavirus immunoglobulin A in 96% of pentavalent rotavirus vaccine recipients. No statistically significant increase in vomiting, diarrhea, or irritability was observed among pentavalent rotavirus vaccine recipients compared with placebo recipients within the 7-day period from each dose. A statistically significant increase in fevers (≥100.5°F, rectal equivalent) was observed among pentavalent rotavirus vaccine recipients compared with placebo recipients after dose 1. CONCLUSIONS. This pentavalent human-bovine rotavirus vaccine was generally well tolerated, efficacious, and immunogenic at the end of shelf life.

Effect of spectinomycin use on the prevalence of spectinomycin-resistant and of penicillinase-producing Neisseria gonorrhoeae

Because of the high prevalence of penicillinase-producing Neisseria gonorrhoeae in the Republic of Korea, spectinomycin has been used there in the primary treatment of gonococcal infections in U.S. military personnel since 1981, but there have been increasingly frequent reports of treatment failures with spectinomycin. We conducted a clinical study to determine the efficacy of spectinomycin treatment in 124 U.S. servicemen in the Republic of Korea who had urethral gonococcal infections. Ninety-seven patients were treated with spectinomycin alone and evaluated in a follow-up visit. In eight patients (8.2 percent), this treatment was unsuccessful. Antibiotic-sensitivity testing on isolates from seven of the patients with treatment failure demonstrated that six isolates were highly resistant to spectinomycin (minimal inhibitory concentration, greater than or equal to 100 micrograms per milliliter). None of the spectinomycin-resistant strains had become resistant to penicillin, either through the production of penicillinase or through a chromosomal mutation. Although the mechanism of spectinomycin resistance appears to be a chromosomal mutation, these isolates were generally sensitive to other antibiotics. The prevalence of resistance to spectinomycin resulted in the substitution of ceftriaxone for the primary treatment of gonorrhea acquired by U.S. military personnel in the Republic of Korea. We believe that the rapid emergence of spectinomycin resistance in this population mandates a cautious approach to widescale use of the drug and indicates a need to broaden current surveillance programs.

Safety and efficacy of the pentavalent human-bovine (WC3) reassortant rotavirus vaccine in healthy premature infants.

Background: Premature infants seem to be at greater risk of hospitalization from rotavirus gastroenteritis than term infants. Safety and efficacy of the pentavalent human-bovine (WC3) reassortant rotavirus vaccine were assessed in premature infants enrolled in the large-scale, blinded, placebo-controlled rotavirus efficacy and safety trial (REST). Methods: Healthy infants 6–12 weeks of chronologic age at study entry were randomized to receive 3 oral doses of pentavalent rotavirus vaccine or placebo at 4- to 10-week intervals. Infants born at ≤36 weeks of gestational age were eligible if thriving at the time of enrollment. Safety and efficacy were retrospectively assessed in these premature infants comparing vaccine with placebo recipients. Cases of rotavirus gastroenteritis were defined as forceful vomiting and/or ≥3 watery or looser-than-normal stools within a 24-hour period, accompanied by detection of rotavirus antigen in the stool. Results: A total of 2070 infants between 25 and 36 gestational weeks received at least 1 dose of vaccine or placebo; 1005 vaccine recipients and 1061 placebo recipients were evaluable for safety. Serious adverse events occurred in 55 vaccine recipients (5.5%) and 62 placebo recipients (5.8%). In a nested substudy of 308 premature infants evaluable for detailed safety (154 in each group), the frequencies of fever, diarrhea, vomiting, and irritability were comparable between vaccine and placebo recipients. Overall, 3 doses of the pentavalent vaccine reduced the rate of hospitalizations and emergency department visits in premature infants due to rotavirus gastroenteritis by 100% (95% CI: 82.2–100) compared with placebo. The vaccine also prevented 73.0% (95% CI: −2.2–95.2) of rotavirus gastroenteritis cases of any severity. Conclusions: In this post hoc analysis of healthy premature infants, the pentavalent rotavirus vaccine was generally well-tolerated and substantially reduced rotavirus-attributable hospitalizations and emergency department visits compared with placebo. Overall, vaccine safety and efficacy seemed to be generally comparable to the results in the REST study population as a whole. These results support vaccinating healthy premature infants on the same schedule as term infants.

Revaccination with a 23-Valent Pneumococcal Polysaccharide Vaccine Induces Elevated and Persistent Functional Antibody Responses in Adults Aged ⩾65 Years

BACKGROUND Older adults are at high risk of developing invasive pneumococcal disease, but the optimal timing and number of vaccine doses needed to prevent disease among this group are unknown. We compared revaccination with 23-valent pneumococcal polysaccharide vaccine (PN23) with primary vaccination for eliciting initial and persistent functional antibody responses. METHODS Subjects aged > or = 65 years were enrolled. Functional (opsonic) and total immunoglobulin (Ig) G antibody levels were measured following either PN23 primary vaccination (n = 60) or revaccination 3-5 years after receiving a first PN23 vaccination (n = 60). Antibody against vaccine serotypes 4, 14, and 23F was measured at prevaccination (day 0), 30 days after vaccination, and 5 years after vaccination. RESULTS By day 30, both primary vaccination and revaccination induced significant increases in opsonic and IgG antibody levels. Day 30 levels following revaccination were slightly lower but not significantly different than those after primary vaccination. Year 5 levels were similar in both groups and remained significantly higher than prevaccination levels for primary vaccination subjects. There was good agreement between postvaccination opsonic and IgG antibody levels. CONCLUSIONS Revaccination of older adults with PN23 was comparable to primary vaccination for inducing elevated and persistent functional and IgG antibody responses.

