Immunogenicity and safety profiles of a new MAV/06 strain varicella vaccine in healthy children: A multinational,multicenter, randomized,double-blinded,active-controlled phase III study

Immunization is the most effective preventive strategy against varicella. While the Oka strain is commonly used for varicella vaccination worldwide, Korea widely uses the MAV/06 strain. A new live attenuated MAV/06 strain varicella vaccine (MG1111), which uses the new cell line Medical Research Council-5 for better viral propagation, was developed. MG1111 was approved by Korean health authorities. Here, we report the results of phase III, randomized, double–blind, multicenter study conducted in Korea and Thailand, which compared the immunogenicity and safety profiles of MG1111 versus the control vaccine, Varivax^TM. In total, 515 healthy children (12 month–12 years) were randomized 1:1 to receive either the MG1111 or control vaccine (MG1111: 258, Control: 257). The seroconversion rate (SCR) and geometric mean titer (GMT) were measured using the fluorescent antibody to membrane antigen (FAMA) test. The MG1111 group achieved a SCR of 97.9% (95% CI: 95.2–99.3) after vaccination. The lower limit of 95% CI for SCR difference (MG1111-Varivax^TM) was –4.0%, which was higher than the specified non-inferiority margin of –10%. Further, the GMT of the MG1111 increased from 2.0 to 74.2 (95% CI: 65.0–84.8) and the lower limits of the 95% CI for post–vaccination GMT ratios (MG1111/Varivax^TM) were 0.55 higher than the specified parameter of 0.5. Therefore, the MG1111 group was not statistically inferior to the control vaccine group in terms of SCR and GMT. Furthermore, the MG1111 and control vaccine groups were not significantly different in the percentage of participants showing adverse events—solicited, local, or systemic during 43-day period of observation and serious adverse events during 6 month of observation. The present results indicate that MG1111was not immunologically inferior to Varivax^TM, and safety profiles of MG1111 are similar to those of Varivax^TM.     

Immunogenicity and safety of the third booster dose of the inactivated Japanese encephalitis vaccine in Korean children: A prospective multicenter study

The immunization schedule for the inactivated Japanese encephalitis (JE) vaccine in Korea is a two-dose primary series at 12–24 months of age and three booster doses at 12 months after primary schedule and at 6 and 12 years of age. The aim of this study was to investigate immunogenicity and safety of the third booster dose of the inactivated JE vaccine, as well as the long-term immunogenicity of the second booster dose in Korean children. Healthy children aged 11–13 years, primed and given four doses of inactivated JE vaccines were included. All subjects received the third booster dose of the JE vaccine. Neutralizing antibody (NTAb) titers were assessed before and 4–6 weeks after vaccination using plaque reduction neutralization test (PRNT), and were considered to be protective at ≥ 1:10. Local and systemic adverse events were monitored for 4 weeks after vaccination. Before and after booster vaccination, all seroprotection rates were 100%. Geometric mean titer (GMT) showed a 6.05–fold increase, from 139.11 (95% CI: 110.76, 174.71) to 841.53 (95% CI, 714.25, 991.50). The local tolerability and systemic safety profiles were favorable, with no serious adverse events. In conclusion, the third booster dose of the inactivated JE vaccine was demonstrated to be safe and immunogenic in Korean children when administered according to the current immunization schedule.     

A Japanese study to assess immunogenicity and safety of a typhoid Vi polysaccharide vaccine

BackgroundAlthough typhoid fever is rare in Japan, imported cases have been reported occasionally in travelers returning from endemic areas. To achieve licensing of a typhoid Vi polysaccharide vaccine (Typhim Vi^®) and make it widely available in Japan, this study was conducted at the request of the Japanese Ministry of Health Labor and Welfare to assess the immunogenicity and safety of this vaccine when given as a single dose (the recommended schedule of administration) in a Japanese population.MethodsIn this multi-center, open-label, non-comparative, intervention study performed in Japan, 200 healthy volunteers (188 adults [≥18 years of age], 7 adolescents [12–17 years of age] and 5 children [2–11 years of age]) were administered Typhim Vi^®. Immunogenicity was assessed 28 days after vaccinations using an ELISA method of anti-Vi antibody detection. A 4-fold increase in anti-Vi titer was considered as the threshold for seroconversion for anti-Vi antibodies. Safety was assessed up to 28 days following vaccination.ResultsOverall, 92.0% (95% confidence interval [CI]: 87.3–95.4%) of participants achieved seroconversion 28 days after a single dose of typhoid Vi polysaccharide vaccine. GMTs of Vi antibody titers increased from 6.6 (95% CI: 5.8–7.4) prior to vaccination to 157.3 (95% CI: 135.1–183.2) on Day 28 after vaccination. The geometric mean of individual anti-Vi antibody titer ratios (Day 28/Day 0) was 23.9 (95% CI: 20.3–28.3). There were no immediate adverse events and no adverse events led to the discontinuation of participants from the study. Across all age groups, pain and myalgia were the most frequently reported injection site and systemic reactions, respectively. Most of these reactions were mild in intensity and resolved within 7 days.ConclusionsA single dose of typhoid Vi polysaccharide vaccine, Typhim Vi^®, demonstrated good safety and immunogenicity profile in a Japanese population.     

