Investigation of a bacterial meningitis cluster in a refugee settlement, Obongi District, Uganda, March 2023.

On 6 March 2023, Neisseria meningitidis serogroup C was isolated from a cerebral spinal fluid sample from Obongi District, Uganda. This sample was one of many from patients who were presenting with fever, convulsions, and altered consciousness. We investigated to determine the scope of the meningitis cluster, identify risk factors of contracting meningitis, and inform control measures. We reviewed medical records, conducted active community case finding, and conducted key informant interviews in the affected communities to identify cases and factors associated with contracting meningitis. We analysed case data by person, place, and time. Between 22 December 2022 and 1 May 2023, 25 cases with 2 deaths of bacterial meningitis occurred in Palorinya Refugee Settlement, Obongi District. Of these, 4 were laboratory-confirmed with Neisseria meningitidis serogroup C, 6 were probable cases, and 15 were suspected cases. Most (76%) of case-patients were <18 years old with a median age of 12 years (range 1-66 years). None of the case-patients was vaccinated against Neisseria meningitidis serogroup C. Each case-patient was from a different household and there was no epidemiological link between any of the cases. This meningococcal meningitis cluster caused by Neisseria meningitidis serogroup C occurred among non-vaccinated persons mostly aged <18 years in Palorinya Refugee Settlement. We recommended vaccination of at-risk persons.

Expansion of Neisseria meningitidis Serogroup C Clonal Complex 10217 during Meningitis Outbreak, Burkina Faso, 2019.

During January 28-May 5, 2019, a meningitis outbreak caused by Neisseria meningitidis serogroup C (NmC) occurred in Burkina Faso. Demographic and laboratory data for meningitis cases were collected through national case-based surveillance. Cerebrospinal fluid was collected and tested by culture and real-time PCR. Among 301 suspected cases reported in 6 districts, N. meningitidis was the primary pathogen detected; 103 cases were serogroup C and 13 were serogroup X. Whole-genome sequencing revealed that 18 cerebrospinal fluid specimens tested positive for NmC sequence type (ST) 10217 within clonal complex 10217, an ST responsible for large epidemics in Niger and Nigeria. Expansion of NmC ST10217 into Burkina Faso, continued NmC outbreaks in the meningitis belt of Africa since 2019, and ongoing circulation of N. meningitidis serogroup X in the region underscore the urgent need to use multivalent conjugate vaccines in regional mass vaccination campaigns to reduce further spread of those serogroups.

The meningitis outbreak returns to Niger: Concern, efforts, challenges, and recommendations.

Meningitis, a disease that commonly manifests in African meningitis belt, continues to be a public health problem as it is a fatal disease that leave survivors with long-term effects. Most cases of meningitis are due to bacterial and viral infection, although parasites, fungus, cancer, drugs, and immune disorders can rarely cause meningitis. Stiff neck, high temperature, light sensitivity, disorientation, headaches, and vomiting are the most typical symptoms of meningitis. Niger, being in African meningitis belt, has been affected by many meningitis outbreaks. Since 2015, a total of 20,789 cases and 1369 fatalities (CFR 6.6%) have been documented in Niger. In contrast to earlier seasons, the current outbreak of meningitis in Niger exhibits both an increase in the number of cases and a rise in the growth rate. A total of 559 cases of meningitis, including 18 fatalities (overall CFR 3.2%), were reported in the Zinder Region, southeast of Niger, from 1 November 2022 to 27 January 2023, compared to 231 cases reported from 1 November 2021 to 31 January 2022. In the current outbreak, the Neisseria meningitidis serogroup C (NmC) is responsible for the majority of laboratory confirmed cases (104/111; 93.7%). To organize the response to the outbreak, a global team of WHO and other partners, including MSF and UNICEF, has been sent to Niger. Even though there are many challenges in battle against meningitis in Niger, immunization, antibiotics administration and strong disease surveillance are recommended techniques to cope with the current meningitis outbreak in Niger.

