MeNZB: a safe and highly immunogenic tailor-made vaccine against the New Zealand Neisseria meningitidis serogroup B disease epidemic strain

Clinical studies have been conducted in New Zealand evaluating the safety and immunogenicity of an outer membrane vesicle (OMV) vaccine, MeNZB, developed to control epidemic disease caused by group B meningococci, subtype P1.7b,4. MeNZB, administered in a three-dose regimen, was well tolerated and induced a seroresponse, defined as a four-fold rise (> or =titre 8) in serum bactericidal antibodies against the vaccine strain 4-6 weeks after the third vaccination, in 96% (95% confidence interval (CI): 79-100%) of adults, 76% (95% CI: 72-80%) of children, 75% (95% CI: 69-80%) of toddlers and 74% (95% CI: 67-80%) of infants receiving MeNZB. In conclusion, these findings suggest that MeNZB is safe and is likely to confer protection against systemic group B meningococcal disease caused by the epidemic strain.     

Immunogenicity and reactogenicity of a group C meningococcal conjugate vaccine compared with a group A+C meningococcal polysaccharide vaccine in adolescents in a randomised observer-blind controlled trial

This study evaluated the immunogenicity and reactogenicity of a group C meningococcal conjugate vaccine (MenC) compared with a group A+C meningococcal polysaccharide vaccine (MenPS) in healthy adolescents. Subjects were randomised to receive one dose of either MenC (n=92) or MenPS (n=90). Group C meningococcal IgG antibody concentrations and bactericidal titres were higher in the MenC group than the MenPS group at 1 month (22.8 U/ml vs 4.0 U/ml, p<0.001, and 87 vs 20, p<0.001, respectively) and 12 months (6.1 U/ml vs 3.0 U/ml, p<0.001, and 81.3 vs 20.2, p<0.001, respectively). No differences in post immunisation reaction rates were noted between the two vaccinated groups. This study demonstrated the safety and enhanced immunogenicity of the candidate meningococcal conjugate vaccine as compared with the licensed polysaccharide vaccine in adolescents.     

The concept of "tailor-made", protein-based, outer membrane vesicle vaccines against meningococcal disease

Protein-based, outer membrane vesicle (OMV) vaccines have previously proven to be efficacious against serogroup B meningococcal disease in Norway and Cuba. Currently, a public health intervention is going on in order to control a serogroup B epidemic in New Zealand. The scale-up and standardization of vaccine production required for controlling the New Zealand epidemic has allowed the establishment of large-scale GMP manufacturing for OMV vaccines. The outcome of this will be licensing of the vaccine in New Zealand and possibly other countries. The availability of licensed OMV vaccines raises the question of whether such vaccines may provide the opportunity to control other outbreaks and epidemics. For instance, such a vaccine could control a localised outbreak of group B meningococci in Normandy, France. "Tailor-made" vaccines, focusing on the sub-capsular antigens may also be considered for use in sub-Saharan Africa for the prevention of the recurrent outbreaks by serogroups A and W135 meningococci. This assumption is based on the epidemiological observation that meningococcal outbreaks in Africa are clonal and are strikingly stable regarding their phenotypic characteristics.     

Safety and immunogenicity of a new Neisseria meningitidis serogroup C-tetanus toxoid conjugate vaccine in healthy adults.

We evaluated the safety and immunogenicity of a single dose of a new serogroup C O-deacetylated meningococcal polysaccharide-tetanus toxoid conjugate vaccine in 30 healthy adult volunteers. The vaccine was well tolerated with no serious adverse events and minimal local reactions and systemic symptoms. All subjects developed a fourfold or greater increase in serum bactericidal antibody (SBA) to serogroup C meningococcus. SBA geometric mean titre increased from 11 to 3649 (p<0.001). Serogroup C-specific IgG levels increased postvaccination from 0.65 to 17.02 microg/ml (p<0.001). Bactericidal titres pre- and postimmunisation showed significant correlation with serogroup C-specific IgG (r(2)=0.693). Antibody levels fell by 6 months postvaccination, however, meningococcal C IgG avidity increased indicating the successful induction of a T-cell-dependent antibody response. Conclusion: meningococcal C-tetanus toxoid conjugate vaccine is immunogenic and well tolerated in healthy adults.     

