Quadrivalent Meningococcal Vaccine Research Articles

Immunogenicity and safety of a new meningococcal A conjugate vaccine in Indian children aged 2–10 years: A Phase II/III double-blind randomized controlled trial

This study compares the immunogenicity and safety of a single dose of a new meningococcal A conjugate vaccine (PsA-TT, MenAfriVac™, Serum Institute of India Ltd., Pune) against the meningococcal group A component of a licensed quadrivalent meningococcal polysaccharide vaccine (PsACWY, Mencevax ACWY®, GSK, Belgium) 28 days after vaccination in Indian children. This double-blind, randomized, controlled study included 340 Indian children aged 2–10 years enrolled from August to October 2007; 169 children received a dose of PsA-TT while 171 children received a dose of PsACWY. Intention-to-treat analysis showed that 95.2% of children in PsA-TT group had a ≥4-fold response in serum bactericidal titers (rSBA) 28 days post vaccination as compared to 78.2% in the PsACWY group. A significantly higher rSBA GMT (11,209, 95%CI 9708–12,942) was noted in the PsA-TT group when compared to PsACWY group (2838, 95%CI 2368–3401). Almost all children in both vaccine groups had a ≥4-fold response in group A-specific IgG concentration but the IgG GMC was significantly greater in the PsA-TT group (89.1μg/ml, 95%CI 75.5–105.0) when compared to the PsACWY group (15.3μg/ml, 95%CI 12.3–19.2). Local and systemic reactions during the 4 days after immunization were similar for both vaccine groups except for tenderness (30.2% in PsA-TT group vs 12.3% in PsACWY group). None of the adverse events or serious adverse events was related to the study vaccines. We conclude that MenAfriVac™ is well tolerated and significantly more immunogenic when compared to a licensed polysaccharide vaccine, in 2-to-10-year-old Indian children.

Immunogenicity and Safety of a Meningococcal Quadrivalent Conjugate Vaccine in Saudi Arabian Adolescents Previously Vaccinated with One Dose of Bivalent and Quadrivalent Meningococcal Polysaccharide Vaccines: a Phase III, Controlled, Randomized, and Modified Blind-Observer Study

Reduced immune responses to repeated polysaccharide vaccination have been previously reported, but there are limited immunogenicity data on the use of meningococcal polysaccharide vaccine (PSV) followed by meningococcal conjugate vaccine. Saudi Arabian adolescents (aged 16 to 19 years) who had previously been vaccinated with ≥1 dose of bivalent meningococcal polysaccharide vaccine and 1 dose of quadrivalent meningococcal polysaccharide (MPSV4) were enrolled in a controlled, randomized, and modified observer-blind study (collectively termed the PSV-exposed group). The PSV-exposed group was randomized to receive either quadrivalent meningococcal conjugate vaccine (MCV4) (n = 145 PSV-exposed/MCV4 group) or MPSV4 (n = 142 PSV-exposed/MPSV4 group), and a PSV-naïve group received MCV4 (n = 163). Serum samples collected prevaccination and 28 days postvaccination were measured by baby rabbit serum bactericidal antibody (rSBA) assay, and vaccine tolerability and safety were also evaluated. For each serogroup, the postvaccination geometric mean titers (GMTs) were significantly higher in the PSV-naïve group than in either group comprised of the PSV-exposed participants. The postvaccination serogroup C rSBA GMT was significantly higher in the PSV-MCV4 group than in the PSV-MPSV4 group after adjusting for prevaccination GMTs. Although not statistically significant, similar differences were observed for serogroups A, Y, and W-135. No worrisome safety signals were detected. This study demonstrated MCV4 to be safe and immunogenic in those who had previously received polysaccharide vaccination, and it suggests that conjugate vaccine can partially compensate for the hyporesponsiveness seen with repeated doses of polysaccharide vaccine.