Evaluating the effect of targeted strategies as control tools for hypervirulent meningococcal C outbreaks: a case study from Tuscany, Italy, 2015 to 2016.

BackgroundMeningococcus (Neisseria meningitidis) is the causative bacteria of invasive meningococcal disease (IMD), a major cause of meningitis and sepsis. In 2015-16, an outbreak caused by serogroup C meningococci (MenC), belonging to the hyperinvasive strain ST-11(cc-11), resulted in 62 IMD cases in the region of Tuscany, Italy.AimWe aimed to estimate the key outbreak parameters and assess the impact of interventions used in the outbreak response.MethodsWe developed a susceptible-carrier-susceptible individual-based model of MenC transmission, accounting for transmission in households, schools, discos/clubs and the general community, which was informed by detailed data on the 2015-16 outbreak (derived from epidemiological investigations) and on the implemented control measures.ResultsThe outbreak reproduction number (Re) was 1.35 (95% prediction interval: 1.13-1.47) and the IMD probability was 4.6 for every 1,000 new MenC carriage episodes (95% confidence interval: 1.8-12.2). The interventions, i.e. chemoprophylaxis and vaccination of close contacts of IMD cases as well as age-targeted vaccination, were effective in reducing Re and ending the outbreak. Case-based interventions (including ring vaccination) alone would have been insufficient to achieve outbreak control. The definition of age groups to prioritise vaccination had a critical impact on the effectiveness and efficiency of control measures.ConclusionsOur findings suggest that there are no effective alternatives to widespread reactive vaccination during outbreaks of highly transmissible MenC strains. Age-targeted campaigns can increase the effectiveness of vaccination campaigns. These results can be instrumental to define effective guidelines for the control of future meningococcal outbreaks caused by hypervirulent strains.

Intranasal and Intramuscular Immunization with Outer Membrane Vesicles from Serogroup C Meningococci Induced Functional Antibodies and Immunologic Memory.

BACKGROUND: Immunization is the key to prevent invasive meningococcal disease (IMD), caused by Neisseria meningitidis. Outer membrane vesicles (OMVs) can be used as meningococcal antigens. METHODS: Isogenic mice A/Sn (H2a) were immunized with low antigenic doses of OMVs of an N. meningitidis C:2a:P1.5 strain, via intranasal/intramuscular route, adjuvanted by cholera toxin subunit B (CTB) or via intramuscular route only, adjuvanted by aluminium hydroxide (AH). Mice were followed until old age and humoral and cellular responses were assessed by ELISA, Immunoblotting, Dot-blot, Serum-bactericidal assay, Immunohistochemistry and ELISpot. RESULTS: OMV+CTB and OMV+AH groups presented statistically higher antibodies titers, which persisted until middle and old ages. IgG isotypes point to a Th2 type of response. Avidity indexes were considered high, regardless of adjuvant use, but only groups immunized with OMVs and adjuvants (OMV+CTB and OMV+AH) presented bactericidal activity. The antibodies recognized antigens of molecular weights attributed to porin and cross-reactivity proteins. Although the spleen of old mice did not present differences in immunohistochemistry marking of CD68+, CD4+, CD79+ and CD25+ cells, splenocytes of immune groups secreted IL-4 and IL-17 when stimulated with OMVs and meningococcal C polysaccharide. CONCLUSION: We concluded that both adjuvants, CTB and AH, improved the immunogenicity of low doses of OMVs and contributed to a persistent immune response. Even though AH is well established in the vaccinology area, CTB seems to be a promising adjuvant candidate for meningococcal vaccines: it is suitable for mucosal delivery and supports a Th2 type of response. Therefore, OMVs are still a relevant vaccine platform.

Comparing the meningococcal serogroup C immune response elicited by a tetanus toxoid conjugate quadrivalent meningococcal vaccine (MenACYW-TT) versus a quadrivalent or monovalent C tetanus toxoid conjugate meningococcal vaccine in healthy meningococcal vaccine-naïve toddlers: A randomised, controlled trial.

