VE303, a Defined Bacterial Consortium, for Prevention of Recurrent Clostridioides difficile Infection: A Randomized Clinical Trial.

Importance: The effect of rationally defined nonpathogenic, nontoxigenic, commensal strains of Clostridia on prevention of Clostridioides difficile infection (CDI) is unknown. Objective: To determine the efficacy of VE303, a defined bacterial consortium of 8 strains of commensal Clostridia, in adults at high risk for CDI recurrence. The primary objective was to determine the recommended VE303 dosing for a phase 3 trial. Design, Setting, and Participants: Phase 2, randomized, double-blind, placebo-controlled, dose-ranging study conducted from February 2019 to September 2021 at 27 sites in the US and Canada. The study included 79 participants aged 18 years or older who were diagnosed with laboratory-confirmed CDI with 1 or more prior CDI episodes in the last 6 months and those with primary CDI at high risk for recurrence (defined as aged ≥75 years or ≥65 years with ≥1 risk factors: creatinine clearance <60 mL/min/1.73 m2, proton pump inhibitor use, remote [>6 months earlier] CDI history). Interventions: Participants were randomly assigned to high-dose VE303 (8.0 × 109 colony-forming units [CFUs]) (n = 30), low-dose VE303 (1.6 × 109 CFUs) (n = 27), or placebo capsules (n = 22) orally once daily for 14 days. Main Outcomes and Measures: The primary efficacy end point was the proportion of participants with CDI recurrence at 8 weeks using a combined clinical and laboratory definition. The primary efficacy end point was analyzed in 3 prespecified analyses, using successively broader definitions for an on-study CDI recurrence: (1) diarrhea consistent with CDI plus a toxin-positive stool sample; (2) diarrhea consistent with CDI plus a toxin-positive, polymerase chain reaction-positive, or toxigenic culture-positive stool sample; and (3) diarrhea consistent with CDI plus laboratory confirmation or (in the absence of a stool sample) treatment with a CDI-targeted antibiotic. Results: Baseline characteristics were similar across the high-dose VE303 (n = 29; 1 additional participant excluded from efficacy analysis), low-dose VE303 (n = 27), and placebo (n = 22) groups. The participants' median age was 63.5 years (range, 24-96); 70.5% were female; and 1.3% were Asian, 1.3% Black, 2.6% Hispanic, and 96.2% White. CDI recurrence rates through week 8 (using the efficacy analysis 3 definition) were 13.8% (4/29) for high-dose VE303, 37.0% (10/27) for low-dose VE303, and 45.5% (10/22) for placebo (P = .006, high-dose VE303 vs placebo). Conclusions and Relevance: Among adults with laboratory-confirmed CDI with 1 or more prior CDI episodes in the last 6 months and those with primary CDI at high risk for recurrence, high-dose VE303 prevented recurrent CDI compared with placebo. A larger, phase 3 study is needed to confirm these findings. Trial Registration: ClinicalTrials.gov Identifier: NCT03788434.

Safety of zoster vaccine in elderly adults following documented herpes zoster.

BACKGROUND: After completion of the Shingles Prevention Study (SPS; Department of Veterans Affairs Cooperative Studies Program Number 403), SPS participants who had initially received placebo were offered investigational zoster vaccine without charge. This provided an opportunity to determine the relative safety of zoster vaccine in older adults following documented herpes zoster (HZ). METHODS: A total of 13 681 SPS placebo recipients who elected to receive zoster vaccine were followed for serious adverse events (SAE) for 28 days after vaccination. In contrast to the SPS, a prior episode of HZ was not a contraindication to receiving zoster vaccine. The SPS placebo recipients who received zoster vaccine included 420 who had developed documented HZ during the SPS. RESULTS: The mean interval between the onset of HZ and the receipt of zoster vaccine in the 420 recipients with prior HZ was 3.61 years (median interval, 3.77 years [range, 3-85 months]); the interval was <5 years for approximately 80% of recipients. The proportion of vaccinated SPS placebo recipients with prior HZ who developed ≥ 1 SAE (0.95%) was not significantly different from that of vaccinated SPS placebo recipients with no prior history of HZ (0.66%), and the distribution of SAEs in the 2 groups was comparable. CONCLUSIONS: These results demonstrate that the general safety of zoster vaccine in older persons is not altered by a recent history of documented HZ, supporting the safety aspect of the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices recommendation to administer zoster vaccine to all persons ≥ 60 years of age with no contraindications, regardless of a prior history of HZ.

