Research progress on immunogenicity evaluation of serogroup B meningococcal vaccine / 中华预防医学杂志

Epidemic cerebrospinal meningitis (meningococcal meningitis) is an acute respiratory infectious disease with high mortality and serious sequelae. Meningococcal vaccine is an effective measure to prevent and control meningococcal meningitis. At present, group B meningococcal meningitis has become the main prevalent serum group in the world, including China. Meningococcal ACYW and other vaccines are mainly composed of capsular polysaccharides, while the main component of group B meningococcal vaccine is protein, including outer membrane vesicles (OMV) and recombinant protein vaccine. The methods for evaluating the immunogenicity of group B meningococcal vaccine include hSBA and alternative methods such as meningococcal antigen typing system (MATS), flow cytometric meningococcal antigen surface expression assay (MEASURE), genetic meningococcal antigen typing system (gMATS) and bexsero antigen sequence type (BAST). The evaluation of vaccine immunogenicity is the basis of vaccine development and clinical trial research, However, at present, there is no group B meningococcal vaccine in China. Therefore, in this paper, the research progress of immunogenicity evaluation of group B meningococcal vaccine has been reviewed, in order to provide technical guidance for the research and development of group B meningococcal vaccine, immunogenicity evaluation and clinical trial research in China.

Carriage prevalence of Neisseria meningitidis in the Americas in the 21st century: a systematic review

Abstract Neisseria meningitidis is a bacterium that colonizes the human nasopharynx and is transmitted by respiratory droplets from asymptomatic or symptomatic carriers. Occasionally, the pathogen invades the mucosa and enters the bloodstream, causing invasive meningococcal disease, a life-threatening infection. While meningococcal colonization is the first step in the development of invasive disease, the risk factors that predict progression from asymptomatic to symptomatic status are not well-known. The present report aimed to describe the prevalence of N. meningitidis carriers throughout the Americas, emphasizing the risk factors associated with carrier status, as well as the most prevalent serogroups in each studied population. We conducted a systematic review by searching for original studies in the MEDLINE/PubMed, Embase, LILACS and SciELO databases, published between 2001 and 2018. Exclusion criteria were articles published in a review format, case studies, case control studies, investigations involving animal models, and techniques or publications that did not address the prevalence of asymptomatic carriers in an American country. A total of 784 articles were identified, of which 23 were selected. The results indicate that the highest prevalence rates are concentrated in Cuba (31.9%), the United States (24%), and Brazil (21.5%), with increased prevalence found among adolescents and young adults, specifically university students and males. The present systematic review was designed to support epidemiological surveillance and prevention measures to aid in the formulation of strategies designed to control the transmission of meningococci in a variety of populations and countries throughout the Americas.

Estudio de tolerancia local de la vacuna antimeningocóccica VA-MENGOC-BC® en ratas Sprague Dawley. Evaluación a los 24 y 36 meses en estante / Local tolerance study of the VA-MENGOC-BC® antimeningococcal vaccine in Sprague Dawley rats. Evaluation at 24 and 36 months of shelf

La meningitis meningocóccica continua siendo un problema de salud en diferentes países y para la prevención de esta enfermedad se han obtenido diferentes vacunas. La vacuna VA-MENGOC-BC® ha constituido ser eficaz y segura en la prevención de la meningitis meningocóccica contra los serogrupos B y C. Esta ha demostrado buena estabilidad en el tiempo sin cambiar su calidad como producto; fue conservada a estante durante 24 y 36 meses a temperaturas de 4 a 8 °C. Se evaluó su posible potencial toxicológico a través de un estudio de tolerancia local en ratas Sprague Dawley para extender su vida útil. Los animales inmunizados se observaron diariamente para evaluar síntomas locales y sistémicos de toxicidad. Se realizaron evaluaciones del peso corporal, consumo de agua y alimento, termometría, musculometría e irritabilidad dérmica por el método de Draize. Se realizaron estudios anatomopatológicos periódicos para observar posibles efectos adversos. No se observaron síntomas de toxicidad ni muertes. No se encontraron diferencias entre los grupos experimentales en cuanto al peso corporal, el consumo de agua y de alimentos, no se evidenció fiebre, ni irritabilidad local. Anatomopatológicamente a nivel del punto de inoculación se observaron procesos granulomatosos de tipo macrofágicos característicos en las vacunas que contienen hidróxido de aluminio. Estos resultados permitieron concluir que la vacuna VA-MENGOC-BC® que permaneció en estante durante 24 y 36 meses no evidenció efectos adversos locales, ni sistémicos en las ratas(AU)