MenACYW-TT (MenQuadfi®) is a quadrivalent meningococcal tetanus toxoid conjugate vaccine licensed in Europe for use in individuals ≥12 months. This study assessed whether serogroup C immune responses with MenACYW-TT were at least non-inferior, or superior, to those of quadrivalent meningococcal ACWY (MCV4-TT; Nimenrix®) and monovalent meningococcal C (MenC-TT; NeisVac-C®) vaccines in toddlers (12-23 months). In this modified, double-blind Phase III study (NCT03890367), 701 toddlers received one dose of MenACYW-TT (n = 230), MCV4-TT (n = 232) or MenC-TT (n = 239). Serum bactericidal assays with human (hSBA) and baby rabbit (rSBA) complement were used to measure anti-meningococcal serogroup C antibodies at baseline and 30 days post-vaccination. A sequential statistical approach was used for primary and secondary objectives. For the primary objectives, superiority of serogroup C was assessed in terms of hSBA seroprotection rates (defined as titers ≥1:8) and GMTs for MenACYW-TT compared to MCV4-TT, and rSBA GMTs compared to MenC-TT. The safety of all vaccines within 30 days post-vaccination was described. When administered as a single dose to meningococcal vaccine-naïve healthy toddlers the superiority of the MenACYW-TT serogroup C immune response versus MCV4-TT was demonstrated for hSBA GMTs (ratio 16.3 [12.7-21.0]) and seroprotection (difference 10.43% [5.68-16.20]); and versus MenC-TT in terms of rSBA GMTs (ratio 1.32 [1.06-1.64]). The safety profiles of a single dose of MenACYW-TT, MCV4-TT and MenC-TT were similar. In meningococcal vaccine-naïve toddlers, MenACYW-TT induced superior immune responses to serogroup C versus MCV4-TT in terms of hSBA seroprotection and GMTs and versus MenC-TT in terms of rSBA GMTs.

Seroprevalence of meningococcal ACWY antibodies across the population in the Netherlands: Two consecutive surveys in 2016/17 and 2020.

BACKGROUND: Meningococcal serogroup C (MenC) vaccination was introduced for 14-month-olds in the Netherlands in 2002, alongside a mass campaign for 1-18 year-olds. Due to an outbreak of serogroup W disease, MenC vaccination was replaced for MenACWY vaccination in 2018, next to introduction of a booster at 14 years of age and a catch-up campaign for 14-18 year-olds. We assessed meningococcal ACWY antibodies across the Dutch population in 2016/17 and 2020. METHODS: In a nationwide cross-sectional serosurvey in 2016/17, sera from participants aged 0-89 years (n = 6886) were tested for MenACWY-polysaccharide-specific (PS) serum IgG concentrations, and functional MenACWY antibody titers were determined in subsets. Moreover, longitudinal samples collected in 2020 (n = 1782) were measured for MenACWY-PS serum IgG concentrations. RESULTS: MenC antibody levels were low, except in recently vaccinated 14-23 month-olds and individuals who were vaccinated as teenagers in 2002, with seroprevalence of 59% and 20-46%, respectively. Meningococcal AWY antibody levels were overall low both in 2016/17 and in 2020. Naturally-acquired MenW immunity was limited in 2020 despite the recent serogroup W outbreak. CONCLUSIONS: This study demonstrates waning of MenC immunity 15 years after a mass campaign in the Netherlands. Furthermore, it highlights the lack of meningococcal AWY immunity across the population and underlines the importance of the recently introduced MenACWY (booster) vaccination.

Vaccine Impact and Effectiveness of Meningococcal Serogroup ACWY Conjugate Vaccine Implementation in the Netherlands: A Nationwide Surveillance Study.