Colonization of the live biotherapeutic product VE303 and modulation of the microbiota and metabolites in healthy volunteers.

Manipulation of the gut microbiota via fecal microbiota transplantation (FMT) has shown clinical promise in diseases such as recurrent Clostridioides difficile infection (rCDI). However, the variable nature of this approach makes it challenging to describe the relationship between fecal strain colonization, corresponding microbiota changes, and clinical efficacy. Live biotherapeutic products (LBPs) consisting of defined consortia of clonal bacterial isolates have been proposed as an alternative therapeutic class because of their promising preclinical results and safety profile. We describe VE303, an LBP comprising 8 commensal Clostridia strains under development for rCDI, and its early clinical development in healthy volunteers (HVs). In a phase 1a/b study in HVs, VE303 is determined to be safe and well-tolerated at all doses tested. VE303 strains optimally colonize HVs if dosed over multiple days after vancomycin pretreatment. VE303 promotes the establishment of a microbiota community known to provide colonization resistance.

Safety and antibody response, including antibody persistence for 5 years, after primary vaccination or revaccination with pneumococcal polysaccharide vaccine in middle-aged and older adults.

BACKGROUND: This study assessed antibody levels for 5 years after primary vaccination or revaccination with 23-valent pneumococcal polysaccharide vaccine (PN23). METHODS: Subjects were enrolled into 4 study groups by age (50-64 or > or = 65 years) and prior vaccination status (no prior vaccination or 1 vaccination 3-5 years previously). Blood was obtained on day 0 (before primary vaccination or revaccination), day 30, day 60, and annually during years 2-5. Levels of immunoglobulin G (IgG) to 8 vaccine serotypes were measured by enzyme-linked immunosorbent assay. RESULTS: Of 1008 enrolled subjects, 551 completed year 5. For each serotype and age group, baseline geometric mean concentrations (GMCs) of IgG were higher in revaccination than primary vaccination subjects. Primary vaccination or revaccination with PN23 induced significant increases in levels of antibody to all serotypes tested. Although day 30 and 60 antibody levels tended to be modestly lower after revaccination, study groups had similar GMCs at later time points. For serotypes 4, 6B, 8, 9V, 12F, 14, and 23F, GMCs during years 2-5 after primary vaccination or revaccination remained higher than in vaccine-naive persons. Levels of antibody to serotype 3 returned to baseline by year 2. CONCLUSIONS: Both primary vaccination and revaccination with PN23 induce antibody responses that persist during 5 years of observation.

Influence of age and nature of primary infection on varicella-zoster virus-specific cell-mediated immune responses.

BACKGROUND: Varicella-zoster virus (VZV)-specific cell-mediated immunity is important for protection against VZV disease. We studied the relationship between VZV cell-mediated immunity and age after varicella or VZV vaccination in healthy and human immunodeficiency virus (HIV)-infected individuals. METHODS: VZV responder cell frequency (RCF) determinations from 752 healthy and 200 HIV-infected subjects were used to identify group-specific regression curves on age. RESULTS: In healthy individuals with past varicella, VZV RCF peaked at 34 years of age. Similarly, VZV-RCF after varicella vaccine increased with age in subjects aged <1 to 43 years. In subjects aged 61-90 years, VZV RCF after zoster vaccine decreased with age. HIV-infected children had lower VZV RCF estimates than HIV-infected adults. In both groups, VZV RCF results were low and constant over age. Varicella vaccination of HIV-infected children with CD4 levels 20% generated VZV RCF values higher than wild-type infection and comparable to vaccine-induced responses of healthy children. CONCLUSIONS: In immunocompetent individuals with prior varicella, VZV RCF peaked in early adulthood. Administration of varicella vaccine to HIV-infected or uninfected individuals aged >5 years generated VZV RCF values similar to those of immunocompetent individuals with immunity induced by wild-type infection. A zoster vaccine increased the VZV RCF of elderly adults aged <75 years to values higher than peak values induced by wild-type infection.

Concomitant administration of zoster and pneumococcal vaccines in adults ≥60 years old.