Immunogenicity and safety of Quadrivalent Influenza HA vaccine in Indonesian children: An open-labeled,bridging, clinical study

BackgroundInfluenza B (Yamagata/Victoria lineage) can cause severe forms of respiratory infection among the pediatric population as well as influenza A strains (H3N2/H1N1). Vaccination against all four strains is required to prevent infection and severe outcome. This study is the first study to assess the immunogenicity of Quadrivalent Influenza HA vaccine (QIV) and ascertain safety among children in Indonesia.MethodsThis is an open labeled, single arm, bridging clinical study involving unprimed healthy children 6–35 months of age (Group I) and 3–8 years of age (Group II). Subjects on both groups receiving two doses of QIV with a 28 days interval. Serology tests were performed on baseline and 28 days post-vaccination. Hemagglutination inhibition antibody titers were analyzed for Geometric Mean Titer (GMT), seroprotection, and seroconversion rates. Solicited reactions, unsolicited adverse events, and serious adverse events were observed up to 28 days post-vaccination.ResultsOut of 270 subjects enrolled, 269 subjects completed the study. Immunogenicity analysis were evaluated on 254 subjects. Seroprotection rates were ≥85% for all vaccine strains in both groups. Seroconversion of more than 4 folds for all strains occurred in both groups post-vaccination. In Group I, the increase of GMT for A/H1N1, A/H3N2, B/Texas, and B/Phuket was 12.5, 14.5, 8.2, and 6.4 folds, respectively. In Group II the increase of GMT for A/H1N1, A/H3N2, B/Texas, and B/Phuket was 14, 17, 10, and 8 folds, respectively. The majority of local adverse events (AEs) after the first and second immunizations were immediate injection-site pain (10.4% and 12.6%). The majority of systemic AEs after the first and second immunizations were delayed unsolicited AEs (14.8% and 14.9%). No vaccine-related serious adverse events or deaths were reported.ConclusionThe investigational QIV was immunogenic with an acceptable safety profile in children 6 months to 8 years of age.Clinical Trial registration: NCT03336593.     

Phase I,randomized, observer-blind,placebo-controlled studies to evaluate the safety,reactogenicity and immunogenicity of an investigational non-typeable Haemophilus influenzae (NTHi) protein vaccine in adults

BackgroundNon-typeable Haemophilus influenzae (NTHi) is a major cause of various respiratory diseases. The development of an effective vaccine against NTHi mandates new approaches beyond conjugated vaccines as this opportunistic bacterium is non-encapsulated. Here we report on the safety, reactogenicity and immunogenicity of a multi-component investigational vaccine based on three conserved surface proteins from NTHi (proteins D [PD], E [PE] and Pilin A [PilA]) in two observer-blind phase I studies.MethodsIn the first study (NCT01657526), 48 healthy 18–40 year-olds received two vaccine formulations (10 or 30 μg of each antigen [PD and a fusion protein PE-PilA]) or saline placebo at months 0 and 2. In the second study (NCT01678677), 270 50–70 year-olds, current or former smokers, received eight vaccine formulations (10 or 30 μg antigen/dose non-adjuvanted or adjuvanted with alum, AS01_E or AS04_C) or saline placebo at months 0, 2 and 6 (plain and alum-adjuvanted groups) and at months 0 and 2 (AS-adjuvanted groups). Solicited and unsolicited adverse events (AEs) were recorded for 7 and 30 days post-vaccination, respectively; potential immune-mediated diseases (pIMDs) and serious AEs (SAEs) throughout the studies. Humoral and antigen-specific T-cell immunity (in study 2 only) responses were assessed up to 12 months post-vaccination.ResultsObserved reactogenicity was highest in the AS-adjuvanted groups but no safety concerns were identified with any of the NTHi vaccine formulations. One fatal SAE (cardiac arrest) not considered related to vaccination, and one pIMD (non-serious psoriasis) in the Placebo group, were reported post-dose 3 in Study 2. All formulations generated a robust antibody response while the AS01-adjuvanted formulations produced the highest humoral and cellular immune responses.ConclusionThis study confirms that the NTHi vaccine formulations had an acceptable reactogenicity and safety profile and were immunogenic in adults. These results justify further clinical development of this NTHi vaccine candidate.     