MenACWY-TT vaccine for active immunization against invasive meningococcal disease

Meningococcal disease remains a significant global cause of morbidity and mortality despite the availability of polysaccharide and conjugate vaccines. The implementation of monovalent meningococcal serogroup C vaccine in developed countries has significantly decreased the incidence of meningococcal disease, while the recent introduction of monovalent serogroup A conjugate vaccine in the African meningitis belt aims to reduce the incidence of high endemic disease in this area. Three quadrivalent meningococcal vaccines have already been licensed; a polysaccharide (MenACWY-PS) and two conjugated (MenACWY-DT and MenACWY-CRM) vaccines. An investigational MenACWY-TT vaccine is described in this article. Clinical trials in infants older than 9 months of age, toddlers, children, adolescents and adults have indicated that this vaccine is well tolerated and immunogenic. The inclusion of a spacer molecule coupled with the polysaccharide (for serogroups A and C) and tetanus toxoid as the carrier protein aims to elicit robust immune responses. The tolerability of this vaccine is comparable to that of polysaccharide quadrivalent vaccines and monovalent meningococcal serogroup C vaccines. More importantly, the immunogenicity, antibody persistence and induction of immune memory aim to provide protection to a wide range of susceptible subjects.

Meningococcal vaccine development – from glycoconjugates against MenACWY to proteins against MenB – potential for broad protection against meningococcal disease

Novartis Vaccines has a long-standing research and development interest in the prevention of invasive meningococcal disease. From the initial licensure of the monovalent meningococcal C glycoconjugate vaccine, Menjugate®, in response to the emergence of a virulent serogroup C ST-11 strain in the United Kingdom to the more recent development and licensure of a quadrivalent meningococcal ACWY glycoconjugate vaccine, Menveo®, Novartis has a continuing commitment to the development of more effective tools for the control of meningococcal disease. Menveo is now licensed for use in adolescents and adults in over 50 countries and results from phase III studies have shown the vaccine to be well-tolerated and highly immunogenic in infants with vaccination beginning from 2 months of age. The ‘holy grail’ of meningococcal disease control is a broadly protective vaccine against serogroup B (MenB), preferably a vaccine that protects all age groups including infants. As the serogroup B capsule is poorly immunogenic, efforts over the past 40 years have focused on identifying conserved proteins expressed on the bacterial surface that elicit bactericidal antibodies. Novartis has approached this problem utilizing genomic tools to identify proteins meeting these criteria in a process now known as ‘reverse vaccinology’[1]. This process has resulted in a novel multicomponent MenB vaccine (4CMenB) that consists of four major immunogenic components (three subcapsular MenB protein antigens plus outer membrane vesicles (OMVs) which themselves provide multiple subcapsular antigens, the immunodominant one being PorA). These all induce bactericidal antibodies against the antigens that are important in determining the survival, function, and virulence of the meningococci. Phase II studies of 4CMenB have been completed and have demonstrated that the vaccine is highly immunogenic against reference meningococcal strains selected to support licensure. Post-vaccination sera from clinical studies have also been tested against a diverse panel of serogroup B strains to support the development of the Meningococcal Antigen Typing System (MATS), a tool used to predict vaccine strain coverage [2] This overview is intended to give a broad summary of the key clinical data derived from the Menveo and 4CMenB clinical development programs.

Vaccination of travelers: how far have we come and where are we going?

Vaccine recommendations are a prominent part of health preparations before international travel. We review progress made in the past decade regarding vaccines used primarily by persons traveling from high-income countries to low- and middle-income countries. The combined hepatitis A–B vaccine, the recently licensed Vero cell-derived Japanese encephalitis vaccine and conjugated quadrivalent meningococcal vaccines are discussed. This article provides updates on yellow fever vaccine-associated visceral and neurologic adverse events, indications for influenza vaccine in travelers, the rapid immunization schedule for tick-borne encephalitis vaccine, schedules for postexposure rabies prophylaxis, and new insights about oral cholera vaccines following the outbreak in Haiti. The future should bring vaccines for serogroup B Neiserria meningitidis, dengue and malaria, as well as an inactivated yellow fever vaccine.