This study evaluated safety & immunogenicity of ZOSTAVAX® (zoster vaccine: ZV) administered concomitantly versus nonconcomitantly with PNEUMOVAX® 23 (pneumococcal vaccine: PPV23). This randomized, double-blind, placebo-controlled study enrolled 473 subjects ≥60 years old in 1:1 ratio to receive ZV & PPV23 concomitantly (Day 1) or nonconcomitantly (PPV23 Day 1, ZV Week 4). Blood samples obtained for pneumococcal polysaccharide (PnPs) antibody (Ab) testing by enzyme-linked immunosorbent assay (ELISA) and varicella-zoster virus (VZV) Ab testing by glycoprotein ELISA. Subjects followed for adverse experiences (AEs) for 28 days postvaccination. Mean baseline VZV geometric mean titers (GMT) in nonconcomitant group were lower than concomitant group. Four weeks postvaccination with ZV, VZV Ab response in concomitant group was not similar to nonconcomitant group; estimated VZV GMT ratio [concomitant/nonconcomitant] was 0.70 (95% CI, 0.61-0.80). VZV Ab response was acceptable in concomitant group; estimated geometric mean foldrise (GMFR) from baseline was 1.9 (95% CI, 1.7-2.1). PnPs serotype-specific Ab responses were similar in both groups. All 6 reported serious AEs were deemed not related to study vaccine. Postvaccination of ZV, incidence of injection-site AEs was similar in both groups; clinical AEs were numerically but not significantly higher in nonconcomitant group. In summary, VZV GMT Ab response induced by ZV administered concomitantly with PPV23 was inferior to that induced nonconcomitantly. These results indicate that, to avoid a potential decrease in ZV immunogenicity, ZV & PPV23 should not be given concomitantly. Concomitant administration did not affect response to PPV23 serotypes tested. When administered concomitantly, ZV & PPV23 vaccines were generally well tolerated.

Immunogenicity of Oka/Merck varicella vaccine in children vaccinated at 12-14 months of age versus 15-23 months of age.

OBJECTIVE: Recent reports suggest that breakthrough varicella may be more common in children when the Oka/Merck varicella vaccine is given at 12-14 months of age than when it is given at older ages. An analysis of 5 postlicensure clinical trials with this vaccine was conducted to evaluate immune response relative to the age of the vaccine recipient. METHODS: In 5 clinical trials, 3771 children, 12 through 23 months of age with no history of varicella, received an injection of varicella vaccine. Varicella-zoster virus (VZV) antibody was measured 6 weeks postvaccination by glycoprotein enzyme-linked immunosorbent assay (gpELISA), an assay that correlates with neutralizing antibody. Endpoints evaluated were the response rate (percent of subjects with VZV antibody > or =5 gpELISA units/mL, a titer shown to correlate with protection) and geometric mean titer (GMT) of VZV antibody. Each endpoint was compared across 3 age groups (12-14, 15-17, and 18-23 months of age). Response rates by initial VZV serostatus were evaluated for children vaccinated at 12-14 months of age to assess whether maternal antibody had an impact on the immune response. RESULTS: The response rates were similar among 12-14, 15-17, and 18-23 month olds (93.8, 90.8, and 93.1%, respectively); GMTs were significantly higher among the 12-14 month olds (15.1, 13.5, and 13.7 gpELISA units/mL, respectively). Among children 12-14 months of age, response rates and GMTs were similar regardless of their prevaccination VZV serostatus. CONCLUSIONS: Oka/Merck varicella vaccine is highly immunogenic when given to children 12-14 months of age. The immunogenicity profile is similar to that of children 15-17 and 18-23 months of age. The presence of low titers of VZV antibody before vaccination did not influence vaccine response in 12-14 month olds. These results support current recommendations for universal varicella vaccination beginning at 12 months of age.

Safety and immunogenicity profile of the concomitant administration of ZOSTAVAX and inactivated influenza vaccine in adults aged 50 and older.

