Replication and Excretion of the Live Attenuated Tetravalent Dengue Vaccine CYD-TDV in a Flavivirus-Naive Adult Population: Assessment of Vaccine Viremia and Virus Shedding.

Background: We assessed replication and excretion of the live attenuated tetravalent dengue vaccine (CYD-TDV) into biological fluids following vaccination in dengue-naive adults in Australia. Methods: Vaccinal viremia/shedding was assessed in a subset of participants enrolled in a lot-to-lot consistency study; 95 participants received 3 subcutaneous doses of CYD-TDV from phase 2/3 lots of the vaccine, and 8 received placebo; doses were administered 6 months apart. Quantitative reverse-transcription polymerase chain reaction (qR-PCR) analysis was used to initially detect the yellow fever virus (YFV) core protein gene in the backbone of CYD-TDV in serum, saliva and urine, followed by serotype-specific qRT-PCR analysis of samples positive for YFV by qRT-PCR (lower limit of detection, 5.16 GEq/mL). Results: YFV viremia was detected by qRT-PCR in 69.5% of participants (66 of 95) who received CYD-TDV, mainly 6-14 days after injection 1. The serotypes detected were serotype 4 (in 68.2% of participants [45 of 95]), serotype 3 (in 19.7% [13 of 95]), and serotype 1 (in 12.1% [8 of 95]); serotype 2 was not detected. None of the placebo recipients had vaccinal viremia/shedding. No participants had detectable viral shedding into saliva at levels above the lower limit of quantitation. Two participants had low-level viral shedding (serotype 3) in urine (5.47 and 5.77 GEq/mL). None of the participants with viremia or shedding experienced concomitant fever. Conclusions: Low-level vaccinal viremia may occur following vaccination with CYD-TDV, but this is not associated with any symptom or adverse event. Clinical Trials Registration: NCT01134263.

Clinical efficacy and safety of a novel tetravalent dengue vaccine in healthy children in Asia: a phase 3, randomised, observer-masked, placebo-controlled trial.

BACKGROUND: An estimated 100 million people have symptomatic dengue infection every year. This is the first report of a phase 3 vaccine efficacy trial of a candidate dengue vaccine. We aimed to assess the efficacy of the CYD dengue vaccine against symptomatic, virologically confirmed dengue in children. METHODS: We did an observer-masked, randomised controlled, multicentre, phase 3 trial in five countries in the Asia-Pacific region. Between June 3, and Dec 1, 2011, healthy children aged 2-14 years were randomly assigned (2:1), by computer-generated permuted blocks of six with an interactive voice or web response system, to receive three injections of a recombinant, live, attenuated, tetravalent dengue vaccine (CYD-TDV), or placebo, at months 0, 6, and 12. Randomisation was stratified by age and site. Participants were followed up until month 25. Trial staff responsible for the preparation and administration of injections were unmasked to group allocation, but were not included in the follow-up of the participants; allocation was concealed from the study sponsor, investigators, and parents and guardians. Our primary objective was to assess protective efficacy against symptomatic, virologically confirmed dengue, irrespective of disease severity or serotype, that took place more than 28 days after the third injection. The primary endpoint was for the lower bound of the 95% CI of vaccine efficacy to be greater than 25%. Analysis was by intention to treat and per procotol. This trial is registered with ClinicalTrials.gov, number NCT01373281. FINDINGS: We randomly assigned 10,275 children to receive either vaccine (n=6851) or placebo (n=3424), of whom 6710 (98%) and 3350 (98%), respectively, were included in the primary analysis. 250 cases of virologically confirmed dengue took place more than 28 days after the third injection (117 [47%] in the vaccine group and 133 [53%] in the control group). The primary endpoint was achieved with 56·5% (95% CI 43·8-66·4) efficacy. We recorded 647 serious adverse events (402 [62%] in the vaccine group and 245 [38%] in the control group). 54 (1%) children in the vaccine group and 33 (1%) of those in the control group had serious adverse events that happened within 28 days of vaccination. Serious adverse events were consistent with medical disorders in this age group and were mainly infections and injuries. INTERPRETATION: Our findings show that dengue vaccine is efficacious when given as three injections at months 0, 6, and 12 to children aged 2-14 years in endemic areas in Asia, and has a good safety profile. Vaccination could reduce the incidence of symptomatic infection and hospital admission and has the potential to provide an important public health benefit. FUNDING: Sanofi Pasteur.

Safety and immunogenicity of 4 intramuscular double doses and 4 intradermal low doses vs standard hepatitis B vaccine regimen in adults with HIV-1: a randomized controlled trial.