Meningococcal vaccines in Canada: An update

Meningococcal infection is serious, often resulting in fulminant sepsis or meningitis. There are two main types of meningococcal conjugate vaccine currently available in Canada: serotype C meningococcal conjugate, and quadrivalent conjugate for serotypes A, C, Y, and W-135. The immunological characteristics that inform ongoing immunization policies, as well as some of the limits of current knowledge, are presented. All Canadian children should receive a conjugate meningococcal C vaccine (MCV-C) at 12 months of age, and either a booster dose of MCV-C or of quadrivalent meningococcal vaccine (MCV-4) in adolescence. Children at high risk of invasive meningococcal disease should start MCV-C at two months of age, and be given MCV-4 at two years of age.

Early clinical experience with a candidate meningococcal B recombinant vaccine (rMenB) in healthy adults

Background: The development of a broadly protective vaccine against meningococcal serogroup B is a well-recognized public health need. Whole-genome sequencing was used to identify meningococcal surface proteins that are conserved across strains. These proteins were incorporated into two investigational vaccines.Methods: Three randomized studies were performed to evaluate a three-component recombinant meningococcal serogroup B vaccine (rMenB) and rMenB plus outer membrane vesicles from the Norwegian outbreak strain 44/76 (rMenB+OMVNW). Participants were randomized to receive 3 or 4 doses of rMenB or rMenB+OMVNW or control vaccines and provided sera for exploratory immunogenicity testing against a panel of meningococcal serogroup B strains. A booster dose was administered 12 months after the initial primary series in one of the studies. The control cohort received a licensed quadrivalent meningococcal polysaccharide vaccine against serogroups A, C, W-135 and Y as well as hepatitis B vaccine as safety comparators. Solicited reactions within 7 days of any vaccination and adverse events throughout the studies were recorded.Results: One hundred four participants enrolled into the clinical trials. Both rMenB and rMenB+OMVNW induced immune responses to multiple serogroup B strains in the majority of participants. Compared with rMenB, rMenB+OMVNW appeared somewhat more immunogenic and reactogenic; the study was not adequately powered for statistical assessment of these small differences. Both investigational vaccines were more reactogenic than the licensed vaccines. Few vaccinees discontinued any study due to reactogenicity to any study vaccine administered.Conclusion: Based on the immunogenicity and reactogenicity results in these participants, both rMenB and rMenB+OMVNW were promising candidates for further investigation.

Meningococcal Disease: Shifting Epidemiology and Genetic Mechanisms That May Contribute to Serogroup C Virulence

During the past decade, monovalent serogroup C and quadrivalent (serogroups A, C, W135, Y) meningococcal vaccination programs have been introduced in multiple industrialized countries. Many of these programs have been successful in reducing the burden of disease due to vaccine-preventable serogroups of Neisseria meningitidis in target age groups. As a result, disease burden in these countries has decreased and is primarily serogroup B, which is not vaccine preventable. Despite the success of these programs, meningococcal disease continues to occur and there is always concern that serogroup C organisms will adapt their virulence mechanisms to escape pressure from vaccination. This review highlights the current epidemiology of meningococcal disease in Europe and United States, as well as genetic mechanisms that may affect virulence of serogroup C strains and effectiveness of new vaccines.

Immunization 2011: Expanding Coverage, Enhancing Protection

Annually, the ACIP of the Centers for Disease Control and Prevention issues a revised Adult Immunization Schedule that is approved by the major specialty societies representing physicians who care ...

Memory B cell responses following immunisation with polysaccharide and conjugate quadrivalent meningococcal ACYW135 vaccines in healthy adult volunteers

Neisseria meningitidis is a leading cause of meningitis and septicaemia. The development of quadrivalent protein-polysaccharide conjugate vaccines against serogroups A, C, W135 & Y offers the possibility of broader protection against the organism across all age groups. We present results of a planned interim analysis of an ongoing open-label randomised clinical trial in healthy adult volunteers aged 18-70 comparing 2 doses of a conjugate quadrivalent ACWY vaccine one month apart (Group 1) with one dose of a polysaccharide quadrivalent ACWY vaccine (ACWYVax®) followed by one dose of a conjugate quadrivalent ACWY vaccine one month later (Group 2).