OBJECTIVES: To evaluate the safety and immunogenicity of ZOSTAVAX administered concomitantly with inactivated influenza vaccine or sequentially in adults aged 50 and older. DESIGN: Randomized, blinded, placebo-controlled study. SETTING: Thirteen U.S. and seven European study sites. PARTICIPANTS: Three hundred eighty-two concomitantly, 380 sequentially vaccinated subjects. INTERVENTION: The concomitant vaccination group received influenza vaccine and ZOSTAVAX at separate injection sites on Day 1 and placebo at Week 4. The nonconcomitant vaccination group received influenza vaccine and placebo at separate injection sites on Day 1 and ZOSTAVAX at Week 4. MEASUREMENTS: Primary safety endpoints: vaccine-related serious adverse experiences (AEs) within 28 days postvaccination (PV); and diary card-prompted local and systemic AEs. Primary immunogenicity endpoints: geometric mean titer (GMT) and geometric mean fold rise (GMFR) from baseline of varicella-zoster virus (VZV) antibody (Ab) at 4 weeks PV according to glycoprotein enzyme-linked immunosorbent assay (gpELISA) and GMT of influenza Ab for the three vaccine strains (2005-2006 influenza season) at 4 weeks PV according to hemagglutination inhibition assay. Secondary immunogenicity endpoint: influenza seroconversion rates (SCRs). RESULTS: No serious AEs related to ZOSTAVAX were observed during the study. VZV Ab GMTs 4 weeks PV for the concomitant and sequential groups were 554 and 597 gpELISA U/mL, respectively. The estimated VZV Ab GMT ratio was 0.9 (95% confidence interval (CI)=0.8-1.0), indicating noninferior (P<.001 for the null hypothesis of GMT ratio <0.67) responses. Estimated VZV Ab GMFR from baseline in the concomitant group was 2.1 (95% CI=2.0-2.3), indicating acceptable fold rise. Estimated GMT ratios (concomitant/sequential) for influenza strains A(H1N1), A(H3N2), and B were 0.9 (95% CI=0.8-1.1), 1.1 (95% CI=0.9-1.3), and 0.9 (95% CI=0.8-1.1), respectively, and SCRs were comparable across both groups, with more than 85% achieving titers of 1:40 or greater, meeting regulatory criteria. CONCLUSION: ZOSTAVAX and influenza vaccine given concomitantly are generally well tolerated in adults aged 50 and older. Ab responses were similar whether ZOSTAVAX and influenza vaccine were given concomitantly or sequentially.

Safety, tolerability, and immunogenicity of zoster vaccine in subjects on chronic/maintenance corticosteroids.

BACKGROUND: This randomized, placebo-controlled study assessed the safety, tolerability, and immunogenicity of live virus zoster vaccine (ZV) in individuals receiving chronic/maintenance systemic corticosteroid therapy (daily dose equivalent of 5-20mg prednisone) for ≥2 weeks prior to vaccination and ≥6 weeks postvaccination. METHODS: Subjects were followed for adverse experiences (AEs), exposure to varicella or herpes zoster (HZ), or development of varicella/varicella-like or HZ/HZ-like rashes for 42 days postvaccination (primary safety follow-up period) and for serious AEs (SAEs) through Day 182 postvaccination (secondary follow-up period). Varicella-zoster virus (VZV) antibody titers by glycoprotein enzyme-linked immunosorbent assay (gpELISA) were measured at baseline and at Week 6 postvaccination. RESULTS: The proportions of subjects reporting systemic AEs and SAEs were similar in both groups. A higher percentage of subjects reported injection-site AEs in the ZV group (21.5%) than in the placebo group (12.1%). One SAE of ophthalmic HZ (onset Day 16 postvaccination) was reported in the ZV group and deemed vaccine-related by the study investigator; however, PCR testing confirmed the presence of wild-type (not vaccine strain) VZV. Geometric mean titer (GMT) at 6 weeks postvaccination was higher for ZV recipients than placebo recipients, with estimated geometric mean fold rises (GMFR) of 2.3 (CI: 2.0, 2.7) and 1.1 (CI: 1.0, 1.2) respectfully. CONCLUSIONS: In adults ≥60 years old on chronic/maintenance corticosteroids, ZV was generally well tolerated and immunogenic. The VZV-specific gpELISA antibody GMT at 6 weeks postvaccination and the GMFR from baseline to 6 weeks postvaccination were higher in the ZV group than in the placebo group.

Varicella-zoster virus-specific enzyme-linked immunospot assay responses and zoster-associated pain in herpes zoster subjects.