CONTEXT: Alternative schedules more immunogenic than the standard hepatitis B vaccine regimen are needed in patients with human immunodeficiency virus 1 (HIV-1) infection. OBJECTIVE: To compare the safety and immunogenicity of 4 intramuscular double-dose and 4 intradermal low-dose regimens vs the standard hepatitis B vaccine regimen. DESIGN, SETTING, AND PARTICIPANTS: An open-label, multicenter, 1:1:1 parallel-group, randomized trial conducted between June 28, 2007, and October 23, 2008 (date of last patient visit, July 3, 2009) at 33 centers in France with patients enrolled in French National Agency for Research on AIDS and Viral Hepatitis trials in adults with HIV-1 infection who were hepatitis B virus (HBV) seronegative and having CD4 cell counts of more than 200 cells/µL. INTERVENTION: Patients were randomly assigned to receive 3 intramuscular injections of the standard dose (20 µg) of recombinant HBV vaccine at weeks 0, 4, and 24 (IM20 × 3 group, n = 145); 4 intramuscular double doses (40 µg [2 injections of 20 µg]) of recombinant HBV vaccine at weeks 0, 4, 8, and 24 (IM40 × 4 group, n = 148); or 4 intradermal injections of low doses (4 µg [1/5 of 20 µg]) of recombinant HBV vaccine at weeks 0, 4, 8, and 24 (ID4 × 4 group, n = 144). MAIN OUTCOME MEASURES: Percentage of responders at week 28, defined as patients with hepatitis B surface antibody (anti-HBs) of at least 10 mIU/mL in patients who received at least 1 dose of vaccine. Patients with missing anti-HBs titer measurement at the final follow-up visit at week 28 were considered as nonresponders in the primary (efficacy) analysis. RESULTS: A total of 437 patients were randomized to the 3 study groups, of whom 11 did not receive any vaccine. Of these, 396 had available anti-HBs titers at week 28. The percentage of responders at week 28 was 65% (95% confidence interval [CI], 56%-72%) in the IM20 × 3 group (n = 91), 82% (95% CI, 77%-88%) in the IM40 × 4 group (n = 119) (P < .001 vs IM20 × 3 group), and 77% (95% CI, 69%-84%) in the ID4 × 4 group (n = 108) (P = .02 vs IM20 × 3 group). No safety signal and no effect on CD4 cell count or viral load were observed. CONCLUSION: In adults with HIV-1, both the 4 intramuscular double-dose regimen and the 4 intradermal low-dose regimen improved serological response compared with the standard HBV vaccine regimen. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00480792.

Similar immunogenicity of the A/H1N1 2009 pandemic influenza strain when used as a monovalent or a trivalent vaccine.

BACKGROUND: The WHO recommended including the A (H1N1) 2009 pandemic strain in the influenza vaccines for use in the 2010-2011 northern hemisphere (NH) influenza season. The immunogenicity and safety of the trivalent split inactivated vaccine (Vaxigrip®) NH 2010-2011 formulation was compared to that observed for the corresponding non-adjuvanted monovalent A (H1N1) pandemic vaccine (Panenza®), when tested in similar populations of adult and elderly volunteers. METHODS: The monovalent vaccine was evaluated in two clinical trials, conducted respectively in both adult and elderly subjects and in a population of adults. The trivalent vaccine was evaluated in a clinical study that enrolled both adult and elderly subjects. Antibody titers were measured in serum samples drawn at day 0 (before vaccination) and 21 days after one vaccine injection using the same hemagglutination inhibition (HI) assay method. The occurrence of adverse events was reported up to 21 days after vaccination. RESULTS: Before immunization in the three studies, most of the volunteers had antibody titers below seroprotective levels against the pandemic A(H1N1) 2009 virus. After vaccination, in each trial and in each age group, high seroprotection rates, GMT ratios and seroconversion rates were observed. Seroprotection rates after administration of the monovalent vaccine reached 93% and 98% in the adult groups, and 83.7% in the elderly group. After administration of the trivalent vaccine, seroprotection rates of 92.2% and 81.3% were obtained respectively in the adult and the elderly groups. No related serious adverse events and no safety signals were detected either with the monovalent or trivalent vaccine. CONCLUSION: Comparable immunogenicity profiles were observed in three clinical trials of the pandemic A(H1N1) 2009 strain when formulated either as a monovalent or as a component of a seasonal trivalent vaccine.

Genetic epidemiology of dengue viruses in phase III trials of the CYD tetravalent dengue vaccine and implications for efficacy.