BACKGROUND: In response to the recent serogroup W invasive meningococcal disease (IMD-W) epidemic in the Netherlands, meningococcal serogroup C (MenC) conjugate vaccination for children aged 14 months was replaced with a MenACWY conjugate vaccination, and a mass campaign targeting individuals aged 14-18 years was executed. We investigated the impact of MenACWY vaccination implementation in 2018-2020 on incidence rates and estimated vaccine effectiveness (VE). METHODS: We extracted IMD cases diagnosed between July 2014 and December 2020 from the national surveillance system. We calculated age group-specific incidence rate ratios by comparing incidence rates before (July 2017-March 2018) and after (July 2019-March 2020) MenACWY vaccination implementation. We estimated VE in vaccine-eligible cases using the screening method. RESULTS: Overall, the IMD-W incidence rate declined by 61% (95% confidence interval [CI], 40 to 74). It declined by 82% (95% CI, 18 to 96) in the vaccine-eligible age group (individuals aged 15-36 months and 14-18 years) and by 57% (95% CI, 34 to 72) in vaccine-noneligible age groups. VE was 92% (95% CI, -20 to 99.5) in vaccine-eligible toddlers (aged 15-36 months). No IMD-W cases were reported in vaccine-eligible teenagers after the campaign. CONCLUSIONS: The MenACWY vaccination program was effective in preventing IMD-W in the target population. The IMD-W incidence reduction in vaccine-noneligible age groups may be caused by indirect effects of the vaccination program. However, disentangling natural fluctuation from vaccine effect was not possible. Our findings encourage the use of toddler and teenager MenACWY vaccination in national immunization programs.

NMR characterization of a multi-valent conjugate vaccine against Neisseria meningitidis A, C, W, Y and Haemophilus influenzae b infections.

Physicochemical technologies are a powerful tool for the structural characterization of vaccine antigens both at bulk level as well as on the final formulation. High-field Nuclear Magnetic Resonance (NMR) spectroscopy has been found to be an extremely and robust tool for tracking the industrial process manufacturing of carbohydrate-based vaccines. I have applied NMR spectroscopy to the characterization of a penta-valent conjugate vaccine against Neisseria meninigitidis group A, C, W, Y (MenACWY) and Haemophilus influenzae type b (Hib) infections, constituted of capsule derived polysaccharide fragments independently conjugated to CRM197 protein carrier (CRM-MenA, CRM-MenC, CRM-MenW, CRM-MenY, CRM-Hib). 1H NMR has been used for the identity testing of the carbohydrate antigens and of the vaccine formulation. The application of NMR-based assays on multivalent conjugate vaccines looks to be a promising approach for identity and stability analyses useful for future vaccines development.

Seroprevalence of meningococcal serogroup C bactericidal antibodies in the Portuguese population, a decade after vaccine introduction in the National Immunisation Programme.

BACKGROUND: The incidence of invasive meningococcal disease due to serogroup C (MenC) decreased in Portugal since the introduction of the conjugate vaccine (MCC) in the free market in 2001 and in the National Immunisation Plan in 2006. Considering the potential waning of the antibody response reported in the literature, the different vaccination schemes that were used in our country over the past decade, and that Neisseria meningitidis serogroup C continues to circulate, the Portuguese population may currently be at increased risk of infection. In the absence of national data, we evaluated the seroprotection level of the Portuguese population against MenC, in order to identify the protected fraction of the population and ponder on the necessity of a booster dose of the MCC vaccine. METHODS: We measured serum bactericidal antibody levels against MenC in a representative sample of the population (n = 1500) aged 2-64 years who participated in the 2015/2016 National Serological Survey. RESULTS: A total of 31.1% (466/1500, 95%CI: 29-33%) of the individuals studied were protected against MenC. The geometric mean titre was 6.5. The proportion of seroprotected was particularly low in children aged 2-4 years (<16%) who received a single dose of the vaccine at 12 months of age (vaccination strategy since 2012). The proportion of seroprotected was higher (44.7% to 53.5%) in adolescent and young adults (15-24 years of age), resulting from vaccination during the catch-up campaign at 5-15 years of age. The highest protection rates were observed when the vaccine was administered during adolescence. CONCLUSION: The small fraction of population seroprotected, combined with the already known waning effect of the antibody response over time, may indicate that the Portuguese population will become progressively more exposed to the risk of infection. Taking in consideration our results, we recommend to change the current vaccination strategy and introduce a booster dose of the MCC vaccine during adolescence.