Meningococcal meningitis continues to be a health problem in different countries and different vaccines have been obtained for the prevention of this disease. VA-MENGOC-BC® vaccine has been effective and safe in the prevention of meningococcal meningitis against serogroups B and C. This has shown good stability over time without changing its quality as a product; it was stored on a shelf for 24 and 36 months at temperatures of 4 to 8 °C. Their possible toxicological potential was evaluated through a local tolerance study in Sprague Dawley rats. Immunized animals were observed daily to evaluate local and systemic toxicity symptoms. Body weight, water and feed intake, thermometry, musculometry were performed and dermal irritability by the Draize method. Anatomopathological studies to observe possible adverse effects were made. No symptoms of toxicity or deaths were observed. No differences were found between the experimental groups in terms of body weight, water and food consumption, no fever or local irritability was evident. Anatomopathologically no lesions of diagnostic value were observed, at the site of inoculation, granulomatous processes of macrophagic type characteristic in vaccines containing aluminum hydroxide were observed. These results allowed us to conclude that the VA-MENGOC-BC® vaccine that remained on the shelf for 24 and 36 months did not show any local or systemic effects in rats(AU)

Invasive meningococcal disease / Doenca meningococica invasiva

Invasive meningococcal disease (IMD) is a major public health and continues to cause substantial mortality and morbidity. Serotype C is the most frequent in Brazil. The clinical spectrum of IMD is broad (meningitis, meningococcemia or both) and the clinical evolution may be unpredictable. Main features associated with mortality are: age higher than 50 years old, seizures, shock, and meningococcemia without meningitis. Blood cultures should be obtained immediately. Lumbar puncture can be performed without previous computed tomography scan (CT) in most cases. Clinical features can be useful to predic patients where an abnormal CT scan is likely. Cerebrospinal fluid (CSF) culture and Gram stain should always be required. Latex agglutination sensitivity is highly variable. Polymerase chain reaction is specially useful when other methods are negative or delayed. Usually ceftriaxone should not be delayed while awaiting CSF study or CT. Dexamethasone can be used in meningococcal meningitis. Early suspicion of IMD and antibiotic in primary care before hospitalization, rapid transportation to a hospital, and stabilization in an intensive-care unit has substantially reduced the case-fatality rate. Vaccines against serotypes A, C, W-135, and Y are available while vaccines against serotype B are expected.

A doença meningocócica invasiva (DMI) é um problema de saúde pública e continua causando importante mortalidade e morbidade. O sorotipo C é o mais frequente no Brazil. O espectro clínico da DMI é amplo (meningite, meningococcemia ou ambos) e a evolução clínica pode ser imprevisível. As principais características associadas a mortalidade são: idade acima de 50 anos, convulsões, choque, e meningococcemia sem meningite. Culturas de sangue devem ser obtidas imediatamente. Punção lombar pode ser realizada sem tomografia computadorizada (TC) prévia na maioria dos casos. Características clínicas podem ajudar a predizer pacientes com elevada probabilidade de apresentar TC alterada. Cultura e Gram no líquido cefalorraquiano devem ser sempre solicitadas. Aglutinação do látex apresenta sensibilidade muito variável. Reação em cadeia da polimerase é especialmente útil quando os outros métodos são negativos ou demorados. O uso de ceftriaxona não deve ser retardado enquanto se esperam os resultados do líquor ou TC. Dexametasona pode ser utilizada na meningite meningococóca. Suspeita precoce de DMI, antibiótico no primeira atendimento, antes da admissão hospitalar, transporte rápido para hospital, e estabilização em unidade de terapia intensiva reduz substancialmente a taxa de letalidade. Vacinas contra os sorotipos A, C, W-135, e Y estão disponíveis, entretanto, vacinas contra o sorotipo B são esperadas.

