Immunogenicity of the UK group B meningococcal vaccine (4CMenB) schedule against groups B and C meningococcal strains (Sched3): outcomes of a multicentre, open-label, randomised controlled trial.

Background: The use of the multicomponent meningococcal vaccine 4CMenB in the UK schedule at 2, 4, and 12 months of age has been shown to be 59·1% effective at preventing invasive group B meningococcal disease. Here, we report the first data on the immunogenicity of this reduced-dose schedule to help to interpret this effectiveness estimate.

Methods: In this multicentre, parallel-group, open-label, randomised clinical trial, infants aged up to 13 weeks due to receive their primary immunisations were recruited via child health database mailouts in Oxfordshire and via general practice surgeries in Gloucestershire and Hertfordshire.

Immunogenicity and safety of a quadrivalent meningococcal tetanus toxoid-conjugate vaccine (MenACYW-TT) in healthy toddlers: a Phase II randomized study.

can lead to invasive meningococcal disease to which young children are particularly vulnerable. We assessed the immunogenicity and safety of Sanofi Pasteur's investigational quadrivalent (serogroups A, C, Y, and W) meningococcal tetanus-toxoid conjugate vaccine, MenACYW-TT, as a single dose, in healthy meningococcal vaccine-naïve toddlers versus a licensed conjugate vaccine MCV4-TT (NCT03205358). In this Phase II study conducted in Finland, 188 toddlers aged 12-24 months were randomized 1:1 to MenACYW-TT or MCV4-TT.

Kinetics of maternally-derived serogroup A, C, Y and W-specific meningococcal immunoglobulin G in Malian women and infants.

A prospective, randomised, controlled observer-blind trial measuring the efficacy and immunogenicity of trivalent influenza vaccine (TIV) and the immunogenicity of quadrivalent meningococcal conjugate vaccine (MCV) in pregnant women and their infants up to 6 months of age was conducted in Mali. Here we reported the immunogenicity of MCV, which was used as a comparator vaccine to TIV, in this population. Third-trimester pregnant Malian women were randomized to receive TIV or MCV.

Serogroup C disease epidemiology, seroprevalence, vaccine effectiveness and waning immunity, England, 1998/99 to 2015/16.

BackgroundIn 1999, the United Kingdom (UK) was the first country to introduce meningococcal group C (MenC) conjugate vaccination. This vaccination programme has evolved with further understanding, new vaccines and changing disease epidemiology.AimTo characterise MenC disease and population protection against MenC disease in England.

Antibody Persistence at the Population Level 5 Years After Mass Vaccination With Meningococcal Serogroup A Conjugate Vaccine (PsA-TT) in Burkina Faso: Need for a Booster Campaign?

Background: In Burkina Faso, serogroup A meningococcal (NmA) conjugate vaccine (PsA-TT, MenAfriVac) was introduced through a mass campaign in children and adults in December 2010. Similar to a serological survey in 2011, we followed population-level antibody persistence for 5 years after the campaign and estimated time of return to previously-published pre-vaccination levels.

Methods: We conducted 2 cross-sectional surveys in 2013 and early 2016, including representative samples (N = 600) of the general population of Bobo-Dioulasso, Burkina Faso.

Safety and immunogenicity of a pentavalent meningococcal conjugate vaccine containing serogroups A, C, Y, W, and X in healthy adults: a phase 1, single-centre, double-blind, randomised, controlled study.

Background: Invasive meningococcal disease is an important public health problem, especially in sub-Saharan Africa. After introduction of MenAfriVac in 2010, Neisseria meningitidis serogroup A disease has been almost eliminated from the region. However, serogroups C, W, Y, and X continue to cause disease outbreaks.

Effect of Tdap upon antibody response to meningococcal polysaccharide when administered before, with or after the quadrivalent meningococcal TT-conjugate vaccine (coadministered with the 13-valent pneumococcal CRM197-conjugate vaccine) in adult Hajj pilgrims: A randomised controlled trial.

Hajj pilgrims are susceptible to several serious infections and are required to receive multiple vaccinations. Polysaccharide-protein conjugate vaccines contain carrier proteins such as tetanus toxoid (TT), diphtheria toxoid or a mutant of diphtheria toxoid (CRM197). These carrier proteins may interact with other conjugate or combination vaccines containing tetanus or diphtheria on concurrent or sequential administration.

Natural immunity against capsular group X N. meningitidis following an outbreak in Togo, 2007.

Background: Capsular group X N. meningitidis (MenX) has emerged as a cause of localized disease outbreaks in sub-Saharan Africa, but the human immune response following exposure to MenX antigens is poorly described. We therefore assessed the natural immunity against MenX in individuals who were living in an area affected by a MenX outbreak during 2007 in Togo, West Africa.