Meningococcal carriage in periods of high and low invasive meningococcal disease incidence in the UK: comparison of UKMenCar1-4 cross-sectional survey results.

BACKGROUND: The incidence of invasive meningococcal disease in the UK decreased by approximately four times from 1999 to 2014, with reductions in serogroup C and serogroup B disease. Lower serogroup C invasive meningococcal disease incidence was attributable to implementation of the meningococcal serogroup C conjugate vaccine in 1999, through direct and indirect protection, but no vaccine was implemented against serogroup B disease. UK Meningococcal Carriage surveys 1-3 (UKMenCar1-3), conducted in 1999, 2000, and 2001, were essential for understanding the impact of vaccination. To investigate the decline in invasive meningococcal disease incidence, we did a large oropharyngeal carriage survey in 2014-15, immediately before the changes to meningococcal vaccines in the UK national immunisation schedule. METHODS: UKMenCar4 was a cross-sectional survey in adolescents aged 15-19 years who were enrolled from schools and colleges geographically local to one of 11 UK sampling centres between Sept 1, 2014, and March 30, 2015. Participants provided an oropharyngeal swab sample and completed a questionnaire on risk factors for carriage, including social behaviours. Samples were cultured for putative Neisseria spp, which were characterised with serogrouping and whole-genome sequencing. Data from this study were compared with the results from the UKMenCar1-3 surveys (1999-2001). FINDINGS: From the 19 641 participants (11 332 female, 8242 male, 67 not stated) in UKMenCar4 with culturable swabs and completed risk-factor questionnaires, 1420 meningococci were isolated, with a carriage prevalence of 7·23% (95% CI 6·88-7·60). Carriage prevalence was substantially lower in UKMenCar4 than in the previous surveys: carriage prevalence was 16·6% (95% CI 15·89-17·22; 2306/13 901) in UKMenCar1 (1999), 17·6% (17·05-18·22; 2873/16 295) in UKMenCar2 (2000), and 18·7% (18·12-19·27; 3283/17 569) in UKMenCar3 (2001). Carriage prevalence was lower for all serogroups in UKMenCar4 than in UKMenCar1-3, except for serogroup Y, which was unchanged. The prevalence of carriage-promoting social behaviours decreased from 1999 to 2014-15, with individuals reporting regular cigarette smoking decreasing from 2932 (21·5%) of 13 650 to 2202 (11·2%) of 19 641, kissing in the past week from 6127 (44·8%) of 13 679 to 7320 (37·3%) of 19 641, and attendance at pubs and nightclubs in the past week from 8436 (62·1%) of 13 594 to 7662 (39·0%) of 19 641 (all p<0·0001). INTERPRETATION: We show that meningococcal carriage prevalence in adolescents sampled nationally during a low incidence period (2014-15) was less than half of that in an equivalent population during a high incidence period (1999-2001). Disease and carriage caused by serogroup C was well controlled by ongoing vaccination. The prevalence of behaviours associated with carriage declined, suggesting that public health policies aimed at influencing behaviour might have further reduced disease. FUNDING: Wellcome Trust, UK Department of Health, and National Institute for Health Research.