Patterns of meningococcal infection in Sudan with emergence of Neisseria meningitidis serogroup W135

This study was conducted during the 2004-2006 epidemic of meningitis in Sudan to follow-up the frequency of disease outbreak or endemic waves and to evaluate the new quadrivalent vaccine for actual application. Samples were collected from Darfur, El Gedaref, Kassala and Khartoum States and transported to the National Health Central Laboratory in Khartoum. Of 196 patients with clinical symptoms and signs of meningitis, conventional culture identified Neisseria meningitidis in 37 [18.9%], confirmed by polymerase chain reaction. N. meningitidis type A was identified in 29 [78.4%] patients, type C in 3 [8.1%] and N. meningitidis W135 in 5 [15.5%]. The serotyping and molecular diagnosis patterns of N. meningitidis showed the emergence of the new strain,W 135, in patients from the borders of Sudan, 3 from the West Darfur, and 1 each from El Gedaref and Kassala. These could be related to the movement of pilgrims through the borders to Saudi Arabia in the Hajj season. Serious consideration may be needed for quadrivalent vaccination to prevent seasonal and Hajj season outbreaks

A importância dos métodos de custeio e valoração nas avaliações econômicas em saúde: repercussões sobre os resultados de avaliação da vacina antimeningocócica C / The importance of costing and valuation methods in economic evaluations in health: impact on the results of evaluation of meningococcal C vaccine

Os objetivos deste artigo são apresentar e comparar os resultados do estudo de custo-efetividade da vacina antimeningocócica C conjugada, no qual inserimos novos dados de custos denominados de "gastos familiares" para tratamento de sequelas, coletados por entrevistas diretas com famílias de pessoas nessa situação, em relação ao modelo de análise apresentado por De Soarez et al, (2011), resultante de um projeto de pesquisa feito para o PNI (Programa Nacional de Imunização) sobre a viabilidade da antimeningocócica C na rotina de vacinação. Mostra-se como resultado que a inserção de novos custos modificou a relação de custo-efetividade da vacina em questão, tornando-a mais efetiva.

This paper aims to present and compare the results of the cost-effectiveness of antimeningococcal C conjugate vaccine, which insert new cost data, collected by personal interviews with families of people with sequels, called "family expenditures" for treatment of sequelae, compared to the analytical model presented by De Soarez et al. (2011), resulting from a research project done for the NIP (National immunization Program) on the feasibility of meningococcal C vaccine in routine vaccination. It is shown that as a result of the inclusion of new costs have changed the cost-effectiveness of the vaccine in question, making the vaccine more cost effective.

Análise crítica das recomendações do uso das vacinas meningocócicas conjugadas / A critical appraisal of the recommendations for the use of meningococcal conjugate vaccines