Effectiveness of a vaccination programme for an epidemic of meningococcal B in New Zealand

New Zealand has experienced a prolonged epidemic of meningococcal B disease since 1991. The epidemic has waned significantly since its most recent peak in 2001. A strain-specific vaccine, MeNZB, was introduced to control the epidemic in 2004, achieving 81% coverage of people under the age of 20. The vaccine was rolled out in a staged manner allowing the comparison of disease rates in vaccinated and unvaccinated individuals in each year.Vaccine effectiveness in people aged under 20 years is estimated using a Poisson regression model in the years 2001-2008, including adjustments for year, season, age, ethnicity, region and socioeconomic status. Further analyses investigate the dose response relationship, waning of the vaccine effect after one year, and cross-protection against other strains of meningococcal disease.The primary analysis estimates MeNZB vaccine effectiveness to be 77% (95% CI 62-85) after 3 doses and a mean follow-up time of 3.2 years. There is evidence for a protective effect after 2 doses 47% (95% CI 16-67), and no evidence for a waning of effectiveness after one year. Simultaneous modelling of invasive pneumococcal disease and epidemic strain meningococcal B suggests a degree of residual confounding that reduces the effectiveness estimate to 68%. There is evidence for some cross-protection of MeNZB against non-epidemic strains.The MeNZB vaccine was effective against the New Zealand epidemic strain of meningococcal B disease. Between July 2004 and December 2008 an estimated 210 epidemic strain cases (95% CI 100-380), six deaths and 15-30 cases of severe sequelae were avoided in New Zealand due to the introduction of the MeNZB vaccine.     

A+C群脑膜炎球菌多糖疫苗安全性和免疫原性的研究

目的 以分组对照法观察A＋C群脑膜炎球菌多糖疫苗对6～24月龄幼儿和5～13岁儿童接种后的安全性和免疫原性。方法 观察组共428名儿童,分为2个年龄段接种A＋C群脑膜炎球菌多糖疫苗,接种剂量为每人100μg;阳性对照组103人接种A群脑膜炎球菌多糖疫苗,接种剂量为每人50μg;阴性对照组94人接种伤寒Vi多糖疫苗,接种剂最为每人30μg;各组于接种后6、24、48和72 h测量体温并观察全身和局部反应,并于免疫前、后1个月分别收集血清标本,观察组2个年龄段儿童各不少于50名于免疫后6个月和1年再次收集血清标本,免疫前后收集到的血清采用体外杀菌力试验方法进行杀菌抗体水平的测定。结果 疫苗接种后人体反应轻微,428名儿童仅有3名（0．7%）出现中、强发热反应,有4名（0．9%）出现局部红晕,48h后反应全部消失。5～13岁儿童组免疫后1个月抗A和C群脑膜炎球菌杀菌抗体4倍增长率分别为96．59%和92．15%,免后1年的4倍增长率仍保持在90．91%和90．08%。结论A＋C群脑膜炎球菌多糖疫苗接种后具有较好的安全性和免疫原性。     

Immunogenicity and safety of the quadrivalent meningococcal vaccine MenACWY-TT co-administered with a combined diphtheria-tetanus-acellular pertussis vaccine versus their separate administration in adolescents and young adults: A phase III,randomized study