Immunogenicity and safety of a modified three-dose priming and booster schedule for the Hantaan virus vaccine (Hantavax): A multi-center phase III clinical trial in healthy adults

BackgroundHemorrhagic fever with renal syndrome is a serious health problem in Eurasian countries. This study aimed to evaluate the immunogenicity and safety of formalin-inactivated Hantaan virus vaccine (Hantavax®) with a 3 + 1 vaccination schedule.MethodsA phase III, multi-center clinical trial was conducted to evaluate the immunogenicity and safety of Hantavax® (three primary doses and a booster dose schedule at 0, 1, 2 and 13 months) among healthy adults. Immune responses were assessed using the plaque reduction neutralizing antibody test (PRNT) and immunofluorescent antibody assay (IFA). Systemic and local adverse events were assessed.ResultsA total of 320 healthy subjects aged ≥19 years were enrolled. Following three primary doses of Hantavax®, the seroconversion rate was 80.97% and 92.81% by PRNT and IFA, respectively. With booster administration, seropositive rates were 67.47% and 95.68% at one-month post-vaccination according to PRNT and IFA, respectively. Solicited local and systemic adverse events were reported in 30.50–42.81% and 16.67–33.75% during the three primary dose vaccination, while those were reported 36.57% and 21.36% after the booster doses. Both local and systemic adverse events did not increase with repeated vaccinations.ConclusionHantavax® showed a high seroconversion rate after the three-dose priming, and additional dose administration with 11-month interval induced good booster effects. (ClinicalTrials.gov Identifier: NCT02553837).     

Evaluation of a recombinant five-antigen Staphylococcus aureus vaccine: The randomized,single-centre phase 1a/1b clinical trials

BackgroundStaphylococcus aureus is an important pathogen that causes hospital and community infections. To control Staphylococcus aureus infection and reduce the usage of antibiotics, we evaluated the safety and immunogenicity of a recombinant five-antigen Staphylococcus aureus vaccine (rFSAV) in healthy adults.MethodsWe conducted a randomized, double-blind, placebo-controlled phase 1a study and a randomized, open-label phase 1b study. In phase 1a, we randomly allocated 144 healthy participants in a ratio of 1:1:1:1 to receive the low-(60 μg), middle-(120 μg), and high-dose (240 μg) vaccine or placebo at day 0, 3, 7 and 14. In phase 1b, 144 healthy participants were randomly allocated at a ratio of 1:1:1:1 to receive 0–3–7, 0/0–7, 0/0–3–7, 0/0–7–14 regimens to estimate the optimal strategy. The primary study endpoint was the incidence of solicited adverse events post-vaccination. The immunogenicity endpoints included the level of specific antibodies to five antigens after vaccination, as well as the cellular immune responses and functional antibodies.ResultsThere were 31 (86%), 30 (83%), and 32 (89%) of 36 participants in the low-, middle-, and high-dose group reported solicited adverse events, respectively, most of the adverse events were mild or moderate. In phase 1b, the dose-adjusted rFSAV (90 μg) showed a better safety profile in the four immune procedures, and no vaccine-related serious adverse events were reported. The antigen-specific binding antibodies started to increase at day 7 and reached the peak around day 14 to 21. The cellular immune responses and functional antibodies also were substantially above background levels.ConclusionsrFSAV is safe, well tolerated in healthy adults, elicits rapid and robust specific humoral and cellular immune responses with unconventional immunization procedure in phase 1a and 1b. It deserves to be noted and further explored.Clinical Trials Registration: NCT02804711 and NCT03966040.     

Immunogenicity and safety of MenACWY-TT,a meningococcal conjugate vaccine,co-administered with routine childhood vaccine in healthy infants: A phase III,randomized study