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. Infants were randomly assigned (1:1) with permuted block randomisation to receive a 2 + 1 (2, 4, and 12 months; group 1) or 1 + 1 (3 and 12 months; group 2) schedule of the 13-valent pneumococcal conjugate vaccine (PCV13). All infants also received 4CMenB at 2, 4, and 12 months of age, and had blood samples taken at 5 and 13 months. Participants and clinical trial staff were not masked to treatment allocation. Proportions of participants with human complement serum bactericidal antibody (hSBA) titres of at least 4 were determined for group B meningococcus (MenB) reference strains 5/99 (Neisserial Adhesin A [NadA]), NZ98/254 (porin A), and 44/76-SL (factor H binding protein [fHbp]). Geometric mean titres (GMTs) with 95% CIs were also calculated, and concomitant vaccine responses (group C meningococcus [MenC], Haemophilus influenzae b [Hib], tetanus, diphtheria, and pertussis) were compared between groups. The primary outcome was PCV13 immunogenicity, with 4CMenB immunogenicity and reactogenicity as secondary outcomes. All individuals by randomised group with a laboratory result were included in the analysis. The study is registered on the EudraCT clinical trials database, 2015-000817-32, and ClinicalTrials.gov, NCT02482636, and is complete. FINDINGS: Between Sept 22, 2015, and Nov 1, 2017, of 376 infants screened, 213 were enrolled (106 in group 1 and 107 in group 2). 204 samples post-primary immunisation and 180 post-boost were available for analysis. The proportion of participants with hSBA of at least 4 was similar in the two study groups. For strain 5/99, all participants developed hSBA titres above 4 in both groups and at both timepoints. For strain 44/76-SL, these proportions were 95·3% (95% CI 88·5-98·7) or above post-priming (82 of 86 participants in group 1), and 92·4% (84·2-97·2) or above post-boost (73 of 79 participants in group 1). For strain NZ98/254, these proportions were 86·5% (78·0-92·6) or above post-priming (83 of 96 participants in group 2) and 88·6% (79·5-94·7) or above post-boost (70 of 79 participants in group 1). The MenC rabbit complement serum bactericidal antibody (rSBA) titre in group 1 was significantly higher than in group 2 (888·3 vs 540·4; p=0·025). There was no significant difference in geometric mean concentrations between groups 1 and 2 for diphtheria, tetanus, Hib, and pertussis post-boost. A very small number of children did not have a protective response against 44/76-SL and NZ98/254. Local and systemic reactions were similar between the two groups, apart from the 3 month timepoint when one group received an extra dose of PCV13 and recorded more systemic reactions. INTERPRETATION: These data support the recent change to the licensed European schedule for 4CMenB to add an infant 2 + 1 schedule, as used in the routine UK vaccine programme with an effectiveness of 59·1%. When compared with historical data, our data do not suggest that effectiveness would be higher with a 3 + 1 schedule, however a suboptimal boost response for bactericidal antibodies against vaccine antigen fHbp suggests a need for ongoing surveillance for vaccine breakthroughs due to fHbp-matched strains. Changing from a 2 + 1 to a 1 + 1 schedule for PCV13 for the UK is unlikely to affect protection against diphtheria, tetanus, and Hib, however an unexpected reduction in bactericidal antibodies against MenC seen with the new schedule suggests that ongoing surveillance for re-emergent MenC disease is important. FUNDING: Bill & Melinda Gates Foundation and the National Institute for Health Research.

Gene flow and Bayesian phylogeography of serogroup C meningococci circulating in Italy.

INTRODUCTION: Hyperinvasive strains of Neisseria meningitidis serogroup C have caused outbreaks of severe disease in Italy. Here, we report the analysis of the migration patterns of C:P1.5-1,10-8:F3-6:ST-11(cc11) meningococcal strains from different Italian regions collected between 2012 and 2017. METHODS: N. meningitidis genomes were sequenced through the whole genome sequencing (WGS) method and were analyzed using the BIGSdb Genome Comparator tool. The phylogeography was performed using BEAST. The gene flows in Italy were tested by using MacClade. RESULTS: The C:P1.5-1,10-8:F3-6:ST-11(cc11) hyperinvasive meningococcal strain, for the data available at the time of the analysis, from UK reached at first Emilia Romagna region, and then, in 2012, was detected in the outbreak occurred in the port of Livorno. The "Tuscany-outbreak strain" was likely introduced in Italy between 2013 and 2014. Most of the observed gene flow events occurred from the Center to Northern part of Italy. DISCUSSION: The phylogeographic analysis allowed to track the dissemination of C:P1.5-1,10-8:F3-6:ST-11(cc11) strains in the country.