Varicella-zoster virus (VZV)-specific cell-mediated immunity (CMI) responses were compared over time following an episode of herpes zoster (HZ) with those of age-, race-, and gender-matched healthy controls (HC) without HZ, using a validated gamma interferon (IFN-γ) enzyme-linked immunospot (ELISPOT) assay. The zoster brief-pain inventory (ZBPI) was used to assess zoster-associated pain. HZ patients (n = 140) had significantly higher IFN-γ ELISPOT responses to VZV antigen than did HC (n = 140). ELISPOT geometric mean count (GMC) responses (with 95% confidence intervals [CI]) for subjects who presented within 72 h were as follows: for HZ patients ≥ 60 years of age, at day 0 the GMC was 110 and at week 2 the GMC was 235; for HZ patients 21 to 59 years of age, at day 0 the GMC was 111 and at week 2 the GMC was 198; for HC ≥ 60 years of age, at day 0 the GMC was 19 and at week 2 the GMC was 18; and for HC 21 to 59 years of age, at day 0 the GMC was 59 and at week 2 the GMC was 56. The mean pain score (95% CI) across age groups at 1 week postrash (n = 106) was 6.0 (5.5, 6.5) and at 2 weeks postrash (n = 119) was 3.5 (2.9, 4.0). The percentage of HZ patients with substantial pain (score ≥ 3) at 6 weeks postrash increased with age from 8% for patients 21 to 49 years of age to 16% for patients 50 to 59 years of age to 22% for patients ≥ 60 years of age. The VZV-specific CMI response was substantially boosted by an episode of HZ, as measured by ELISPOT results. Older adults had lower VZV-specific cellular immunity than younger subjects at baseline, but the boosting effect of HZ was substantial for all age groups. HZ patients experienced considerable zoster-associated acute (1 to 2 weeks after rash) pain across age groups, while chronic pain increased with age.

Safety, tolerability, and immunogenicity after 1 and 2 doses of zoster vaccine in healthy adults ≥60 years of age.

BACKGROUND: Incidence and severity of herpes zoster (HZ) and postherpetic neuralgia increase with age, associated with age-related decrease in immunity to varicella-zoster virus (VZV). One dose of zoster vaccine (ZV) has demonstrated substantial protection against HZ; this study examined impact of a second dose of ZV. METHODS: Randomized, double-blind, multicenter study with 210 subjects ≥60 years old compared immunity and safety profiles after one and two doses of ZV, separated by 6 weeks, vs. placebo. Immunogenicity was evaluated using VZV interferon-gamma (IFN-γ) enzyme-linked immunospot (ELISPOT) assay and VZV glycoprotein enzyme-linked immunosorbent antibody (gpELISA) assay. Adverse experiences (AEs) were recorded on a standardized Vaccination Report Card. RESULTS: No serious vaccine-related AEs occurred. VZV IFN-γ ELISPOT geometric mean count (GMC) of spot-forming cells per 10(6) peripheral blood mononuclear cells increased in the ZV group from 16.9 prevaccination to 49.5 and 32.8 at 2 and 6 weeks postdose 1, respectively. Two weeks, 6 weeks and 6 months postdose 2, GMC was 44.3, 42.9, and 36.5, respectively. GMC in the placebo group did not change during the study. The peak ELISPOT response occurred ∼2 weeks after each ZV dose. The gpELISA geometric mean titers (GMTs) in the ZV group were higher than in the placebo group at 6 weeks after each dose. Correlation between the IFN-γ ELISPOT and gpELISA assays was poor. CONCLUSIONS: ZV was generally well-tolerated and immunogenic in adults ≥60 years old. A second dose of ZV was generally safe, but did not boost VZV-specific immunity beyond levels achieved postdose 1.

Safety and immunogenicity of three different formulations of a liquid hexavalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae b conjugate-hepatitis B vaccine at 2, 4, 6 and 12-14 months of age.