This study defined the genetic epidemiology of dengue viruses (DENV) in two pivotal phase III trials of the tetravalent dengue vaccine, CYD-TDV, and thereby enabled virus genotype-specific estimates of vaccine efficacy (VE). Envelope gene sequences (n = 661) from 11 DENV genotypes in 10 endemic countries provided a contemporaneous global snapshot of DENV population genetics and revealed high amino acid identity between the E genes of vaccine strains and wild-type viruses from trial participants, including at epitope sites targeted by virus neutralising human monoclonal antibodies. Post-hoc analysis of all CYD14/15 trial participants revealed a statistically significant genotype-level VE association within DENV-4, where efficacy was lowest against genotype I. In subgroup analysis of trial participants age 9-16 years, VE estimates appeared more balanced within each serotype, suggesting that genotype-level heterogeneity may be limited in older children. Post-licensure surveillance is needed to monitor vaccine performance against the backdrop of DENV sequence diversity and evolution.

Pseudomonas aeruginosa otochondritis complicating localized cutaneous leishmaniasis: prevention of mutilation by early antibiotic therapy.

A patient with an ulcerated cutaneous leishmaniasis of the pinna had suppurative otochondritis after a first unsuccessful course of treatment with meglumine antimoniate. Although the Leishmania ulceration healed after a second course of meglumine antimoniate, and despite three oral dicloxacillin or pristinamycin courses, the otochondritis extended and an abscess developed. Pus from the abscess revealed a pure culture of Pseudomonas aeruginosa. Five days of oral ciprofloxacin plus rifampin led to a marked improvement. The P. aeruginosa isolate was sensitive to ciprofloxacin but fully resistant to rifampin. Healing with minimal mutilation was obtained at the end of a six-week course of multiple antibiotic therapy. Pseudomonas aeruginosa otochondritis was a co-factor of cartilage mutilation in this patient. Thus, infection with P. aeruginosa should be promptly treated when present in tender cutaneous or mucosal leishmaniasis lesions near cartilaginous areas.

Safety Overview of a Recombinant Live-Attenuated Tetravalent Dengue Vaccine: Pooled Analysis of Data from 18 Clinical Trials.

A recombinant live attenuated tetravalent dengue vaccine (CYD-TDV) has been shown to be efficacious in preventing virologically-confirmed dengue disease, severe dengue disease and dengue hospitalization in children aged 2-16 years in Asia and Latin America. We analyzed pooled safety data from 18 phase I, II and III clinical trials in which the dengue vaccine was administered to participants aged 2-60 years, including long-term safety follow-up in three efficacy trials. The participants were analyzed according to their age at enrollment. The percentage of participants aged 2-60 years reporting ≥1 solicited injection-site or systemic reactions was slightly higher in the CYD-TDV group than in the placebo group. The most common solicited injection-site reactions were pain. Headache and malaise were the most common solicited systemic reactions. In both groups 0.3% of participants discontinued for safety reasons. The most common unsolicited adverse events were injection-site reactions, gastrointestinal disorders, and infections. Reactogenicity did not increase with successive doses of CYD-TDV. The frequency and nature of SAEs occurring within 28 days of any dose were similar in the CYD-TDV and placebo groups and were common medical conditions that could be expected as a function of age. Baseline dengue virus serostatus did not appear to influence the safety profile. No vaccine-related anaphylactic reactions, neurotropic events or viscerotropic events were reported. In year 3 after dose 1, an imbalance for dengue hospitalization, including for severe dengue, observed in participants aged <9 years in the CYD-TDV group compared with the placebo group was not observed for participants aged ≥9 years. In Year 4, this imbalance in participants aged <9 years was less marked, giving an overall lower risk of dengue hospitalization or severe dengue from dose 1 to Year 4 in the CYD-TDV group. These results have contributed to the definition of the target population for vaccination (≥9 years old) for which CYD-TDV has a satisfactory safety profile. Long-term safety will continue to be monitored in the ongoing follow-up of efficacy trials. Safety and effectiveness in real-life settings will be assessed through post-licensure studies.

Lot-to-lot consistency of a tetravalent dengue vaccine in healthy adults in Australia: a randomised study.

BACKGROUND: The recombinant yellow fever-17D-dengue virus, live, attenuated, tetravalent dengue vaccine (CYD-TDV) has undergone extensive clinical trials. Here safety and consistency of immunogenicity of phase III manufacturing lots of CYD-TDV were evaluated and compared with a phase II lot and placebo in a dengue-naïve population. METHODS: Healthy 18-60 year-olds were randomly assigned in a 3:3:3:3:1 ratio to receive three subcutaneous doses of either CYD-TDV from any one of three phase III lots or a phase II lot, or placebo, respectively in a 0, 6, 12 month dosing schedule. Neutralising antibody geometric mean titres (PRNT50 GMTs) for each of the four dengue serotypes were compared in sera collected 28 days after the third vaccination-equivalence among lots was demonstrated if the lower and upper limits of the two-sided 95% CIs of the GMT ratio were ≥0.5 and ≤2.0, respectively. RESULTS: 712 participants received vaccine or placebo and 614 (86%) completed the study; 17 (2.4%) participants withdrew after adverse events. Equivalence of phase III lots was demonstrated for 11 of 12 pairwise comparisons. One of three comparisons for serotype 2 was not statistically equivalent. GMTs for serotype 2 in phase III lots were close to each other (65.9, 44.1 and 58.1, respectively). CONCLUSIONS: Phase III lots can be produced in a consistent manner with predictable immune response and acceptable safety profile similar to previously characterised phase II lots. The phase III lots may be considered as not clinically different as statistical equivalence was shown for serotypes 1, 3 and 4 across the phase III lots. For serotype 2, although equivalence was not shown between two lots, the GMTs observed in the phase III lots were consistently higher than those for the phase II lot. As such, in our view, biological equivalence for all serotypes was demonstrated.