Enfermedad meningocócica invasiva por serogrupo C en la era posvacunal y fallos vacunales / Serogroup C invasive meningococcal disease in the post-vaccine era and vaccine failures

INTRODUCCIÓN: La incidencia de la enfermedad meningocócica invasiva (EMI) por serogrupo C ha disminuido desde la introducción de la vacunación sistemática el año 2000. El objetivo de este estudio es determinar los casos de EMI diagnosticados desde entonces y los fallos vacunales en los casos por serogrupo C. PACIENTES Y MÉTODOS: Análisis retrospectivo de pacientes diagnosticados de EMI confirmada por cultivo o reacción en cadena de la polimerasa, en un hospital infantil de tercer nivel de Barcelona, entre 2001 y 2018. Se analizó el número de dosis de vacuna recibidas y la edad, recogidos de la historia clínica y del carnet de vacunaciones. RESULTADOS: Se confirmaron 128 casos de EMI (7,1 casos/año; 70,3% en < 5 años). Se estudió el serogrupo en 125 casos (97,6%): 103 fueron B (82,4%), 10 fueron C (8%), uno fue 29E (0,8%) y uno fue Y (0,8%); solo 10 (8%) no fueron serogrupables. De los 10 pacientes con serogrupo C, 4 no estaban vacunados y en 3 la pauta fue incompleta en cuanto a número de dosis; 3 de ellos recibieron la pauta completa según la edad y el calendario vacunal vigente, por lo que se consideran fallos vacunales. Fallecieron 6 pacientes (tasa de letalidad: 4,7%): 5 por serogrupo B (letalidad: 4,8%) y uno por serogrupo C (letalidad: 10%). CONCLUSIONES: El serogrupo C representó solo el 8% de los casos de EMI en el periodo de estudio y los fallos vacunales de este serogrupo fueron del 30%

INTRODUCTION: The incidence of serogroup C invasive meningococcal disease (IMD) has decreased since the introduction of systematic vaccination in 2000. The aim of this study is to determine the number of serogroup C IMD cases diagnosed since then and the vaccine failures. PATIENTS AND METHODS: A retrospective analysis was performed on patients diagnosed with IMD by culture or polymerase chain reaction (PCR) in a maternity and childhood hospital in Barcelona between 2001 and 2018. An analysis was made of the number of vaccine doses and the age received, as well as on the medical records and vaccine cards. RESULTS: There were 128 confirmed cases of IMD (7.1 cases/year; 70.3 in < 5 years). The serogroup was studied in 125 (97.6%) cases, in which 103 (82.4%) were B, 10 (8%) were C, one (0.8%) was 29E, and one (0.8%) was Y, and only 10 (8%) were not able to be serogrouped. Of the 10 patients with serogroup C, 4 were not vaccinated, and in 3, the course was not complete as regards the number of doses. The other 3 received the complete course according to age and current calendar, and thus were considered vaccine failures. A total of 6 patients died (mortality rate: 4.7%), 5 due to serogroup B (mortality: 4.8%), and one due to serogroup C (mortality: 10%). CONCLUSIONS: Serogroup C only represented 8% of IMD cases in the period studied, with 30% of cases due to this serogroup being vaccine failures

An Update on Meningococcal Vaccination.