BackgroundThis study evaluated the immunogenicity and safety of quadrivalent meningococcal conjugate vaccine using tetanus (T) toxoid as carrier protein (MenACWY-TT) co-administered with combined diphtheria-tetanus-acellular pertussis vaccine (Tdap) versus their separate administration in adolescents and young adults.MethodsIn this phase III, randomized, partially-blind study (NCT01767376), healthy 11–25-year-olds (N = 660) were randomized (1:1:1) to receive MenACWY-TT and Tdap at Month 0 (Co-ad group), MenACWY-TT at Month 0 and Tdap at Month 1 (ACWY_Tdap group) or Tdap at Month 0 and MenACWY-TT at Month 1 (Tdap_ACWY group). Immune responses to MenACWY-TT were measured by serum bactericidal assay using rabbit complement (rSBA). Anti-diphtheria (D), anti-tetanus (T), anti-pertussis toxin (PT), anti-filamentous hemagglutinin (FHA) and anti-pertactin (PRN) antibody concentrations were assessed using enzyme-linked immunosorbent assays. Non-inferiority of immunogenicity was assessed using pre-defined clinical criteria. Safety was also evaluated.ResultsNon-inferiority of immunogenicity of MenACWY-TT and Tdap when co-administered versus their separate administration was demonstrated in terms of rSBA geometric mean titers (GMTs) for 4 meningococcal serogroups and of the percentage of participants with antibody concentrations >1 IU/ml for D and T. Among the pertussis antigens, non-inferiority criteria for geometric mean concentrations (GMCs) were reached for PT, but not met for FHA and PRN. Across all groups, ≥93.2% of participants had vaccine responses to each meningococcal serogroup, ≥99.1% were seroprotected against T and D, and ≥85.5% had booster responses to each pertussis antigen. Robust increases in antibody GMTs/GMCs were observed for all antigens between pre-and post-vaccination. Both vaccines had clinically acceptable safety profiles.ConclusionImmune responses to MenACWY-TT and to the T and D antigens from Tdap were not impacted by their co-administration. The lower antibody concentrations observed against the pertussis components may be of limited clinical relevance since robust anti-pertussis booster responses were observed. This study supports concurrent administration of the 2 vaccines in adolescents.     

A phase 2 open-label safety and immunogenicity study of a meningococcal B bivalent rLP2086 vaccine in healthy adults

Background

Neisseria meningitidis serogroup B (MnB) is a leading cause of bacterial meningitis and septicemia in adolescents and young adults. No currently licensed and available vaccine has been shown to provide broad protection against endemic MnB disease. A bivalent rLP2086 vaccine based on two factor H-binding proteins (fHBPs) has been developed to provide broad protection against MnB disease-causing strains.

Methods

This study assessed the safety and immunogenicity of the final formulation of a bivalent rLP2086 vaccine in 60 healthy adults (18–40 years of age) receiving 120 μg doses at 0, 1, and 6 months. Safety was assessed by collecting solicited reactogenicity data and participant-reporting of adverse events. Immunogenicity was evaluated by human serum bactericidal assay (hSBA) against 5 MnB strains expressing distinct fHBP variants and fHBP-specific immunoglobulin G titre.

Results

After each immunisation, local reactions such as pain at the injection site and erythema were generally mild or moderate. The most common vaccine-related adverse event was upper respiratory tract infection, which was reported by two participants. Seroprotection (hSBA titres ≥ 1:4) was achieved in 94.3% of participants against a MnB strain expressing the vaccine-homologous fHBP variant A05 and 70.0%–94.7% against MnB strains expressing the heterologous fHBP variants B02, A22, B44, and B24. Seroconversion rates (≥4-fold rise in hSBA titres) ranged from 70.0% to 94.7% across the five MnB test strains following the 3-dose vaccination regimen. Immunogenicity responses tended to increase upon subsequent vaccine doses.

Conclusions

Bivalent rLP2086 is a promising vaccine candidate for broad protection against MnB disease-causing strains.     

From secondary prevention to primary prevention: a unique strategy that gives hope to a country ravaged by meningococcal disease

New Zealand has been affected by an epidemic of group B meningococcal disease dominated by a strain defined as, B:4:P1.7b,4. Over 5550 cases and 222 deaths have been reported since 1991 in a population of 4 million people.Meningococcal disease cases notified on EpiServ database operated by Institute of Environmental Science and Research Limited through to 30 September 2004. Through the collaborative efforts of a government agency, vaccine company, university and laboratory institute, clinical trials of the Chiron produced outer membrane vesicle (OMV) strain-specific MeNZB vaccine were run in rapid succession. The delivery of MeNZB will be New Zealand's largest immunisation programme with three doses given at 6-week intervals to over 1 million people aged 6 weeks-19 year olds inclusive. Planning, co-ordinating and delivering the immunisation programme is a challenging project for the New Zealand Health Sector.     

