Structural Investigation of Antigens Using Electron Microscopy

Use of the quadrivalent meningococcal vaccine for control of outbreaks has increased in recent years, but the efficacy of meningococcal vaccine during mass vaccination campaigns in US civilian populations has not been assessed. To evaluate the efficacy of the quadrivalent meningococcal vaccine against serogroup C meningococcal disease in a community outbreak setting and to evaluate potentially modifiable barriers to vaccination in an area with persistent meningococcal disease following immunization. Matched case-control study of vaccine efficacy using cases of serogroup C meningococcal disease in persons eligible for vaccination during mass vaccination campaigns. Control patients were matched by neighborhood and age. The control group was used to identify possible barriers to vaccination. Gregg County, Texas, population 106076, from 1993 to 1995. A total of 17 case patients with serogroup C meningococcal disease eligible for vaccine and 84 control patients. Vaccine efficacy and risk factors associated with nonvaccination. Vaccine efficacy among 2- to 29-year-olds was 85% (95% confidence interval, 27%-97%) and did not change in bivariate analyses with other risk factors that were significant in univariate analysis. Among control patients, older age was strongly associated with nonvaccination; vaccination rates for 2- to 4-year-olds, 5- to 18-year-olds, and 19- to 29-year-olds were 67%, 48%, and 20%, respectively (chi2 for linear trend, P=.01). The meningococcal polysaccharide vaccine was effective against serogroup C meningococcal disease in this community outbreak. Although specific barriers to vaccination were not identified, older age was a risk factor for nonvaccination in the target population of 2- to 29-year-olds. In future outbreaks, emphasis should be placed on achieving high vaccination coverage, with special efforts to vaccinate young adults.

Since the introduction of the first meningococcal conjugate vaccines in 1999, remarkable progress has been made in reducing the morbidity and mortality caused by meningococcal disease. Currently, varying meningococcal conjugate vaccines provide protection against serogroups A, C, Y, and W meningococcal disease. A large impact has been seen after vaccine introduction, particularly in the UK after vaccinating all 1-17 year olds. The introduction of serogroup A conjugate vaccine in the meningitis belt has the potential to control epidemics of disease that disproportionately affect this area of the world. Issues remain that require continued vigilance with disease surveillance and frequent reassessment of vaccine strategies. These issues include duration of protection, potential increases in non-vaccine serogroups, and vaccine safety and potential interference with other routine vaccines. Serogroup B meningococcal vaccines are protein-based vaccines, with the first approved in early 2013. Understanding the potential impact of serogroup B vaccines is critical to developing future meningococcal vaccination strategies.

Meningococcal infection (MI) refers to anthroponoses; is an acute infectious disease with an aerosol transmission mechanism, characterized by various forms of the infectious process: from local (nasopharyngitis) and asymptomatic infections to generalized forms of invasive infection with the development of meningococcemia and meningitis. The causative agent of MI is meningococcus (Neisseria meningitidis) that belongs to the pathogen risk group 2. Preventive vaccination against MI is included in the calendar of preventive vaccinations according to epidemic indications. The problem of MI retains a great medical and social significance for Russian health care due to the continuing high rates of associated mortality, disability, high costs of treatment and rehabilitation. Vaccines against five of the six main N. meningitidis serogroups have been registered worldwide. Serogroup X vaccine is under development. Recently, there has been an increase in the heterogeneity of the meningococcal population due to serogroups W, Y, and X. The polysaccharide vaccines developed in Russia have restrictions on their use, and there is no full-cycle production of meningococcal conjugate vaccines in the Russian Federation. Given the above, the development and registration of new vaccines against MI is an urgent task.
 The purpose of this work is to analyze the current state of development of vaccines for MI prevention. Currently, depending on the production technology, the following types of meningococcal vaccines are available: polysaccharide, conjugated, based on outer membrane vesicles (OMV), protein and based on synthetic polysaccharides. Serogroup-targeted meningococcal vaccines are effective in reducing the public health burden of invasive MI. Polysaccharide conjugate and protein/OMV vaccines are among the most promising vaccines for most invasive meningococcal serogroups. In modern conditions, with the progress in technologies for future polysaccharide conjugate vaccines, new opportunities are opening up for the use of such approaches as chemical/enzymatic synthesis, improved characteristics of the carrier protein, and site-specific conjugation. The development of a single vaccine against the main invasive meningococcal serogroups, rather than its individual antigenic variants, does not lose its relevance. It is timely to develop in the near future a vaccine against N. meningitidis serogroup X, which was previously a rare cause of sporadic meningitis, but has caused outbreaks in various African countries in 20062010 and in recent years.