Concomitant use of an oral live pentavalent human-bovine reassortant rotavirus vaccine with licensed parenteral pediatric vaccines in the United States

Background: A live pentavalent rotavirus vaccine (PRV) containing 5 human-bovine (WC3) reassortants expressing human serotypes G1, G2, G3, G4 and P1A[8] was evaluated in a blinded, placebo-controlled study. Possible interactions between PRV and concomitantly administered licensed pediatric vaccines were investigated in a United States-based nested substudy (Concomitant Use Study) of the Rotavirus Efficacy and Safety Trial. Methods: From 2002 to 2003, healthy infants approximately 6 to 12 weeks of age at entry were randomized to receive either 3 oral doses of PRV or placebo at 4- to 10-week intervals. Subjects were also to receive combined Haemophilus influenzae type b and hepatitis B vaccine (2 doses), diphtheria and tetanus toxoids and acellular pertussis vaccine (3 doses), inactivated poliovirus vaccine (2 doses) and pneumococcal conjugate vaccine (3 doses) on the same day; oral poliovirus vaccine was not administered. Immunogenicity was assessed by measuring antibody responses to PRV and antigens contained in the licensed vaccines. Cases of rotavirus gastroenteritis were defined by forceful vomiting and/or ≥3 watery or looser-than-normal stools within a 24-hour period, and detection of rotavirus antigen in the stool. Safety was assessed by reporting of adverse events using diary cards. Results: The Concomitant Use Study enrolled 662 subjects in the PRV group and 696 subjects in the placebo group. For the 17 antigens in the concomitantly administered vaccines, antibody responses were similar in PRV and placebo recipients, except for moderately diminished antibody responses to the pertactin component of pertussis vaccine. Efficacy of PRV against rotavirus gastroenteritis of any severity was 89.5% (95% CI = 26.5–99.8%). PRV was generally well tolerated when given concomitantly with the prespecified vaccines. Conclusions: In this study, antibody responses to the concomitantly administered vaccines were generally similar in PRV and placebo recipients. PRV was efficacious and well tolerated when given concomitantly with pediatric vaccines licensed in the United States.

Efficacy of a monovalent human-bovine (116E) rotavirus vaccine in Indian children in the second year of life

UNLABELLED Rotavirus gastroenteritis is one of the leading causes of diarrhea in Indian children less than 2 years of age. The 116E rotavirus strain was developed as part of the Indo-US Vaccine Action Program and has undergone efficacy trials. This paper reports the efficacy and additional safety data in children up to 2 years of age. In a double-blind placebo controlled multicenter trial, 6799 infants aged 6-7 weeks were randomized to receive three doses of an oral human-bovine natural reassortant vaccine (116E) or placebo at ages 6, 10, and 14 weeks. The primary outcome was severe (≥11 on the Vesikari scale) rotavirus gastroenteritis. Efficacy outcomes and adverse events were ascertained through active surveillance. We randomly assigned 4532 and 2267 subjects to receive vaccine and placebo, respectively, with over 96% subjects receiving all three doses of the vaccine or placebo. The per protocol analyses included 4354 subjects in the vaccine and 2187 subjects in the placebo group. The overall incidence of severe RVGE per 100 person years was 1.3 in the vaccine group and 2.9 in the placebo recipients. Vaccine efficacy against severe rotavirus gastroenteritis in children up to 2 years of age was 55.1% (95% CI 39.9 to 66.4; p<0.0001); vaccine efficacy in the second year of life of 48.9% (95% CI 17.4 to 68.4; p=0.0056) was only marginally less than in the first year of life [56.3% (95% CI 36.7 to 69.9; p<0.0001)]. The number of infants needed to be immunized to prevent one episode of severe RVGE in the first 2 years of life was 40 (95% CI 28.0 to 63.0) and for RVGE of any severity, it was 21 (95% CI 16.0 to 32.0). Serious adverse events were observed at the same rates in the two groups. None of the eight intussusception events occurred within 30 days of a vaccine dose and all were reported only after the third dose. The sustained efficacy of the 116E in the second year of life is reassuring. CLINICAL TRIAL REGISTRY The trial is registered with Clinical Trial Registry-India (# CTRI/2010/091/000102) and Clinicaltrials.gov (# NCT01305109).

Experimental Gonococcal Urethritis and Reinfection with Homologous Gonococci in Male Volunteers

Background Reinfection, a common occurrence with gonorrhea, may result from a lack of protective immune response, or from the tremendous gonococcal strain variation. Goal A two-phase study in human volunteers tested whether experimental infection with Neisseria gonorrhoeae MS11mkC would protect against reinfection with the same organisms. Study Design In phase 1, an intraurethral inoculum of 57,000 piliated, transparent (opacity protein–negative [Opa−]) MS11mkC N gonorrhoeae infected 14 of 15 (93%) volunteers. The volunteers were encouraged to delay treatment for at least 5 days. In phase 2, which began 2 weeks after treatment for the initial infection, volunteers were inoculated with 7,100 piliated, Opa− MS11mkC. Results The phase 2 challenge infected 6 of 14 (43%) previously infected volunteers and 5 of 10 (50%) naïve control subjects. Phase 1 volunteers who resisted reinfection were significantly more likely to have had a fourfold or greater increase in lipooligosaccharide immunoglobulin G during phase 1 than those who did not resist reinfection (P = 0.026). Conclusions Although infection did not provide protection from reinfection under the conditions used, the results suggest that immunity to reinfection is more complex than anticipated by the experimental design.