Novel Quadrivalent Meningococcal A, C, W-135 and Y Glycoconjugate Vaccine for the Broader Protection of Adolescents and Adults

Meningococcal meningitis and septicemia are a persistent public health concern owing to the associated mortality and devastating long-term sequelae. People of all ages may be affected, with the disease burden being higher in at-risk groups. Vaccination is the most rational approach to the prevention of invasive meningococcal disease. A novel quadrivalent meningococcal (Men) serogroup A, C, W-135 and Y polysaccharide-protein conjugate vaccine (MenACWY-CRM), has recently been licensed for use in individuals aged at least 11 years old in the USA, Canada and Europe. One dose of MenACWY-CRM is well tolerated, and induces robust immunity to all constituent vaccine serogroups in 11-65 year old individuals. MenACWY-CRM was found to be noninferior to the quadrivalent meningococcal ACWY-diphtheria toxoid glycoconjugate vaccine, which is also licensed in the USA and Canada. In Europe, MenACWY-CRM is the first quadrivalent meningococcal glycoconjugate vaccine available to provide broader protection against Neisseria meningitidis serogroups A, C, W-135 and Y.

Comparison of the safety and immunogenicity of an investigational and a licensed quadrivalent meningococcal conjugate vaccine in children 2–10 years of age

BackgroundRoutine administration of quadrivalent meningococcal conjugate vaccine to adolescents and certain high risk groups is recommended in the United States and Canada. We compared the immunogenicity and safety of an investigational quadrivalent meningococcal vaccine conjugated to CRM-197 (MenACWY-CRM) with a licensed quadrivalent vaccine conjugated to diphtheria toxoid (MCV4) in children aged 2–10 years. MethodsEligible 2–5-year-olds were randomized 1:2:2 to receive either 2 doses of MenACWY-CRM, or 1 dose of MenACWY-CRM or MCV4; 6–10-year-olds were randomized 1:1 to receive a single dose of MenACWY-CRM or MCV4. The primary immunogenicity assessment was seroresponse separately for the two age cohorts 28 days following a single dose of MenACWY-CRM or MCV4. Noninferiority and superiority criteria were predefined. Solicited injection-site and systemic reactions were collected for the 7 days postvaccination. ResultsA total of 2907 children were randomized to receive study vaccine. MenACWY-CRM met statistical superiority criteria vs. MCV4 for groups W and Y and was noninferior for group C in both age strata. For group A, noninferiority criteria were not met; the group A seroresponse rates for MenACWY-CRM and MCV4, respectively were 72% (95% confidence interval 68–75%) and 77% (73–80%) in 2–5-year-olds and 77% (73–80%) and 83% (79–86%) in 6–10-year-olds. When the two age strata were combined (2–10-year-old children), MenACWY-CRM was noninferior to MCV4 for all four groups, and statistically superior for groups C, W, and Y. Safety parameters were similar across age cohorts and vaccines groups. ConclusionsMenACWY-CRM and MCV4 were immunogenic and well tolerated in children aged 2–10 years. Seroresponse to MenACWY-CRM was statistically noninferior to MCV4 for all groups, and statistically superior for groups C, W, and Y. Trial registrationClinicaltrials.gov identifier: NCT00616421.