Research and routine survey of meningococcal meningitis on Indonesian hajj pilgrims have been conducted since 1993 until now. This paper consists of several research and routine survey of meningococcal meningitis during 1993 and 2003. The objectives of the test were determining the meningococcal meningitis carrier on hajj pilgrims, determining the serogroup of N. meningitidis and knowing sensitivity of bacteria to several antibiotics. The result showed increasing of meningococcal meningitis carrier in 1993 up to 1996, that was 1.3% - 9,4% respectively. This proportion of meningococcal meningitis carrier in the case groups decreased after given of rifampicin in 1994 and cyprofloxacin in 1997 as a chemoprophilactic. The result of the study in 1997 indiciated that the carrier rate of groups with cyprofloxacin (1.4%) was lower than rifampicin group (1.4%). Most of the isolated bacteria of N. meningitidis in 1996 and 1997 were resistant to rifampicin (sensitivity test was 0-33%). Serogroup B of N. meningitidis were found dominantly between 1993 and 1999, it changed to be serogroup W135 from 2000 to 2003. The changes related with the majority cases of meningococcal meningitis in another countries that caused by serogroup W135. Because of that since 2002, immunization program has given a tetravalen (serogroup ACYW135) meningococcal vaccine to all of Indonesian hajj pilgrims. The carrier of meningococcal meningitis is still found in hajj pilgrims and their contact. More attention must be given, caused of meningococcal meningitis serogroup B vaccine is not available. The further researches are needed especially for subtype of N. meningitidis, effectivity of the drug choice and development of meningococcal meningitis vaccine serogroup B.

MenB-4C (Bexsero; GlaxoSmithKline Biologicals) is a licensed meningococcal vaccine for capsular B strains. The vaccine contains detergent-extracted outer membrane vesicles (dOMV) and three recombinant proteins, of which one is factor H binding protein (FHbp). In previous studies, overexpression of FHbp in native OMV (NOMV) with genetically attenuated endotoxin (LpxL1) and/or by the use of mutant FHbp antigens with low factor H (FH) binding increased serum bactericidal antibody (SBA) responses. In this study, we immunized 13 infant macaques with 2 doses of NOMV with overexpressed mutant (R41S) FHbp with low binding to macaque FH (NOMV-FHbp). Control macaques received MenB-4C (n = 13) or aluminum hydroxide adjuvant alone (n = 4). NOMV-FHbp elicited a 2-fold higher IgG anti-FHbp geometric mean titer (GMT) than MenB-4C (P = 0.003), and the anti-FHbp repertoire inhibited binding of FH to FHbp, whereas anti-FHbp antibodies to MenB-4C enhanced FH binding. MenB-4C elicited a 10-fold higher GMT against strain NZ98/254, which was used to prepare the dOMV component, whereas NOMV-FHbp elicited an 8-fold higher GMT against strain H44/76, which was the parent of the mutant NOMV-FHbp vaccine strain. Against four strains with PorA mismatched to both of the vaccines and different FHbp sequence variants, NOMV-FHbp elicited 6- to 14-fold higher SBA GMTs than MenB-4C (P ≤ 0.0002). Two of 13 macaques immunized with MenB-4C but 0 of 17 macaques immunized with NOMV-FHbp or adjuvant developed serum anti-FH autoantibodies (P = 0.18). Thus, the mutant NOMV-FHbp approach has the potential to elicit higher and broader SBA responses than a licensed group B vaccine that contains wild-type FHbp that binds FH. The mutant NOMV-FHbp also might pose less of a risk of eliciting anti-FH autoantibodies.IMPORTANCE There are two licensed meningococcal capsular B vaccines. Both contain recombinant factor H binding protein (FHbp), which can bind to host complement factor H (FH). The limitations of these vaccines include a lack of protection against some meningococcal strains and the potential to elicit autoantibodies to FH. We immunized infant macaques with a native outer membrane vesicle (NOMV) vaccine with genetically attenuated endotoxin and overproduced mutant FHbp with low binding to FH. The NOMV-FHbp vaccine stimulated higher levels of protective serum antibodies than a licensed meningococcal group B vaccine against five of six genetically diverse meningococcal strains tested. Two of 13 macaques immunized with the licensed vaccine, which contains FHbp that binds macaque FH, but 0 of 17 macaques given NOMV-FHbp or the negative control developed serum anti-FH autoantibodies Thus, in a relevant nonhuman primate model, the NOMV-FHbp vaccine elicited greater protective antibodies than the licensed vaccine and may pose less of a risk of anti-FH autoantibody.