The current recommended infant vaccination schedules require many injections at multiple sites, which increase stress for infants and parents and may create challenges to vaccination compliance. Therefore, combination vaccines, which reduce the number of injections at each medical visit, can be an essential method to improve compliance. The objective of this study was to assess the safety and immunogenicity of an investigational, liquid, hexavalent, pediatric vaccine at 2, 4, 6, and 12-14 months of age. In this multicenter, open-label controlled study, 756 infants were randomized in approximately equal numbers to receive 0.5mL intramuscular dose of diptheria-tetanus-pertussis-polio-Haemophilus influenzae type b+hepatitis B vaccine, or 1 of 3 double-blind investigational formulations. All formulations included a hepatitis B surface antigen (HBsAg) concentration of 10µg/0.5mL. The three hexavalent vaccine formulations used in this study contained either Hib polyribosylribitol phosphate (PRP) conjugate component (tetanus toxoid [PRP-T, 12µg] or Neisseria meningitidis outer membrane protein complex [PRP-OPMC, 3µg or 6µg]): a minimum acceptable postdose 3 antibody response rate for each antigen was defined by the lower limit of a 95% confidence interval exceeding a prespecified target. Rates of adverse events (AEs) were similar among groups, with a trend for increased solicited vaccine-related injection-site reactions (pain, erythema, swelling) with increasing PRP-OMPC dose. No serious vaccine-related AEs were reported in the investigational groups. Both PRP-OMPC formulations met prespecified acceptability criteria for all antigens: PRP, HBsAg, pertussis, diphtheria, tetanus and poliovirus. The PRP-T formulation met the acceptability criterion for antibody responses to all antigens other than PRP at postdose 3. Postdose 4 responses were adequate for all antigens in all formulations. All vaccine formulations were well-tolerated. Both PRP-OMPC formulations met prespecified immunogenicity criteria of PRP-OMPC evaluation.

Safety, tolerability, and immunogenicity of zoster vaccine in subjects with a history of herpes zoster.

BACKGROUND: Prior clinical studies of zoster vaccine enrolled subjects without a history of herpes zoster (HZ), so there are limited data on safety and immunogenicity in vaccinees with a prior history of HZ. This study was conducted to evaluate the safety and immunogenicity of zoster vaccine recipients who had a prior episode of HZ. METHODS: A total of 101 subjects > or = 50 years of age with a prior history of HZ were enrolled. They were stratified by number of years since their HZ (5 to 9 years and > or = 10 years, in an approximate 2:1 ratio), and randomized 1:1 to one of two vaccination groups. On day 1, Group I was administered zoster vaccine and Group II received placebo. At week 4, Group I received placebo and Group II received zoster vaccine. Subjects were followed for adverse experiences (AEs), exposure to varicella or HZ, and development of any varicella/varicella-like or HZ/HZ-like rashes, for 28 days after each injection. Blood samples were obtained prior to study injection on day 1 and week 4, and at week 8. Serum was assessed for varicella-zoster virus (VZV) antibody concentration by glycoprotein enzyme-linked immunosorbent assay. RESULTS: No serious AEs were reported within the 28-day safety follow-up period following any vaccination. Although a higher percentage of subjects reported injection-site AEs after receiving zoster vaccine than did placebo recipients, the proportion of subjects reporting systemic clinical AEs was similar in both groups. Zoster vaccine induced a VZV antibody response at 4 weeks post-vaccination. The estimated geometric mean titer (GMT) ratio (vaccine/placebo) was 2.07 (95% CI: 1.48, 2.88). The geometric mean fold-rise (GMFR) from prevaccination to week 4 post-vaccination was 2.1 in zoster vaccine recipients, versus 1.0 in placebo recipients. CONCLUSIONS: In HZ history-positive adults > or = 50 years of age, zoster vaccine: (1) was well tolerated; and (2) significantly boosted the level of VZV antibody from baseline to 4 weeks post-vaccination as measured by GMT and GMFR. These data support the Advisory Committee on Immunization Practices' recommendation for routine zoster vaccination for all immunocompetent persons >/=60 years of age irrespective of HZ history.

Comparison of the levels of immunogenicity and safety of Zostavax in adults 50 to 59 years old and in adults 60 years old or older.

Zostavax has been shown to be efficacious in the prevention of herpes zoster and generally well tolerated in clinical trials among subjects 60 years old or older. This prespecified combined analysis from two studies compares the levels of immunogenicity and safety of Zostavax in subjects 50 to 59 years old versus those in subjects >or=60 years old. Varicella-zoster virus (VZV) antibody (Ab) titers were measured by glycoprotein enzyme-linked immunosorbent assay at baseline and 4 weeks postvaccination. Noninferiority was evaluated by estimated geometric mean severalfold rise (GMFR) ratio (50 to 59 years old/>or=60 years old) and two-sided 95% confidence interval (CI). Success was defined by a lower bound (LB) of the 95% CI of the GMFR ratio of >0.67. Acceptability of postvaccination VZV Ab was defined by an LB of the 95% CI of the GMFR of >1.4. Safety data were recorded for 28 days postvaccination by standardized vaccination report card. The estimated GMFRs from baseline to 4 weeks postvaccination were 2.6 (95% CI, 2.4, 2.9) in subjects 50 to 59 years old and 2.3 (95% CI, 2.1, 2.4) in subjects >or=60 years old. The estimated GMFR ratio (50 to 59 years old/>or=60 years old) was 1.13 (95% CI, 1.02, 1.25). No serious Zostavax-related adverse experiences were reported. After a dose of Zostavax, the GMFR of the VZV Ab response in subjects 50 to 59 years old was noninferior to that in subjects >or=60 years old. The VZV Ab response was acceptable in both age groups. Zostavax was generally well tolerated in both age groups.