The Risk of Meningococcal Disease in Travelers and Current Recommendations for Prevention

With the economic recovery gaining momentum, travel experts predict that tourism in all regions will increase in 2010 by an estimated 3% to 4%. 1 This increase in travel is forecasted to exceed 5% in Africa, Asia, and the Middle East, where the risk of acquiring meningococcal disease or becoming a carrier is higher. 2 When evaluating the need for vaccination in travelers, particularly for those traveling to developing world countries, it is important to consider not only the incidence rate but also the impact of the respective infection (Figure 1). 3 As an example, meningococcal disease is rarely reported in travelers, but the impact of this infection can be as devastating for travelers as for any other individual. With its rapid clinical course and narrow window for diagnosis, the potential for negative outcomes from meningococcal disease may be increased particularly in travelers to remote locations where access to adequate health care facilities and antibiotics is limited. There is an additional public health concern with meningococcal infection, as travelers who are carriers may spread the infection in the society back home. Figure 1 Impact and incidence of vaccine‐preventable diseases in travelers to developing countries. 3 PPD = purified protein derivative, a tuberculin test. Outbreaks of meningococcal disease frequently occurred among Hajj pilgrims, their contacts, and thereafter even in persons without known contacts prior to 2002, when authorities of the Kingdom of Saudi Arabia issued a quadrivalent meningococcal vaccination requirement to obtain a Hajj visa. 4,5 Otherwise meningococcal disease usually has been considered to be rare among travelers (Figure 2). 6 A single retrospective survey has attempted to quantify the risk of meningococcal disease among international travelers originating in industrialized countries. 7Health authorities in 56 of 108 contacted countries (51.9%) completed questionnaires concerning reported cases of meningococcal disease, and tourism … Corresponding Author: Robert Steffen, MD, ZRM/ISPM, Hirschengraben 84/E29, CH‐8001 Zurich, Switzerland. E‐mail: roste{at}ifspm.uzh.ch

Neisseria meningitidis Serogroup X Sequence Type 767 in Turkey

Neisseria meningitidis is a common inhabitant of the nasopharyngeal tracts of healthy humans and is a significant cause of invasive infections such as meningitis in young children and adolescents worldwide (14). N. meningitidis has been classified into 13 serogroups on the basis of antigenic variation of the capsule, but only serogroups A, B, C, Y, and W-135 have commonly caused invasive infections (8). In Turkey, W-135 has been the most frequently reported serogroup since an international outbreak was reported following the annual Hajj seasons in Saudi Arabia in 2000 and 2001 (10). During the years 2003 to 2008, 17 serogroup W-135 strains (from eight meningitis cases) were isolated from Turkish recruits vaccinated with A+C polysaccharide meningococcal vaccine (10-12). We describe here the first meningococcal meningitis case caused by a serogroup X N. meningitidis strain in Turkey. The patient was a 22-year-old male soldier, working in a military unit, who was admitted to the emergency department with complaints of a 1-week history of fever (39°C), cough, and vomiting on 10 January 2010. There was little petechiate rash on his chest and a lower leg. The laboratory evaluation at that time revealed a leukocyte count of 3,700/mm3, a hemoglobin level of 13.4 g/dl, and an erythrocyte sedimentation rate of 5 mm/h. The patient was then admitted to the infectious disease service with a diagnosis of meningococcal meningitis based on the clinical symptoms and results of confirmatory laboratory tests, including blood culture and cerebrospinal fluid analysis. He was given ceftriaxone (4 g/day) for 10 days and then discharged from the hospital in good condition. Oropharyngeal swab specimens were obtained from the patient's close military personnel contacts, and one person was found to be positive for an N. meningitidis serogroup X strain. He was given a single dose of 500 mg ciprofloxacin immediately. Clinical and oropharyngeal swab specimens were inoculated immediately onto BBL-modified Thayer-Martin medium plates (MTM II; Becton Dickinson Microbiology Systems) and Thayer-Martin medium with VCAT selective supplement (SR10B; Oxoid, Hampshire, England). After incubation, suspect colonies were identified by Gram staining and oxidase reactivity testing and the identification was confirmed by the API NH system (bioMerieux) (4). An antibiotic susceptibility test was performed by the Etest method (AB BIODISK, Solna, Sweden) for ciprofloxacin, ceftriaxone, cefotaxime, penicillin, rifampin, and chloramphenicol (3). The strains were susceptible to the antibiotics tested, except penicillin, with a MIC of 0.75 μg/ml. Serogrouping of the meningococcal isolates was performed by a slide agglutination technique as recommended by Difco Laboratories (Detroit, MI). porA variant region sequencing was performed using the standard primers and identified by querying the respective databases hosted at http://neisseria.org. Multilocus sequence typing (MLST) was performed using the standard primers listed at the Neisseria MLST website (http://pubmlst.org/neisseria/). The isolates had the strain designation X: P1.5-1,10-1: sequence type 767 (ST-767) (cc167). ST-767 meningococci have been found previously among N. meningitidis serogroup A and Y strains in Europe and Africa between 1999 and 2008 (http://pubmlst.org/neisseria/). PFGE typing of NheI-digested DNA was performed by a modification of a previously described method (12). The clinical and carrier isolates had the same genotypic pattern. N. meningitidis serogroup X strains were first described in the 1960s and have been isolated from a few cases of invasive meningococcal diseases in North America, Europe, Australia, and China (2, 6, 7). Outbreaks of N. meningitidis serogroup X strains have been reported in Niger (1), western Kenya (13), and northern Ghana (5). N. meningitidis serogroup X strains were reported to be very efficient in colonization among military recruits in the United Kingdom (9). Before May 2009, eight invasive meningococcal disease cases caused by serogroup W-135 were reported in Turkish soldiers who had been vaccinated with A+C polysaccharide meningococcal vaccine; four of these were fatal. Since that time, a quadrivalent meningococcal polysaccharide vaccine (against A/C/Y/W-135) has been successfully introduced into the Turkish recruit expanded immunization program. We describe here the first meningococcal meningitis case caused by a serogroup X strain in our recruits since the introduction of the quadrivalent vaccine. It was reported that repeated mass vaccination in many African countries might have contributed to colonization by and meningococcal diseases due to serogroup X strains and might result in a changed profile of meningococcal disease (5). We suggest that comprehensive conjugate vaccines including X polysaccharides should be developed. In addition, these data highlight the need for further epidemiological surveillance to carefully monitor the pattern of incidence of meningococcal diseases caused by serogroup X strains and to inform future public health strategies.