This policy statement provides recommendations for the prevention of serogroup B meningococcal disease through the use of 2 newly licensed serogroup B meningococcal vaccines: MenB-FHbp (Trumenba; Wyeth Pharmaceuticals, a subsidiary of Pfizer, Philadelphia, PA) and MenB-4C (Bexsero; Novartis Vaccines, Siena, Italy). Both vaccines are approved for use in persons 10 through 25 years of age. MenB-FHbp is licensed as a 2- or 3-dose series, and MenB-4C is licensed as a 2-dose series for all groups. Either vaccine is recommended for routine use in persons 10 years and older who are at increased risk of serogroup B meningococcal disease (category A recommendation). Persons at increased risk of meningococcal serogroup B disease include the following: (1) persons with persistent complement component diseases, including inherited or chronic deficiencies in C3, C5-C9, properdin, factor D, or factor H or persons receiving eculizumab (Soliris; Alexion Pharmaceuticals, Cheshire, CT), a monoclonal antibody that acts as a terminal complement inhibitor by binding C5 and inhibiting cleavage of C5 to C5A; (2) persons with anatomic or functional asplenia, including sickle cell disease; and (3) healthy persons at increased risk because of a serogroup B meningococcal disease outbreak. Both serogroup B meningococcal vaccines have been shown to be safe and immunogenic and are licensed by the US Food and Drug Administration for individuals between the ages of 10 and 25 years. On the basis of epidemiologic and antibody persistence data, the American Academy of Pediatrics agrees with the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention that either vaccine may be administered to healthy adolescents and young adults 16 through 23 years of age (preferred ages are 16 through 18 years) to provide short-term protection against most strains of serogroup B meningococcal disease (category B recommendation).

In October 2014, the Food and Drug Administration (FDA) licensed the first serogroup B meningococcal (MenB) vaccine (MenB-FHbp [Trumenba, Wyeth Pharmaceuticals, Inc.]) as a 3-dose series. In January 2015, FDA licensed a second MenB vaccine (MenB-4C [Bexsero, Novartis Vaccines]) as a 2-dose series. Both vaccines were approved for use in persons aged 10-25 years. Following outbreaks of serogroup B meningococcal disease on two college campuses in 2013, both MenB vaccines were granted Breakthrough Therapy designations, which expedites drug development and review by FDA, and were licensed based on accelerated approval regulations. On February 26, 2015, the Advisory Committee on Immunization Practices (ACIP) recommended use of MenB vaccines among certain groups of persons aged ≥10 years who are at increased risk for serogroup B meningococcal disease. This report summarizes information on MenB administration and provides recommendations and guidance for use of these vaccines among persons aged ≥10 years in certain groups who are at increased risk for serogroup B meningococcal disease, and reviews the evidence considered by ACIP to make these recommendations. Recommendations for broader use of MenB vaccines in adolescents and college students will be considered separately by ACIP.