Investigation of correlates of protection against pharyngeal carriage of Neisseria meningitidis genogroups W and Y in the African meningitis belt.

Background: Serum bactericidal antibody titres that correlate with protection against invasive meningococcal disease have been characterised. However, titres that are associated with protection against acquisition of pharyngeal carriage of Neisseria meningitidis are not known.

Methods: Sera were obtained from the members of a household in seven countries of the African meningitis belt in which a pharyngeal carrier of N.

Antibody persistence after serogroup C meningococcal conjugate vaccine in children with sickle cell disease.

Background: A decline of protective antibody titers after MCC vaccine has been demonstrated in healthy children, this may be an issue of concern for risk groups. The aim of this study was to evaluate the persistence of bactericidal antibodies after MCC vaccine in sickle cell disease (SCD) patients. The type of vaccine used and booster response were also analyzed.

Correction: A Seroepidemiological Study of Serogroup A Meningococcal Infection in the African Meningitis Belt.

[This corrects the article DOI: 10.1371/journal.pone.

Children with Haemophilus influenzae type b (Hib) vaccine failure have long-term bactericidal antibodies against virulent Hib strains with multiple capsular loci.

Children who develop invasive Haemophilus influenzae serotype b (Hib) disease after immunisation with a highly-effective conjugate vaccine are more likely to have been infected with Hib strains possessing multiple copies of the capsulation locus. Using a recently-validated serum bactericidal antibody (SBA) assay, we tested convalescent sera from 127 Hib vaccine failure cases against clinical Hib strains expressing 1-5 copies of the capsulation locus. SBA titres correlated weakly with anti-capsular IgG antibody concentrations and there was no association between SBA geometric mean titres and number of capsulation locus copies.

What Would be the Best Schedule for Prevention of Meningococcal Disease in All Ages? The UK Experience.

Meningococcal disease is a major global public health problem, and vaccination is the optimal means of prevention. Meningococcal vaccination programmes have significantly evolved, for example, in the UK, since their introduction in 1999. The UK, the first country to introduce meningococcal serogroup C conjugate (MCC) vaccination, commenced this in 1999 with a primary infant series at 2, 3 and 4 months of age, together with a catch-up campaign of a single dose for children aged 1-18 years.

A Seroepidemiological Study of Serogroup A Meningococcal Infection in the African Meningitis Belt.

The pattern of epidemic meningococcal disease in the African meningitis belt may be influenced by the background level of population immunity but this has been measured infrequently. A standardised enzyme-linked immunosorbent assay (ELISA) for measuring meningococcal serogroup A IgG antibodies was established at five centres within the meningitis belt. Antibody concentrations were then measured in 3930 individuals stratified by age and residence from six countries.

Interactions of conjugate vaccines and co-administered vaccines.

Conjugate vaccines play an important role in the prevention of infectious diseases such as those caused by the bacteria Haemophilus influenzae (Hi) type b (Hib), Neisseria meningitidis, and Streptococcus pneumoniae. Vaccines developed against these 3 pathogens utilize 3 main carrier proteins, non-toxic mutant of diphtheria toxin (CRM197), diphtheria toxoid (DT) and tetanus toxoid (TT). Current pediatric immunisation schedules include the administration of several vaccines simultaneously, therefore increasing the potential for immune interference (both positively and negatively) to the antigens administered.

Neisseria meningitidis Group A IgG1 and IgG2 Subclass Immune Response in African Children Aged 12-23 Months Following Meningococcal Vaccination.

Background: A group A meningococcal conjugate vaccine, PsA-TT, was licensed in 2010 and was previously studied in a phase 2 clinical trial to evaluate its safety and immunogenicity in African children 12-23 months of age.

Methods: Subjects received either PsA-TT; meningococcal group A, C, W, Y polysaccharide vaccine (PsACWY); or Haemophilus influenzae type b conjugate vaccine (Hib-TT). Forty weeks following primary vaccination, the 3 groups were further randomized to receive either PsA-TT, one-fifth dose of PsACWY, or Hib-TT.

Human Complement Bactericidal Responses to a Group A Meningococcal Conjugate Vaccine in Africans and Comparison to Responses Measured by 2 Other Group A Immunoassays.

Background: PsA-TT (MenAfriVac) is a conjugated polysaccharide vaccine developed to eliminate group A meningococcal disease in Africa. Vaccination of African study participants with 1 dose of PsA-TT led to the production of anti-A polysaccharide antibodies and increased serum bactericidal activity measured using rabbit complement (rSBA). Bactericidal responses measured with human complement (hSBA) are presented here.