BackgroundInvasive meningococcal disease has a high burden in young children, particularly during infancy. We investigated the immunogenicity and safety of a quadrivalent meningococcal conjugated vaccine (MenACWY-TT) co-administered with routine vaccines in healthy infants.MethodsIn this phase IIIb study (NCT01340898) conducted in 2 centers in Lebanon and Mexico, 750 infants were randomized (2:1:1) to receive MenACWY-TT according to 3 schedules: 3+1 (at ages 2, 4, 6 and 15–18 months; group ACWY3+1); 1+1 (at 6 and 15–18 months; group ACWY1+1) or single-dose at 15–18 months (group ACWY1). All infants received PHiD-CV and DTPa-IPV/Hib at ages 2, 4, 6, 15–18 months. Immune responses to MenACWY-TT were assessed by rSBA and hSBA at 7 months (groups ACWY3+1, ACWY1+1) and pre- and post-vaccination at 15–18 months of age (all groups). Immune responses to co-administered vaccines, reactogenicity and safety were also evaluated.ResultsImmunogenicity of MenACWY-TT at 1 month post-primary vaccination was demonstrated in group ACWY3+1: the lower limit of the 95% confidence interval for the percentage of infants with rSBA titers ≥8 was >80% for each serogroup. At 7 months of age, ≥93.9% of MenACWY-TT-primed infants had rSBA titers ≥8. Post-MenACWY-TT vaccination at age 15–18 months, ≥96.3% of participants in all groups had rSBA titers ≥8, regardless of the number of doses received previously. The percentage of infants with hSBA titers ≥4 were ≥87.2% and ≥89.7% at post-primary and booster/single-dose vaccination, respectively. Immune responses to PHiD-CV and DTPa-IPV/Hib did not seem impacted by co-administration with MenACWY-TT in infancy. The incidence of all adverse events was similar among groups. Serious adverse events were reported for 63/750 children in all groups; none were considered vaccine-related by investigators.ConclusionPrimary vaccination with 3 or 1 dose(s) of MenACWY-TT when co-administered with routine pediatric vaccines in infants is immunogenic and well-tolerated.     

Lot-to-lot consistency,safety and immunogenicity of 3 lots of Haemophilus influenzae type b conjugate vaccine: results from a phase III randomized,multicenter study in infants

BackgroundVaccination against Haemophilus influenzae type b (Hib) is included in routine pediatric immunization schedule in the United States. Previous vaccine shortages have created the need for additional options for Hib vaccination.MethodsThis phase III, randomized, multi-centered study (NCT01000974) evaluated the safety and immunogenicity of a monovalent tetanus toxoid-conjugate Hib vaccine (Hib-TT) compared to a monovalent (Hib-TT control) and a combination Hib-TT vaccine. We hierarchically assessed lot-to-lot consistency of 3 Hib-TT lots and non-inferiority of Hib-TT to Hib-TT control. We co-administered routine pediatric vaccines with Hib-TT vaccines at 2, 4, 6 months (primary vaccination) and 15–18 months of age (booster vaccination). We recorded adverse events (AEs) for 4 (solicited) and 31 days (unsolicited) post-vaccination and serious AEs (SAEs) throughout the study.ResultsOf 4009 enrolled children, 3086 completed booster phase. Lot-to-lot consistency was not demonstrated. The study met statistical criteria for non-inferiority of Hib-TT to Hib-TT control in terms of immune responses to Hib and co-administered vaccines’ antigens, but not in terms of participants achieving post-primary vaccination anti-PRP levels ≥1 µg/mL. Because of the hierarchical nature of the objectives, non-inferiority could not be established. In all groups, 92.5–96.7% and 99.6–100% of participants achieved anti-PRP levels ≥0.15 µg/mL, while 78.3–89.8% and 97.9–99.1% had anti-PRP levels ≥1 µg/mL, post-primary and post-booster vaccination, respectively. Immune responses to co-administered vaccines and reported incidence of AEs were comparable among groups. We recorded SAEs for 107/2963 (3.6%), 24/520 (4.6%), and 21/520 (4.0%) children post-primary vaccination, and 29/2337 (1.2%), 4/435 (0.9%), and 2/400 (0.5%) children post-booster vaccination with Hib-TT, Hib-TT control and combination Hib-TT vaccine, respectively; 6/5330 (0.1%) SAEs in the Hib-TT groups were considered vaccine-related.ConclusionHib-TT induced seroprotective antibody concentrations in the majority of participants and was well-tolerated when co-administered with routine pediatric vaccines according to a 3 + 1 schedule.     

The safety and immunogenicity of a recombinant five-antigen Staphylococcus aureus vaccine among patients undergoing elective surgery for closed fractures: A randomized,double-blind,placebo-controlled,multicenter phase 2 clinical trial