Neisseria meningitidis bacterial infection can cause severe life-threatening meningitis. Individuals who survive may be left with profound sequelae. In epidemic regions such as the meningitis belt of Africa, the case rate is drastically higher than in nonepidemic regions and is due to distinct outbreak serogroups. Two highly effective conjugate meningococcal vaccine against serogroups A, C, W and Y are licensed and indicated for prevention in childhood vaccination schedules and for travelers to outbreak regions. In the US, meningococcus serogroup B is the main cause of outbreaks, in areas with crowding such as college dorms. It has taken over 40 years to develop a meningitis type B vaccine and now there are 2 brands available for children and teens. All college-bound individuals should complete schedules of both conjugate ACWY serotypes and meningitis B vaccine series. This paper reviews details on who to vaccinate and how to use the currently available meningococcal meningitis vaccines.

Long-term impacts of MenC vaccination campaign in the Salvador, Brazil metropolitan region: A comparison of pre- and post-vaccine periods.

The Meningococcal Serogroup C Conjugate Vaccine (MenC) was introduced into the Brazilian Immunization Program in 2010. However, in Salvador, the fourth largest capital in Brazil, an extended catch-up campaign was conducted earlier in that year, which focused on adolescents and young adults aged 10-24 years. To evaluate the long-term impact of MenC vaccination, we analyzed hospital-based surveillance data on cases of meningococcal disease in the Salvador metropolitan region during the pre-vaccine (2005-2009) and post-vaccine (2011-2016) campaign periods. Six years after the introduction of the MenC vaccine, the mean incidence rate decreased from 3.20 to 0.93 cases per 100,000 individuals (71% reduction, 95% CI [58.7-83.3]) in children <4 years. Reductions of 25.6% and 21.1% were also observed for the age groups of 5-9 and 10-14 years, respectively. On the other hand, incidence increased in the 15-24-year age group from 0.72 to 1.11, and from 0.31 to 0.60 in individuals aged >25 years (p < 0.05). At the end of the study period, serogroup C was the most prevalent (65.7%), followed by serogroups B (9.8%), W (2.3%), Y (1.6%) and A (1.0%); serogrouping was not possible in 19.6% of the cases, or adequate material was not available for serogroup identification. The use of real-time PCR from 2010 onwards increased detection rates of meningococcal meningitis by 29.6%. The long-term impact of the MenC vaccination campaign was associated with a significant reduction in MenC disease in children aged 0-4 years, yet no effect was observed in adolescents and adults, as evidenced by increasing trends in infection rates. In addition, the emergence of meningococcal serogroup A was identified, which should serve as an alert to public health officials and deserves further investigation.

[Serogroup C invasive meningococcal disease in the post-vaccine era and vaccine failures]. / Enfermedad meningocócica invasiva por serogrupo C en la era posvacunal y fallos vacunales.

INTRODUCTION: The incidence of serogroup C invasive meningococcal disease (IMD) has decreased since the introduction of systematic vaccination in 2000. The aim of this study is to determine the number of serogroup C IMD cases diagnosed since then and the vaccine failures. PATIENTS AND METHODS: A retrospective analysis was performed on patients diagnosed with IMD by culture or polymerase chain reaction (PCR) in a maternity and childhood hospital in Barcelona between 2001 and 2018. An analysis was made of the number of vaccine doses and the age received, as well as on the medical records and vaccine cards. RESULTS: There were 128 confirmed cases of IMD (7.1 cases/year; 70.3 in <5 years). The serogroup was studied in 125 (97.6%) cases, in which 103 (82.4%) were B, 10 (8%) were C, one (0.8%) was 29E, and one (0.8%) was Y, and only 10 (8%) were not able to be serogrouped. Of the 10 patients with serogroup C, 4 were not vaccinated, and in 3, the course was not complete as regards the number of doses. The other 3 received the complete course according to age and current calendar, and thus were considered vaccine failures. A total of 6 patients died (mortality rate: 4.7%), 5 due to serogroup B (mortality: 4.8%), and one due to serogroup C (mortality: 10%). CONCLUSIONS: Serogroup C only represented 8% of IMD cases in the period studied, with 30% of cases due to this serogroup being vaccine failures.