Population-Level Persistence of Immunity 2 Years After the PsA-TT Mass-Vaccination Campaign in Mali.

Background: In 2010, Africa's first preventive meningococcal mass vaccination campaign was launched using a newly developed Neisseria meningitidis group A (NmA) polysaccharide-tetanus toxoid conjugate vaccine, PsA-TT (MenAfriVac), designed specifically for the meningitis belt. Given PsA-TT's recent introduction, the duration of protection against meningococcal group A is unknown.

Methods: We conducted a household-based, age-stratified seroprevalence survey in Bamako, Mali, in 2012, 2 years after the vaccination campaign targeted all 1- to 29-year-olds.

Meningococcal Seroepidemiology 1 Year After the PsA-TT Mass Immunization Campaign in Burkina Faso.

Background: A group A meningococcal (MenA) conjugate vaccine, PsA-TT (MenAfriVac), was introduced in Burkina Faso via mass campaigns between September and December 2010, targeting the 1- to 29-year-old population. This study describes specific antibody titers in the general population 11 months later and compares them to preintroduction data obtained during 2008 using the same protocol.

Methods: During October-November 2011, we recruited a representative sample of the population of urban Bobo-Dioulasso aged 6 months to 29 years, who underwent standardized interviews and blood draws.

Antibody Persistence at 1 and 4 Years Following a Single Dose of MenAfriVac or Quadrivalent Polysaccharide Vaccine in Healthy Subjects Aged 2-29 Years.

Background: Mass vaccination campaigns of the population aged 1-29 years with 1 dose of group A meningococcal (MenA) conjugate vaccine (PsA-TT, MenAfriVac) in African meningitis belt countries has resulted in the near-disappearance of MenA. The vaccine was tested in clinical trials in Africa and in India and found to be safe and highly immunogenic compared with the group A component of the licensed quadrivalent polysaccharide vaccine (PsACWY). Antibody persistence in Africa and in India was investigated.

Antibody Persistence 1-5 Years Following Vaccination With MenAfriVac in African Children Vaccinated at 12-23 Months of Age.

Background: Following mass vaccination campaigns in the African meningitis belt with group A meningococcal conjugate vaccine, MenAfriVac (PsA-TT), disease due to group A meningococci has nearly disappeared. Antibody persistence in healthy African toddlers was investigated.

Methods: African children vaccinated at 12-23 months of age with PsA-TT were followed for evaluation of antibody persistence up to 5 years after primary vaccination.

Antibody responses after primary immunization in infants born to women receiving a pertussis-containing vaccine during pregnancy: single arm observational study with a historical comparator.

Introduction: In England, antenatal pertussis immunization using a tetanus/low-dose diphtheria/5-component acellular-pertussis/inactivated-polio (TdaP5/IPV) vaccine was introduced in October 2012. We assessed infant responses to antigens in the maternal vaccine and to those conjugated to tetanus (TT) or the diphtheria toxin variant, CRM.

Methods: Infants of 141 TdaP5/IPV-vaccinated mothers in Southern England immunized with DTaP5/IPV/Haemophilus influenzae b (Hib-TT) vaccine at 2-3-4 months, 13-valent pneumococcal vaccine (PCV13, CRM-conjugated) at 2-4 months and 1 or 2 meningococcal C vaccine (MCC-CRM- or MCC-TT) doses at 3-4 months had blood samples taken at 2 and/or 5 months of age.

Randomized Trial to Compare the Immunogenicity and Safety of a CRM or TT Conjugated Quadrivalent Meningococcal Vaccine in Teenagers who Received a CRM or TT Conjugated Serogroup C Vaccine at Preschool Age.

Background: Protection after meningococcal C (MenC) conjugate (MCC) vaccination in early childhood is short-lived. Boosting with a quadrivalent vaccine in teenage years, a high-risk period for MenC disease, should protect against additional serogroups but might compromise MenC response. The carrier protein in the primary MCC vaccine determines the response to MCC booster in toddlers, but the relationship between primary vaccine and booster given later is unclear.

Safety and immunogenicity of a four-component meningococcal group B vaccine (4CMenB) and a quadrivalent meningococcal group ACWY conjugate vaccine administered concomitantly in healthy laboratory workers.

Safety precautions for laboratory staff working with meningococci should primarily rely on laboratory procedures preventing exposure to aerosols containing viable meningococci. Despite this, vaccination is a key component of protection in the occupational setting. In the UK in 2009, there were no licensed vaccines for meningococcal capsular group B or conjugate vaccines for capsular groups A, C, W and Y.