BackgroundVaccines are urgently required to control Staphylococcus aureus hospital and community infections and reduce the use of antibiotics. Here, we report the safety and immunogenicity of a recombinant five-antigen Staphylococcus aureus vaccine (rFSAV) in patients undergoing elective surgery for closed fractures.MethodsA randomized, double-blind, placebo-controlled, multicenter phase 2 clinical trial was carried out in 10 clinical research centers in China. Patients undergoing elective surgery for closed fractures, aged 18–70 years, were randomly allocated at a ratio of 1:1 to receive the rFSAV or placebo at a regimen of two doses on day 0 and another dose on day 7. All participants and investigators remained blinded during the study period. The safety endpoint was the incidence of adverse events within 180 days. The immunogenicity endpoints included the level of specific antibodies to five antigens after vaccination, as well as opsonophagocytic antibodies.ResultsA total of 348 eligible participants were randomized to the rFSAV (n = 174) and placebo (n = 174) groups. No grade 3 local adverse events occurred. There was no significant difference in the incidence of overall systemic adverse events between the experimental (40.24 %) and control groups (33.72 %) within 180 days after the first immunization. The antigen-specific binding antibodies started to increase at days 7 and reached their peaks at 10–14 days after the first immunization. The rapid and potent opsonophagocytic antibodies were also substantially above the background levels.ConclusionsrFSAV is safe and well-tolerated in patients undergoing elective surgery for closed fractures. It elicited rapid and robust specific humoral immune responses using the perioperative immunization procedure. These results provide evidence for further clinical trials to confirm the vaccine efficacy.China's Drug Clinical Trials Registration and Information Publicity Platform registration number: CTR20181788. WHO International Clinical Trial Registry Platform identifier: ChiCTR2200066259.     

Safety,immunogenicity, and lot-to-lot consistency of a quadrivalent inactivated influenza vaccine in children,adolescents, and adults: A randomized,controlled, phase III trial

BackgroundInactivated quadrivalent influenza vaccine (IIV4) containing two influenza A strains and one strain from each B lineage (Yamagata and Victoria) may offer broader protection against seasonal influenza than inactivated trivalent influenza vaccine (IIV3), containing a single B strain. This study examined the safety, immunogenicity, and lot consistency of an IIV4 candidate.MethodsThis phase III, randomized, controlled, multicenter trial in children/adolescents (9 through 17 years) and adults (18 through 60 years) was conducted in Australia and in the Philippines in 2012. The study was double-blind for IIV4 lots and open-label for IIV4 vs IIV3. Children/adolescents were randomized 2:2:2:1 and adults 10:10:10:1 to receive one of three lots of IIV4 or licensed IIV3. Safety data were collected for up to 6 months post-vaccination. Hemagglutination inhibition and seroneutralization antibody titers were assessed pre-vaccination and 21 days post-vaccination.Results1648 adults and 329 children/adolescents received IIV4, and 56 adults and 55 children/adolescents received IIV3. Solicited reactions, unsolicited adverse events, and serious adverse events were similar for IIV3 and IIV4 recipients in both age groups. Injection-site pain, headache, malaise, and myalgia were the most frequently reported solicited reactions, most of which were mild and resolved within 3 days. No vaccine-related serious adverse events or deaths were reported. Post-vaccination antibody responses, seroconversion rates, and seroprotection rates for the 3 strains common to both vaccines were comparable for IIV3 and IIV4 in both age groups. Antibody responses to IIV4 were equivalent among vaccine lots and comparable between age groups for each of the 4 strains. IIV4 met all European Medicines Agency immunogenicity criteria for adults for all 4 strains.ConclusionsIn both age groups, IIV4 was well tolerated and caused no safety concerns, induced robust antibody responses to all 4 influenza strains, and met all EMA immunogenicity criteria for adults.Clinical trial registry numberNCT01481454.     

Safety and immunogenicity of a candidate bioconjugate vaccine against Shigella dysenteriae type 1 administered to healthy adults: A single blind,partially randomized Phase I study

BackgroundShigellae cause severe disease in endemic countries, especially in children. Several efficacy trials have been conducted with candidate vaccines against Shigellae, but the lack of protection, the safety concerns, or manufacturing challenges hindered successful market approval. Conjugated vaccines have been shown to be safe and effective for different pathogens (i.e., Neisseria meningitidis, Shigella pneumonia, Haemophilus influenzae). The bio-conjugation technology, exploited here for the Shigella dysenteriae candidate vaccine, offers a novel and potentially simpler way to develop and produce vaccines against one of the major causes of morbidity and mortality in developing countries.MethodsA novel S. dysenteriae bioconjugate vaccine (GVXN SD133) made of the polysaccharide component of the Shigella O1 lipopolysaccharide, conjugated to the exotoxin protein A of Pseudomonas aeruginosa (EPA), was evaluated for immunogenicity and safety in healthy adults in a single blind, partially randomized Phase I study. Forty subjects (10 in each dose group; 2 μg or 10 μg with or without aluminium adjuvant) received two injections 60 days apart and were followed-up for 150 days.ResultsBoth doses and formulations were well tolerated; the safety and reactogenicity profiles were consistent with that of other conjugated vaccines, adjuvanted or not, independent of the dose and the number of injections. The GVXN SD133 vaccine elicited statistically significant O1 specific humoral responses at all time points in all vaccination groups. Between-group comparisons did not show statistically significant differences in geometric mean titers of immunoglobulin G and A at any post-vaccination time point.ConclusionsThis study demonstrated that the GVXN SD133 vaccine has a satisfactory safety profile. It elicited a significant humoral response to Shigella O1 polysaccharides at all doses tested. The protein carrier also elicited functional antibodies, showing the technology's advantages in preserving both sugar and conjugated protein epitopes. This trial is registered at ClinicalTrials.gov (NCT01069471).     