Safety and immunogenicity of a hexavalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae b conjugate-hepatitis B vaccine at 2, 3, 4, and 12-14 months of age.

Combination vaccines improve parental and provider satisfaction and schedule compliance by decreasing the number of injections. In a Phase 2, randomized, double-blind, multicenter study, we compared four formulations of a liquid, hexavalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae b conjugate-hepatitis B virus (DTaP-IPV-Hib-HBV) vaccine in 708 infants immunized at 2, 3, 4, and 12-14 months of age. The formulations contained identical DTaP and IPV components, differing in the contents of Hib polyribosylribitol phosphate (PRP) conjugate component (tetanus-toxoid [PRP-T, 12microg] or Neisseria meningitidis outer-membrane-protein-complex [PRP-OMPC, 3microg or 6microg]), and in hepatitis B surface antigen (HBsAg, 10microg or 15microg). A minimum acceptable postdose 3 antibody response rate was defined by the lower limit of the 95% confidence interval exceeding a prespecified target. Rates of adverse events (AEs) were similar among groups, with a trend for increased solicited injection-site reactions (pain, redness, swelling) with increasing PRP-OMPC and HBsAg concentration. Serious AEs reported by eight subjects were not considered to be vaccine related. All PRP-OMPC formulations met prespecified acceptability criteria for postdose 3 immunogenicity for all antigens: PRP, HBsAg, pertussis, diphtheria, tetanus and polio. Apart from the Hib response, the postdose 3 responses obtained with the PRP-T formulation met the acceptability criterion for each antigen. Postdose 4 responses were acceptable for all antigens in all formulations. All vaccine formulations were well tolerated. The three PRP-OMPC formulations met prespecified immunogenicity criteria, and the one with the lowest PRP-OMPC concentration was selected for further optimization of immunogenicity.

A double-blind, randomized, controlled, multicenter safety and immunogenicity study of a refrigerator-stable formulation of Zostavax.

The vaccine Zostavax has been shown to prevent herpes zoster (HZ) and postherpetic neuralgia and is recommended for individuals > or =60 years of age. This study compared the safety and the immunogenicity of a refrigerator-stable formulation (Zostavax refrigerated) with those of the current formulation (Zostavax frozen) in subjects > or =50 years of age. Subjects with a negative history for HZ were randomized 1:1 to receive one dose of either formulation. Enrollment was stratified 1:2 by age (50 to 59 years and > or =60 years). Safety was evaluated for 28 days postvaccination. Varicella-zoster virus (VZV) antibody responses were measured by a glycoprotein enzyme-linked immunosorbent assay (gpELISA). The primary endpoints were the VZV antibody geometric mean titer (GMT; day 28), the VZV antibody geometric mean rise (GMR; days 1 to 28), and the incidence of vaccine-related serious adverse experiences (AEs) over 28 days. The refrigerated (n = 182) and frozen (n = 185) formulations induced similar GMTs (727.4 and 834.4 gpELISA units/ml, respectively); the estimated GMT ratio (refrigerated formulation/frozen formulation) was 0.87 (95% confidence interval, 0.71 to 1.07). The GMRs were 2.6- and 2.9-fold, respectively. No vaccine-related serious AEs were reported in either group, and the safety profiles of the formulations were generally similar. The frequencies of injection-site AEs during follow-up were 35.6% and 46.4% in the refrigerated and the frozen formulation groups, respectively, and were generally mild. The frequencies of systemic AEs were similar in the two groups, and those of vaccine-related AEs were approximately 6% in both groups. The refrigerator-stable formulation of Zostavax has an acceptable safety profile and is as immunogenic as the frozen formulation; thus, the vaccine may be used in clinical settings where freezer availability is limited.

Safety, tolerability, and immunogenicity of a two-dose regimen of high-titer varicella vaccine in subjects > or =13 years of age.