FDA approves new quadrivalent meningococcal vaccine

Novartis on February 22 announced that FDA approved Menveo, a quadrivalent meningococcal vaccine in which Neisseria meningitidis serogroup A, C, Y, and W-135 oligosaccharides have been conjugated to a Corynebacterium diphtheriae protein. The approval allows the company to market the vaccine as a

Safety and immunogenicity of one dose of MenACWY-CRM, an investigational quadrivalent meningococcal glycoconjugate vaccine, when administered to adolescents concomitantly or sequentially with Tdap and HPV vaccines

This Phase III study evaluates an investigational quadrivalent meningococcal CRM197 conjugate vaccine, MenACWY-CRM (Novartis Vaccines), when administered concomitantly or sequentially with two other recommended adolescent vaccines; combined tetanus, reduced diphtheria and acellular pertussis (Tdap), and human papillomavirus (HPV) vaccine. In this single-centre study, 1620 subjects 11–18 years of age, were randomized to three groups (1:1:1) to receive MenACWY-CRM concomitantly or sequentially with Tdap and HPV. Meningococcal serogroup-specific serum bactericidal assay using human complement (hSBA), and antibodies to Tdap antigens and HPV virus-like particles were determined before and 1 month after study vaccinations. Proportions of subjects with hSBA titres ≥1:8 for all four meningococcal serogroups (A, C, W-135, Y) were non-inferior for both concomitant and sequential administration. Immune responses to Tdap and HPV antigens were comparable when these vaccines were given alone or concomitantly with MenACWY-CRM. All vaccines were well tolerated; concomitant or sequential administration did not increase reactogenicity. MenACWY-CRM was well tolerated and immunogenic in subjects 11–18 years of age, with comparable immune responses to the four serogroups when given alone or concomitantly with Tdap or HPV antigens. This is the first demonstration that these currently recommended adolescent vaccines could be administered concomitantly without causing increased reactogenicity.