Immunogenicity and safety of a quadrivalent inactivated influenza vaccine in healthy subjects aged 3 to 17 years old: A phase III,open label,single-arm study

BackgroundQuadrivalent influenza vaccines are particularly valuable during seasons in which a mismatch occurs between the predicted influenza B lineage for the trivalent influenza vaccine and the circulating strain. This study evaluated the immunogenicity and safety of a quadrivalent inactivated influenza vaccine AdimFlu-S manufactured in Taiwan for the 2016–2017 influenza season in healthy children.MethodsA total of 174 healthy children aged 3 to 17 years old were separated into 3 groups (Group A: 3–8 years old, vaccine naïve; Group B: 3–8 years old, vaccine non-naïve; Group C: 9–17 years old, any vaccine status). Sera was collected pre and post vaccination for each participant. A hemagglutination inhibition (HAI) assay was utilized to calculate geometric mean titer (GMT), seroprotection rate, and seroconversion rate.ResultsAll enrolled participants completed the study. For the four vaccine strains four weeks after the last vaccination, geometric mean titer ratios (GMTRs) were between 2.9 and 20.9, seroconversion rates were between 42.9% and 90.9%, and seroprotection rates were all above 96.4%. This achieved all immunogenicity endpoints and fulfilled the criteria of the European Medical Agency’s Committee for Medicinal Products for Human Use (CHMP). No serious adverse events (AEs) were reported during the follow-up period of 6 months.ConclusionThis quadrivalent influenza vaccine is demonstrated to be well tolerated and displays robust immunogenicity for each influenza strain. This could potentially improve protection against the antigenically distinct B/Yamagata and B/Victoria lineages.     

Immunogenicity and safety of a novel recombinant protective antigen anthrax vaccine (GC1109), a randomized,single-blind,placebo controlled phase II clinical study

BackgroundThe demand on effective and safe anthrax vaccine is increasing as a part of the preparedness for possible bioterrorism in the future. We performed a randomized, single-blind, placebo controlled phase II clinical study to evaluate the immunogenicity and safety of a novel recombinant protective antigen (rPA) anthrax vaccine, GC1109, in healthy adult volunteers.MethodsParticipants were randomized to experiment groups (0.3 mL, 0.5 mL, and 1.0 mL of GC1109) or placebo group (normal saline 0.5 mL) in 2:2:2:1 ratio. They received respective vaccines intramuscularly at 0, 4 and 8 weeks. Immunogenicity was evaluated by seroconversion rate and geometric mean titer (GMT) of lethal toxin neutralizing assay (TNA) and anti-PA IgG by ELISA. Safety was assessed by laboratory tests, and solicited and unsolicited adverse events on diary cards.Results30, 29, 30 participants were randomized to 0.3, 0.5, and 1.0 mL of GC1109 groups, respectively, while 15 to placebo group. 92 participants received all three doses. In per-protocol analysis, TNA GMTs at week 12 were 296.5, 285.2, and 433.2 in the three groups, respectively. Seroconversion rates measured by ELISA were 100% at week 12 in the three groups. Local and systemic vaccine-related adverse events were frequent; however, most of them were mild, and no serious events were observed.ConclusionsA new rPA anthrax vaccine GC1109 was immunogenic after three doses of intramuscular administration, and was well-tolerated.     

Safety and tolerability of a cell culture derived trivalent subunit inactivated influenza vaccine administered to healthy children and adolescents: A Phase III,randomized, multicenter,observer-blind study