Neisseria meningitidis is a leading cause of bacterial meningitis and sepsis in the US, Europe and in many other parts of the world, including parts of sub-Saharan Africa (known as the African ‘meningitis belt’). There are > 500,000 cases of meningococcal disease annually with an estimated death toll of 135,000 worldwide. Approximately 10 – 15 % of survivors experience significant morbidity in the form of neurological sequelae, including hearing loss, speech disorders, loss of limbs, mental retardation and paralysis. Disease is usually caused by N. meningitidis serogroups A, B, C, Y or W-135. Prevention of meningococcal disease includes isolation, chemoprophylaxis and vaccination with available polysaccharide vaccines. However, the polysaccharide meningococcal vaccines (i.e., A and C; A, C and W-135; or A, C, Y and W-135) initially developed in the 1970s are generally poorly immunogenic in children or require repeated doses and do not produce long-lasting immunity. Conjugate vaccine technology has been very successfully used in childhood vaccines for the prevention of other bacterial meningitis pathogens, including vaccines against Haemophilus influenzae serotype b (Hib) and more recently, the seven- and nine-valent conjugate pneumococcal vaccines. Newly released meningococcal conjugate vaccines against N. meningitidis serogroup C have been highly efficacious in young children and adolescents, with minimal side effects. Conjugate vaccines targeting other important meningococcal serogroups (e.g., N. meningitidis serogroup A, responsible for the large pandemic outbreaks and the majority of disease in sub-Saharan Africa and serogroups Y and W-135) are under development and together with the serogroup C conjugates, have the potential to significantly impact worldwide sporadic and epidemic meningococcal disease. The search for an effective serogroup B meningococcal vaccine remains elusive. This manuscript reviews the conjugate meningococcal vaccines and their potential for meningococcal disease prevention.

The emergence of antimicrobial resistance among several medically important pathogens represents a serious threat to human health globally and necessitates the development of novel therapeutics. Complement forms a key arm of innate immune defenses against invading pathogens. A mechanism of complement evasion employed by many pathogens is binding of complement inhibitors, including factor H (FH), a key downregulator of the alternative pathway. Most FH-binding bacteria engage FH through regions in FH spanned by domains 6 and 7 and/or 18 through 20. We created a chimeric protein that comprised human FH domains 6 and 7 fused to human IgG1 Fc (FH6,7/HuFc) and tested its activity as an immunotherapeutic against Neisseria meningitidis, which binds FH through domains 6 and 7. FH6,7/HuFc bound to meningococci and effectively blocked FH binding to bacteria. FH6,7/HuFc enhanced human C3 and C4 deposition and facilitated complement-mediated killing in a dose-responsive manner; complement activation and killing were classical pathway dependent. To investigate in vivo efficacy, infant Wistar rats were treated intraperitoneally (IP) with different doses of FH6,7/HuFc and challenged 2 h later with serogroup C strain 4243 given IP. At 8 to 9 h after the challenge, the FH6,7/HuFc-treated rats had >100-fold fewer CFU per ml of blood than control animals pretreated with phosphate-buffered saline (PBS) or FH18-20/HuFc, which does not bind to meningococci (P < 0.0001). These data provide proof of concept of the utility of FH/Fc fusion proteins as anti-infective immunotherapeutics. Because many microbes share a common binding region(s) in FH, FH/Fc chimeric proteins may be a promising candidate for adjunctive therapy against drug-resistant pathogens.

Plasma C3d levels as a diagnostic marker for complete complement factor I deficiency

The case for vaccinating against meningitis B

The United States Advisory Committee on Immunization Practices recommends vaccination against meningococcal serogroups A, C, W, and Y for all 11- and 12-year-olds (with a booster dose at age 16) and against meningococcal serogroup B for 16- to 23-year-olds under shared clinical decision making. This study investigated knowledge, attitude, and practices among nurse practitioners and physician assistants regarding meningococcal vaccination. Although nurse practitioners and physician assistants play an important role in discussing and recommending vaccination, knowledge gaps regarding meningococcal disease and vaccination guidelines were identified. Targeted education may promote shared clinical decision making, improving access to meningococcal vaccination.