Safety and immunogenicity of a Proteosome -trivalent inactivated influenza vaccine, given nasally to healthy adults

We studied the safety and immunogenicity of a nasally administered vaccine comprising three monovalent inactivated influenza antigens (A/New Caledonia/20/99 (H1N1), A/Panama/2007/99 (H3N2), and B/Guangdong/120/2000) non-covalently associated with outer membrane proteins of Neisseria meningitidis (Proteosome) in normal, healthy adults. In a randomized, double-blind trial participants (n = 78) were allocated to placebo or a single nasal dose of vaccine containing 15, 30, or 45 microg of each of the three HA antigens, or two nasal doses containing 30 microg of each HA, separated by 2 weeks. The vaccine was generally well tolerated in all doses tested, and in a one or two-dose schedule. A shallow vaccine reactogenicity dose-response was seen. The most common local reaction was nasal congestion, which occurred in up to 48.3% of vaccine recipients in days 0-6 after vaccine but was mild and self-limiting; this reaction was not significantly more common among active vaccine recipients than placebo recipients. Mild to moderate headache was the most commonly reported systemic reactogenicity complaint in all treatment groups, and was the only solicited complaint to increase significantly in frequency after a second active dose. No severe systemic reactions occurred. A positive and statistically significant antibody response was observed, in serum and in nasal secretions, to increasing dose for all three antigens. Serum HAI titre responses and nasal secretory IgA immune responses were elicited against all three antigens. Further testing of this nasal influenza vaccine is warranted to determine its safety and immunogenicity in these populations and its efficacy in the prevention of clinical illness.     

An evaluation of the immunogenicity and safety of a new trivalent meningococcal polysaccharide vaccine

The immunogenicity and safety of a meningococcal trivalent A/C/W135 polysaccharide vaccine was compared with that of a tetravalent A/C/Y/W135 polysaccharide vaccine in a randomised, double blind trial. The study included 360 adults, who received either a trivalent or tetravalent polysaccharide meningococcal vaccine. Antibody responses were determined by serum bactericidal antibody (rSBA) assays prior to vaccination and on day 28 and month 11 after vaccination. The percentage of participants in the trivalent vaccine group who had rSBA titres >or=8 on day 28 post-vaccination against serogroups A, C and W135 meningococci were 99, 98 and 91%, respectively. The corresponding figures in the tetravalent vaccine group were 99, 99 and 90%. The percentage of participants with various cut off levels of rSBA against serogroups A, W135 and C meningococci on day 28 and 11-month post-vaccination and the incidence of adverse events did not differ significantly between the two groups.     

Immunogenicity and safety of a hexavalent meningococcal outer-membrane-vesicle vaccine in children of 2-3 and 7-8 years of age

To study the reactogenicity and immunogenicity of a hexavalent meningococcal outer-membrane-vesicle vaccine (OMV), two different dosages of this vaccine (7.5 and 15 microg of individual PorA proteins) consisting of vesicles expressing class 1 outer-membrane proteins (OMPs) of subtypes P1.7,16; P1.5,2; P1.19,15 and P1.5(c), 10; P1.12,13; P1.7(h),4 were administered to a group of 7-8 year (n=165) and a group of 2-3 year old children (n=172). Control groups of children with similar ages were vaccinated against hepatitis B. All participants received three injections. Pre- and postimmunisation sera were tested for bactericidal antibodies against six isogenic meningococcal vaccine strains expressing different PorA proteins. Antibody titres against OMP of the two different vesicles (PL16215 and PL10124) were measured by ELISA. The meningococcal hexavalent OMV vaccine was well tolerated. No statistically significant differences were seen between the high and low dose of hexavalent meningococcal OMV vaccine. The percentage of children showing a fourfold increase of bactericidal antibody titres against the specific serosubtype varied in toddlers from 28 to 98% and in older children from 16 to 100%. Both ELISA antibody titres and bactericidal activity showed the highest level in the youngest age-group.     