BackgroundCell culture-derived inactivated influenza vaccines (TIVc) are necessary for scale and predictability of production to meet global demand. This study compared the safety and tolerability of TIVc with an egg-derived trivalent influenza vaccine (TIVf) in 4–17 yearolds.MethodsA Phase 3 observer blind, multicenter study enrolled 2055 healthy participants randomized 2:1 to receive either TIVc or TIVf, respectively (1372 TIVc and 683 TIVf evaluable subjects). Participants received one dose each on Days 1 and 28 (4–8 year-olds not previously vaccinated [NPV]) or one dose on Day 1 (4–8 and 9–17 yearolds previously vaccinated [PV]). Solicited adverse events (AEs) occurring within 7 days after each vaccination were assessed; participants were followed up for 6 months after their last dose for safety.ResultsMost solicited and unsolicited AEs were mild to moderate with <1% in the severe category. No withdrawals due to AEs, deaths or vaccine-related SAEs were reported. TIVc and TIVf were similar in percentages of participants reporting solicited reactions in 4–8 years NPV group after the 1st dose: local reactions, TIVc: 48%, TIVf: 43%; systemic reactions, TIVc: 34%, TIVf: 32%; percentages were lower following the 2nd dose in TIVc; local reactions: TIVc: 40%; TIVf: 43%; systemic reactions: TIVc: 21%; TIVf: 22%. In 4–17 years PV group, solicited reactions were lower following TIVf, local reactions: TIVc: 53%; TIVf: 43%; systemic reactions: TIVc: 37%, TIVf: 30%. Injection-site pain was the most common solicited reaction, and was similar following TIVc and TIVf in 4–8 yearolds (TIVc: 56%; TIVf: 55%), and lower following TIVf in 9–17 years group (TIVc: 52%; TIVf: 42%). Reporting of unsolicited AEs was similar for TIVc and TIVf across the two age groups.ConclusionTIVc was well tolerated and had a safety and reactogenicity profile similar to that of TIVf in healthy 4–17 yearolds (NCT01857206).     

Results from a preclinical study in rodents and a Phase 1/2, randomized,double-blind,placebo-controlled,parallel-group study of COVID-19 vaccine S-268019-a in Japanese adults

BackgroundIn early 2020, developing vaccines was an urgent need for preventing COVID-19 from a contingency perspective.MethodsS-268019-a is a recombinant protein-based vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), comprising a modified recombinant spike protein antigen adjuvanted with agatolimod sodium, a Toll-like receptor-9 agonist. In the preclinical phase, it was administered intramuscularly twice at a 2-week interval in 7-week-old mice. Immunogenicity was assessed, and the mice were challenged intranasally with mouse-adapted SARS-CoV-2 at 2 and 8 weeks, respectively, after the second immunization. After confirming the preclinical effect, a Phase 1/2, randomized, parallel-group clinical study was conducted in healthy adults (aged 20–64 years). All participants received 2 intramuscular injections at various combinations of the antigen and the adjuvant (S-910823/agatolimod sodium, in μg: 12.5/250, 25/250, 50/250, 25/500, 50/500, 100/500, 10/500, 100/100, 200/1000) or placebo (saline) in an equivalent volume at a 3-week interval and were followed up until Day 50 in this interim analysis.ResultsIn the preclinical studies, S-268019-a was safe and elicited robust immunoglobulin G (IgG) and neutralizing antibody responses in mice. When challenged with SARS-CoV-2, all S-268019-a-treated mice survived and maintained weight until 10 days, whereas all placebo- or adjuvant-treated (without antigen) mice died within 6 days. In the Phase 1/2 trial, although S-268019-a was well tolerated in adult participants, was safe up to Day 50, and elicited robust anti-spike protein IgG antibodies, it did not elicit sufficient neutralizing antibody levels.ConclusionsThe S-268019-a vaccine was not sufficiently immunogenic in Japanese adults despite robust immunogenicity and efficacy in mice. Our results exemplify the innate challenges in translating preclinical data in animals to clinical trials, and highlight the need for continued research to overcome such barriers. (jRCT2051200092)     

Safety and immunogenicity of inactivated poliovirus vaccine made from Sabin strains: A phase II,randomized, dose-finding trial

BackgroundIn order to completely eradicate polio caused by wild poliovirus infection as well as vaccine-associated paralytic polio (VAPP), Sabin inactivated poliovirus vaccine (sIPV) should be developed to meet the requirements for biosafety and affordable strategy in the developing countries.MethodA randomized, double-blinded clinical trial was conducted to compare the immunogenicity and safety among infants aged 2 months (60–90 days) receiving five different vaccination regimens: the test groups (A, B, and C) received three doses of sIPV with high, medium, and low D antigen content, respectively, on the month 0, 1, 2 schedule; two control groups (D and E) received three doses of conventional IPV (cIPV) or sIPV (CAMS), respectively, on the same schedule as that of test groups. Serum samples were collected immediately before the 1st dose and 30 days after the 3rd dose vaccination to assess the immunogenicity. Adverse events occurring within 30 days after each dose were collected to assess the safety.ResultsAfter three doses, seroconversion rates in groups A–E were 100%, 98.2%, 100%, 100%, and 100%, respectively, for type 1; 99.1%, 100%, 98.1%, 100%, and 97.1%, respectively, for type 2; and 100%, 100%, 100%, 100%, and 99.0%, respectively, for type 3. The seropositive rates (≥1:8) of groups A–E for all types were nearly 100%. The GMTs in the target dose group (group B) were 4635, 342, and 2218 for type 1–3, respectively. The most common injection-site and systemic adverse reactions were swelling and fever respectively. The swelling (4.2%, P = 0.0075) and fever (58.3%, P = 0.0188) frequency of group A were statistically significantly higher than any other groups.ConclusionThe test sIPV generally demonstrated good safety and immunogenicity. The medium-D antigen dose would be a preferred choice for the further phase III clinical trial in consideration of its high immunogenicity for all serotypes and the satisfying tolerance.Clinical Trials Registration. NCT02985320.     