Optimizing Protection Against Meningococcal Disease

Neisseria meningitidis is a leading cause of bacterial meningitis and septicemia in the United States. Vaccines directed against meningococcal disease must elicit high and persistent titers of bactericidal antibodies against prevalent meningococcal serogroups and be highly efficacious in preventing meningococcal infection. Currently, 2 quadrivalent (A, C, W-135, Y) vaccines-a polysaccharide meningococcal vaccine and a conjugate meningococcal vaccine-are licensed in the United States. Neither is approved for use in infants or toddlers younger than 2 years of age. Results of studies with an investigational quadrivalent (ACWY) meningococcal CRM(197) glycoconjugate vaccine in infants demonstrate that this vaccine has potential to protect this age group. The availability of an effective vaccine for routine universal infant immunization is particularly important because the incidence of invasive meningococcal disease is greatest in infants for all serogroups and because achievable vaccination rates are much greater for infants and young children than they are for adolescents.

Quadrivalent meningococcal vaccines: Hyporesponsiveness as an important consideration when choosing between the use of conjugate vaccine or polysaccharide vaccine

Regional variations in the incidence and the distribution of serogroups which are responsible of meningococcal disease necessitate multivalent vaccines to ensure broad coverage for travelers. For almost 30 years, this has been provided by quadrivalent polysaccharide vaccine to protect against serogroups A, C, W-135 and Y, but with the advent of quadrivalent conjugate vaccines is there still a case to use the polysaccharide? The well documented hyporesponsiveness induced by polysaccharide vaccines after repeated administration, most clearly observed against serogroup C, suggest that, where available, conjugate vaccines should always be considered ahead of polysaccharide vaccine.

Absence of Neisseria meningitidis from Throat Swabs of Kuwaiti Pilgrims after Returning from the Hajj

Objective: To investigate whether or not Neisseria meningitidis was present in the throat of Kuwaiti pilgrims after returning from the Hajj. Method: Throat swabs were taken from 177 participants 1 week after returning from the Hajj. The participants were asked about: associated medical conditions, meningococcal vaccination status and the intake of ciprofloxacin before leaving Mecca for Kuwait. Results: There was no throat colonization with N. meningitidis on any of the throat swabs. Of the 177 pilgrims, 163 (92%) were vaccinated with meningococcal quadrivalent vaccine before leaving to Saudi Arabia. Ninety-seven of the pilgrims (83%) had received one dose of ciprofloxacin before leaving Mecca. Conclusion: The result showed that vaccination before leaving Kuwait and ciprofloxacin prophylaxis were effective in preventing throat colonization with Neisseria meningitidis.

Immunogenicity and tolerability of a quadrivalent meningococcal glycoconjugate vaccine in children 2–10 years of age

Meningococcal disease incidence is highest in infants, but a significant burden of disease also occurs in children. In this Phase II, single-centre US study, 619 healthy children (2–10 years of age) received one dose of an investigational quadrivalent meningococcal CRM 197-conjugated vaccine (MenACWY-CRM) or a licensed quadrivalent meningococcal polysaccharide vaccine (MPSV4). Immunogenicity was assessed using the serum bactericidal assay with human complement (hSBA) at 1 and 12 months post-vaccination. Local and systemic reactions were recorded for 7 days, all adverse events (AEs) for 1 month, and medically significant and serious AEs (SAEs) for 12 months post-vaccination. For all four serogroups, more MenACWY-CRM recipients achieved an hSBA titre ≥1:4 at 1 month post-vaccination (A: 82%; C: 83%; W-135: 95%; Y: 91%) compared with the group that received MPSV4 (A: 45%; C: 66%; W-135: 71%; Y: 61%); this difference persisted through to 12 months post-vaccination. Both vaccines were well tolerated. In children 2–10 years of age, MenACWY-CRM induced a higher immune response than that of MPSV4, and was well tolerated.