Immunogenicity,reactogenicity, and safety of inactivated quadrivalent influenza vaccine candidate versus inactivated trivalent influenza vaccine in healthy adults aged ≥18 years: A phase III,randomized trial

Background

Two influenza B lineages have been co-circulating since the 1980s, and because inactivated trivalent influenza vaccine (TIV) contains only one B strain, it provides little/no protection against the alternate B-lineage. We assessed a candidate inactivated quadrivalent influenza vaccine (QIV) containing both B lineages versus TIV in healthy adults.

Methods

Subjects received one dose of QIV (lot 1, 2, or 3) or one of two TIVs (B strain from Victoria or Yamagata lineage); randomization was 2:2:2:1:1. Hemagglutination-inhibition assays were performed 21-days post-vaccination; superiority of QIV versus TIV for the alternate B-lineage was demonstrated if the 95% confidence interval (CI) lower limit for the GMT ratio was ≥1.5, and non-inferiority against the shared strains was demonstrated if the 95% CI upper limit for the GMT ratio was ≤1.5. Reactogenicity and safety were assessed during the post-vaccination period. NCT01196975.

Results

Immunogenicity of QIV lots was consistent, QIV was superior to TIV for the alternate B-lineage strain, and QIV was non-inferior versus TIVs for shared strains (A/H1N1, A/H3N2, B-strain). Reactogenicity and safety profile of the QIV was consistent with seasonal influenza vaccines.

Conclusion

QIV provided superior immunogenicity for the added B strain without affecting the antibody response to the TIV strains, and without compromising safety.     

Active-controlled phase III study of an egg-cultivated quadrivalent inactivated split-virion influenza vaccine (GC3110A) in healthy Korean children aged 6–35 months

The inactivated trivalent influenza vaccine (TIV) offers limited protection when two influenza B lineages co-circulate or when there is a vaccine mismatch (i.e., discordance in the predominant circulating B strain and WHO-recommended B strain). Inactivated quadrivalent influenza vaccine (QIV) may reduce the burden of influenza. Here, we report the results of a phase 3 clinical trial that evaluated the immunogenicity and safety of a novel QIV, GC3110A, in Korean children aged 6–35 months, which has been approved and is currently in use in Korea. The study involved two parts. In Part 1, the safety of GC3110A was evaluated in 10 subjects. After none of the subjects reported grade 3 adverse events (AEs), we proceeded to Part 2. Part 2 was a randomized, double-blind, multicenter phase 3 trial wherein we compared the immunogenicity and safety of GC3110A with those of a licensed control TIV. Immunogenicity was evaluated by measuring hemagglutination inhibition titers. The 200 participants enrolled in Part 2 were randomized in a 4:1 ratio to receive GC3110A or control TIV. The study vaccine group met both primary (i.e., the lower limit of 95% confidence interval [CI] of the seroconversion rate exceeds 40% for four strains) and secondary (i.e., the lower limit of 95% CI of the seroprotection rate exceeds 70% for four strains) immunogenicity endpoints. There was no significant between-group difference in the seroconversion rate, seroprotection rate, and geometric mean titer for the shared strains. However, the study vaccine group demonstrated significantly higher immunity for the additional strain B/Yamagata. In the safety analysis, there was no significant between-group difference in the proportion of participants with solicited local AEs, solicited systemic AEs, and unsolicited AEs. In conclusion, the results indicate that GC3110A has comparable immunogenicity and safety to those of TIV.Clinical Trial Registry Number: NCT03285997.     

Antibody responses to meningococcal (groups A, C, Y and W135) polysaccharide diphtheria toxoid conjugate vaccine in children who previously received meningococcal C conjugate vaccine

A randomised, modified, double-blind trial was conducted in children 2 to < 5 years of age to evaluate immunogenicity and reactogenicity of a meningococcal (serogroups A, C, Y, W135) diphtheria toxoid conjugate vaccine (MCV-4) in healthy children previously vaccinated with a monovalent meningococcal C conjugate vaccine. Participants received one dose of either MCV-4 or Haemophilus influenzae type b vaccine (Hib vaccine, control group). Serum bactericidal antibodies (SBA) were determined in sera obtained before and approximately 28 days following vaccination. MCV-4 was highly immunogenic for serogroups A, C, Y and W135, the response to serogroup C being consistent with a booster response in participants primed with monovalent C conjugate vaccine. No major between-group differences in solicited local and systemic reactions or adverse events (AEs).     