Post-licensure,phase IV,safety study of a live attenuated Japanese encephalitis recombinant vaccine in children in Thailand

BackgroundJapanese encephalitis is a mosquito-borne viral disease endemic in most countries in Asia. A recombinant live, attenuated Japanese encephalitis virus vaccine, JE-CV, is licensed in 14 countries, including Thailand, for the prevention of Japanese encephalitis in adults and children.MethodsThis was a prospective, phase IV, open-label, multicentre, safety study of JE-CV conducted from November 2013 to April 2015, to evaluate rare serious adverse events (AEs). JE-CV was administered to 10,000 healthy children aged 9 months to <5 years in Thailand as a primary (Group 1) or booster (Group 2) vaccination. Serious AEs (SAEs), including AEs of special interest, up to 60 days after administration were evaluated. Immediate Grade 3 systemic AEs up to 30 min after JE-CV administration were also described.ResultsThe median age of participants was 1.1 years in Group 1 and 3.8 years in Group 2. SAEs were reported in 204 (3.0%) participants in Group 1 and 59 (1.9%) participants in Group 2. Among a total of 294 SAEs in 263 participants, only three events occurring in two participants were considered related to vaccination. All three cases were moderate urticaria, none of which met the definition of AEs of special interest for hypersensitivity. AEs of special interest were reported in 28 (0.4%) participants in Group 1 and 4 (0.1%) participants in Group 2; none were considered related to vaccination. Febrile convulsion was the most frequently reported AE of special interest: 25 (0.4%) participants in Group 1; and 2 (<0.1%) in Group 2. There were no cases of Japanese encephalitis reported. No Grade 3 immediate systemic AEs were reported after any JE-CV vaccination.ConclusionsOur study did not identify any new safety concerns with JE-CV and confirms its good safety profile.This study was registered on www.clinicaltrials.gov (NCT01981967; Universal Trial Number: U1111-1127-7052).     

Immunogenicity of a bivalent virus-like particle norovirus vaccine in children from 1 to 8 years of age: A phase 2 randomized,double-blind study

BackgroundYoung children can suffer severe consequences of norovirus gastroenteritis. We performed a dose-finding study of a bivalent virus-like particle (VLP) vaccine candidate (TAK-214) in healthy 1–8-year-old children.MethodsIn this phase 2 study two age cohorts (1–3 and 4–8 years of age inclusive, N = 120 per cohort) of children enrolled from Finland, Panama and Colombia were initially randomized 1:1:1:1 to four groups which were further split into two equal subgroups, to receive one or two intramuscular doses of four TAK-214 formulations containing 15/15, 15/50, 50/50 or 50/150 μg of GI.1/GII.4c genotype VLPs and 0.5 mg Al(OH)₃ at 28 days interval. ELISA Pan-Ig and histoblood group antigen-blocking (HBGA) antibodies against each VLP were measured on days 1, 29, 57 and 210. Parents/guardians recorded solicited local and systemic adverse events (AE) and any unsolicited or serious AEs (SAE).ResultsAll formulations were well-tolerated across both age cohorts and dosage groups with no vaccine-related SAEs reported. Solicited AEs were mostly mild-to-moderate, resolved quickly, and did not increase after the second dose. Pan-Ig and HBGA responses induced after one dose were only slightly increased by the second dose. Across dose groups at Day 29 after one dose GI.1 Pan Ig seroresponse rates (SRR) were 82–97% and 81–96% and GII.4c SRR were 79–97% and 80–91% in 1–3 and 4–8 year-olds, respectively. Respective rates were to 92–93% and 73–92% for GI.1, and 77–100% and 62–83% for GII.4c at Day 57 following two doses. HBGA responses had similar profiles. Both Pan Ig and HBGA geometric mean titers persisted above baseline up to Day 210.ConclusionsAll dosages of TAK-214 displayed acceptable reactogenicity in 1–8-year-old children and induced robust, durable immune responses after one dose which are further increased after two doses.