A new manufacturing process, known as process upgrade varicella vaccine (PUVV) was developed for a refrigerated formulation of varicella vaccine and for an investigational zoster vaccine. Safety and tolerability of a two-dose regimen of high-titered (approximately 50,000 PFU) PUVV were compared to a lower-titer formulation (approximately 5400 PFU) of VARIVAX; in 1366 healthy subjects > or =13 years old. Only one vaccine-related clinical serious adverse experience (pruritus; no hospitalization) was reported, in the VARIVAX group. Injection-site adverse experiences following any dose were higher in the PUVV group, 70.0%, than in the VARIVAX group, 56.2%, but generally were mild. Immunogenicity were similar in both groups in seronegative subjects. PUVV was generally well tolerated, and elicited an immune response similar to that induced by the marketed formulation of VARIVAX.

Safety and immunogenicity of two formulations of a hexavalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae conjugate-hepatitis B vaccine in 15 to 18-month-old children.

Combination vaccines decrease the number of injections and improve parental satisfaction and vaccination schedule compliance. In a phase 1, randomized, partially-blinded, single-dose booster study, we evaluated two formulations of an investigational liquid hexavalent vaccine containing diphtheria, tetanus, acellular pertussis (5-component), inactivated poliovirus, Haemophilus influenzae b conjugate and hepatitis B surface antigen (DTaP-IPV-Hib-HBV) in 60 healthy toddlers, 15 to 18 months of age, who had been primed with three doses of a licensed pentavalent diphtheria, tetanus, acellular pertussis (5-component), inactivated poliovirus, Haemophilus influenzae b conjugate (DTaP-IPV//PRP-T) vaccine. The DTaP-IPV//PRP-T vaccine was used as a control in 30 subjects. The investigational formulations, which contained the same DTaP-IPV components, differed only in Hib (content and conjugate) and HBV (content) (PRP-T/HBV10 = 12 mug Hib tetanus toxoid conjugate with 10 microg HBsAg; PRP-OMPC/HBV15 = 6 microg Hib Neisseria meningitidis outer membrane protein complex with 15 microg HBsAg). Injection-site pain, redness and swelling were reported by 46.7%, 46.7%, and 20.0% of the licensed vaccine recipients, 43.3%, 43.3%, and 26.7% of PRP-T/HBV10 recipients and 70.0%, 46.7%, and 46.7% of PRP-OMPC/HBV15 recipients, respectively. Fever > or = 37.8 degrees C and irritability were reported by 0% and 16.7% of licensed vaccine recipients, 10.3% and 23.3% of PRP-T/HBV10 recipients and 30.0% and 16.7% of PRP-OMPC/HBV15 recipients, respectively. There were no apparent differences between the groups in the proportion of participants achieving predefined, threshold or seroprotective immune responses. Geometric mean antibody levels for all antigens were similar except for anti-PRP levels, which were 19.0 microg/mL in recipients of the licensed vaccine, 40.8 microg/mL in PRP-T/HBV10 recipients and 9.4 microg/mL in PRP-OMPC/HBV15 recipients. We conclude that the hexavalent formulations appear generally well tolerated and immunogenic as a booster dose in these toddlers.

Decline in varicella-zoster virus (VZV)-specific cell-mediated immunity with increasing age and boosting with a high-dose VZV vaccine.

The safety and immunogenecity of a booster dose of live attenuated varicella-zoster virus (VZV) vaccine was evaluated in 196 healthy subjects, >or=60 years old, who had already received a VZV vaccine >5 years before. This repeat booster dose was well tolerated. Cell-mediated immunity (CMI) to VZV was measured by an interferon-gamma (IFN-gamma) enzyme-linked immunosorbent spot-forming cell (ELISPOT) assay and a limiting dilution responder cell frequency (RCF) assay. Prevaccination responses decreased as a function of increasing age but were detectable in all subjects by use of the IFN-gamma ELISPOT assay. In most subjects, VZV-specific CMI was increased at 6 weeks postvaccination. The magnitude of the vaccine-induced IFN-gamma ELISPOT response was inversely related to prevaccination values. Although there was a significant correlation between the IFN-gamma ELISPOT and RCF assays, the ELISPOT assay had greater sensitivity and a wider dynamic range. A live attenuated VZV vaccine is safe and immunogenic in an elderly population, and the vaccine-induced immunity may be monitored by the IFN-gamma ELISPOT assay.