A randomised, double-blind, controlled trial of the immunogenicity and tolerability of a meningococcal group C conjugate vaccine in young British infants

A double-blind, randomised, controlled trial was conducted in 248 British infants to assess the immunogenicity and tolerability of three doses of a meningococcal group C/CRM (197) conjugate vaccine (Lederle Laboratories, USA) given at 2, 3 and 4 months. Control children received three doses of Hepatitis B vaccine (Engerix B(R); SmithKline Beecham). At 5 months of age, 100% of children receiving the conjugate vaccine had specific immunoglobulin G concentrations >2.0 microg/ml (n=116) compared with only 4% of control children (n=121). Those receiving the conjugate also had 2.5- and 1.6-fold higher geometric mean concentrations of PRP and diphtheria antibodies, respectively. The vaccine was well tolerated.     

甲肝灭活疫苗(Vero细胞)在2岁以上中国健康人群的免疫原性和安全性研究

目的比较甲型肝炎(甲肝)灭活疫苗(Vero细胞)与甲肝灭活疫苗(二倍体细胞)在2岁以上健康人群中的免疫原性和安全性。方法采用随机、盲法、对照的设计,选择2 100名2岁以上甲肝易感者,分为A、B两组,按照0、6月免疫程序,接种甲肝灭活疫苗(Vero细胞)或甲肝灭活疫苗(二倍体细胞)并观察安全性;所有受试者于免前、全程免后1个月采血(前600名还需采集首剂免疫后1个月血样),采用间接酶联免疫吸附试验方法(ELISA)检测抗甲肝病毒抗体(抗-HAV),评价免疫效果。结果 1剂后A组抗-HAV阳转率为96.05%(成人)和92.78%(儿童),B组为94.92%(成人)和96.61%(儿童);2剂后A组为99.61%(成人)和99.53%(儿童),B组为99.41%(成人)和100.00%(儿童)。两组间抗-HAV阳转率均无统计学差异。安全性方面,A组不良反应率为32.41%(成人)和53.61%(儿童),B组为35.56%(成人)和53.33%(儿童),1级反应为主,组间无统计学差异。结论甲肝灭活疫苗(Vero细胞)对2岁以上的人群免疫原性和安全性良好。     

人用狂犬病无佐剂纯化疫苗的安全性与免疫原性的初步观察

目的评价国产人用狂犬病无佐剂纯化疫苗(Vero细胞微载体)的安全性和免疫原性。方法对502人(A组)接种人用狂犬病无佐剂纯化疫苗(Vero细胞微载体)另100人(B组)作为对照接种巴斯德公司生产的狂犬病纯化疫苗。采用0、3、7、14和28天程序,观察每针次接种后72小时内局部和全身反应及14天、45天的免疫应答水平。结果所有接种对象均未出现严重局部和全身副反应。首剂免疫14天,A、B组抗体阳性率均达到100%,几何平均滴度为5.2IU/ml和5.6IU/ml。第45天,A组抗体几何平均滴度上升至9.5IU/mll,与B组相似(9.8IU/ml)。结论人用狂犬病无佐剂纯化疫苗(Vero细胞微载体)具有良好安全性和免疫原性。     

Seasonal influenza vaccine delivered by intradermal microinjection: A randomised controlled safety and immunogenicity trial in adults

Influenza vaccines remain largely underused. A promising alternative to current intramuscular vaccines is a trivalent inactivated influenza vaccine (TIV) delivered using a microinjection system to offer a less invasive and possibly more acceptable vaccination. A phase II, multicentre, randomised open-label study in 978 healthy adults (18-57 years) evaluated the immunogenicity and safety of intradermal TIV. Subjects received a 0.1 ml injection of intradermal TIV, containing 9 microg of haemagglutinin (HA) per strain (n = 588) or a conventional 0.5 ml intramuscular vaccine (15 microg of HA/strain; n = 390). Intradermal TIV induced non-inferior humoral immune responses against all three strains and superior responses against both A strains (H1N1, H3N2) compared with the control. Both vaccines were well tolerated.