BackgroundAs a peak in meningococcal disease often occurs during adolescence, meningococcal vaccination programs are available for this age group in various regions across the globe. Quadrivalent meningococcal (MenACWY) conjugate vaccines are being incorporated in an increasing number of programs in response to changing meningococcal serogroup epidemiology. MenACWY-TT (Nimenrix®) is a MenACWY conjugate vaccine available in the European Union and 50 other countries for preventive vaccination of serogroup A, C, W, and Y disease (Figure 1). MenACWY-TT is licensed in some countries as a 2-dose primary series in individuals as young as 6 weeks of age, while a single dose may be given to previously unvaccinated individuals ≥ 6 months of age, adolescents, and adults. Here, we provide an overview of the 3 primary and 5 extension studies evaluating the clinical development of MenACWY-TT in adolescents (Table 1).Figure 1. Global Registration Status of MenACWY-TT (Nimenrix®) in AdolescentsTable 1. Pivotal Clinical Studies of MenACWY-TT (Nimenrix®) Supporting Licensure in AdolescentsMethodsImmunogenicity and safety data from these 8 clinical studies are summarized.ResultsAcross studies, MenACWY-TT antibody responses against all vaccine serogroups were comparable to those of other MenACWY vaccines 1 month post vaccination (Table 1). Antibody responses to MenACWY-TT persisted for up to 10 years in those vaccinated during adolescence. A MenACWY-TT booster given 10 years after primary meningococcal vaccination in early childhood or adolescence elicited robust antibody responses. MenACWY-TT had an acceptable safety profile, with reactogenicity events most commonly reported. Reactogenicity profiles with MenACWY-TT booster were similar to those seen after primary MenACWY-TT.ConclusionThe MenACWY-TT clinical study program demonstrated the immunogenicity and safety of primary and booster dosing in adolescents. Immune responses persisted through 10 years after primary vaccination.FundingPfizer.DisclosuresPaula Peyrani, MD, Pfizer Inc (Employee, Shareholder) Chris Webber, MD, Pfizer Inc (Employee, Shareholder) Cindy Burman, PharmD, Pfizer Inc (Employee, Shareholder) Paul Balmer, PhD, Pfizer Inc (Employee, Shareholder) John L. Perez, MD, MA, Pfizer Inc (Employee, Shareholder)

BackgroundBetween 2015 and 2017 six deaths due to meningitis in the Lombardy Region, Northern Italy, caught the attention of media and increased concern among the population, with a consequent increase in demand for vaccination. Considering the evidence about the impact of media coverage of health issues on public behaviour, this paper investigates the trend of media coverage and internet searches regarding meningitis in the Lombardy Region.MethodsContent analysis of online articles published from January 2015 to May 2017 and analysis of Google Trends were carried out. A codebook was created in order to assess the content of each article analysed, based on six areas: article characteristics, information about meningococcal disease and vaccination, Local Health Authority activities, accuracy of information and tone of the message.ResultsBoth public interest and media attention peaked in December 2016 and January 2017, when the Lombardy Regional Authority changed its policy by offering co-payment to adults with a saving of 50%. The frequency of meningitis coverage decreased after the announcement of policy change. For example, articles containing new information on meningitis or meningococcal vaccine (76 to 48%, p = 0.01) and preventive recommendations (31% down to 10%, p = 0.006) decreased significantly. An alarmist tone appeared in 21% of pre-policy articles that decreased to 5% post-policy (p = 0.03).ConclusionsThe findings suggest a role for the media in fostering public pressure towards health services and policy-makers. A collaboration between Public Health institutions and the media would be beneficial in order to improve communication with the public.

Living-donor kidney transplantation for atypical haemolytic uremic syndrome with pre-emptive eculizumab use.