Safety and immunogenicity of yellow fever 17D vaccine in adults receiving systemic corticosteroid therapy: an observational cohort study.

OBJECTIVE: To assess the safety and immunogenicity of live attenuated yellow fever (YF) 17D vaccine in adults receiving systemic corticosteroid therapy. METHODS: All adult travelers on systemic corticosteroid therapy who had received the YF17D vaccine in 24 French vaccination centers were prospectively enrolled and matched with healthy controls (1:2) on age and history of YF17D immunization. Safety was assessed in a self-administered standardized questionnaire within 10 days after immunization. YF-specific neutralizing antibody titers were measured 6 months after vaccination in patients receiving corticosteroids. RESULTS: Between July 2008 and February 2011, 102 vaccine recipients completed the safety study (34 receiving corticosteroids and 68 controls). The median age was 54.9 years (interquartile range [IQR] 45.1-60.3 years) and 45 participants had a history of previous YF17D immunization. The median time receiving corticosteroid therapy was 10 months (IQR 1-67 months) and the prednisone or equivalent dosage was 7 mg/day (IQR 5-20). Main indications were autoimmune diseases (n = 14), rheumatoid arthritis (n = 9), and upper respiratory tract infections (n = 8). No serious adverse event was reported; however, patients receiving corticosteroids reported more frequent moderate/severe local reactions than controls (12% and 2%, respectively; relative risk 8.0, 95% confidence interval 1.4-45.9). All subjects receiving corticosteroids who were tested (n = 20) had neutralizing antibody titers >10 after vaccination. CONCLUSION: After YF17D immunization, moderate/severe local reactions may be more frequent in patients receiving systemic corticosteroid therapy. Immunogenicity seems satisfactory. Large-scale studies are needed to confirm these results.

Safety and immunogenicity of SC599, an oral live attenuated Shigella dysenteriae type-1 vaccine in healthy volunteers: results of a Phase 2, randomized, double-blind placebo-controlled trial.

SC599 vaccine is a live Shigella dysenteriae 1 strain attenuated by deletion of invasion [icsA], iron chelation [ent, fep] and shiga toxin A subunit [stxA] genes. In a preliminary Phase 1 single dose prospective study, we showed that SC599 vaccine was well tolerated, and the maximum tolerable dose was greater than 10(8) CFU [Sadorge C, Ndiaye A, Beveridge N, Frazer S, Giemza R, Jolly N, et al. Phase 1 clinical trial of live attenuated Shigella dysenteriae type-1 DeltaicsA Deltaent Deltafep DeltastxA:HgR oral vaccine SC599 in healthy human adult volunteers. Vaccine 2008; 26(7):978-8]. In this Phase 2 trial, three groups of volunteers ingested a single dose of SC599 [10(5) CFU, n=38; 10(7) CFU, n=36] or placebo [n=37]. Both 10(5) and 10(7) CFU doses were immunogenic, inducing significant IgA and IgG LPS-specific ASCs and antibody responses, comparable in magnitude to those of other strains that prevented illness following experimental challenge. In the intention to treat analysis, 34.2% and 44.4% IgA ASC responders were detected in the 10(5) and 10(7) CFU groups respectively (p<0001 vs placebo for both groups), as well as 31.6% and 33.3% serum IgA responders (p<001 and p<0.001 vs placebo for 10(5) and 10(7) CFU groups, respectively). No difference between the two vaccine groups was observed. No stxB-specific antibody response was detected in the vaccines. SC599 excretion occurred in 23.7 and 30.6% of subjects in the 10(5) and 10(7) CFU groups, respectively. SC599 vaccine was well tolerated, and the reported adverse events were mainly digestive. These results indicate that a single oral immunization of SC599 vaccine elicits a significant circulating IgA ASC and serum antibody response that may confer protection against the most severe symptoms of Shigellosis in responders to the vaccine.