OBJETIVOS: Analisar a epidemiologia da doença meningocócica no Brasil e o impacto que as recentes evidências acumuladas com a incorporação das vacinas meningocócicas C conjugadas nos programas de imunização podem ter nas diferentes estratégias de uso dessas vacinas. FONTES DOS DADOS: Revisão nas bases de dados MEDLINE, SciELO e LILACS no período de 2000 a 2011. SÍNTESE DOS DADOS: No Brasil, a doença meningocócica é endêmica, com ocorrência periódica de surtos. Os maiores coeficientes de incidência ocorrem em lactentes, sendo o sorogrupo C responsável pela maioria dos casos, motivando a introdução da vacina meningocócica C conjugada no Programa Nacional de Imunizações, em 2010, para crianças menores de 2 anos. A introdução das vacinas meningocócicas C conjugadas nos programas de imunização na Europa, Canadá e Austrália mostrou-se efetiva, com dramática redução na incidência de doença causada pelo sorogrupo C, não apenas nos vacinados, mas também em não vacinados. A efetividade em longo prazo dessas vacinas mostrou-se dependente de uma combinação de persistência de anticorpos, memória imunológica e proteção indireta. Recentes evidências indicando que a persistência de anticorpos não é duradoura em crianças pequenas imunizadas e que a memória imunológica não é rápida o suficiente para protegê-las contra a doença enfatizam a importância da proteção indireta para manutenção da população protegida. CONCLUSÕES: A rápida queda de títulos de anticorpos em crianças vacinadas nos primeiros anos de vida sugere a necessidade de incorporarmos doses de reforço antes da adolescência, especialmente em locais como o Brasil, onde ainda não contamos com o efeito da proteção indireta da população.

OBJECTIVES: To assess the epidemiology of meningococcal disease (MD) in Brazil and the impact that recent evidence and lessons learned from the introduction of meningococcal C conjugate (MCC) vaccines into immunization programs may have on different strategies of vaccine use. SOURCES: Non-systematic review of the MEDLINE, SciELO and LILACS databases covering the period from 2000 to 2011. SUMMARY OF THE FINDINGS: Meningococcal disease is endemic in Brazil, with periodic occurrence of outbreaks. Most cases are associated with serogroup C and the highest incidence rates are observed in infants, encouraging the introduction of MCC vaccine in the National Immunization Program in 2010 for children under 2 years old. The introduction of MCC vaccines into immunization programs in Europe, Canada and Australia proved to be effective, with dramatic reduction in the incidence of serogroup C meningococcal disease, not only in the vaccinated, but also in the unvaccinated individuals. Long-term effectiveness of MCC vaccines was dependent on a combination of antibody persistence, immunologic memory and herd protection. Recent evidence indicating that antibody persistence is not long-lasting in young immunized children, and that immunologic memory is not fast enough to protect them against the disease, emphasize the importance of herd protection to maintain the population protected. CONCLUSIONS: The rapid decline of antibody titers in children vaccinated in the first years of life suggests the need to incorporate booster doses before adolescence, especially in locations like Brazil, where the immunization program did not incorporate catch-up campaigns including adolescents, lacking the herd immunity effect.

Introduction of Nm A conjugate vaccine in Sudan

Sudan, with support from GAVI Alliance and technical cooperation from WHO is planning to introduce Neisseria meningitides [Nm] A conjugate vaccine in in 2012. Over 24.78 million people between the 1-29 year age group living in some of the high risk states of the country will be vaccinated in two phases. In 2012, during the first phase, some of the most high risk states will be covered. The remaining states which are prone to repeated outbreak from meningococcal meningitis will be covered in second phase starting in 2013

Meningococcal disease in Sudan: Sporadic cases so far in the season

During the current high risk season in Sudan, a total of 143 suspected cases of meningococcal disease including 7 deaths [CFR:4.8%] were reported from Sudan. The predominant pathogen was found to be Neisseria meningitides [Nm] serogroup A. Except for one district in North Kordofan state, no other districts in the country have reached either the alert or epidemic threshold

No major outbreak from meningococcal disease

The 2007-2008 epidemic season for meningococcal disease [MCD] is passing off in Sudan without any major outbreak being reported from the country either from its northern part or from southern Sudan. The epidemic season for MCDs, normally, starts in November and stretches as long as the rainy season begins in June-July in the country. Suspected cases of meningococcal diseases [MCD], though, occurred sporadically through out the current epidemic season in Sudan, no major outbreak was recorded. Between 01 January to 15 June 2008 only 2,94 suspected cases of MCDs including 12 deaths [CFR: 4%] were reported by the Federal Ministry of Health [FMOH] of Sudan. However, localized outbreaks from MCDs were detected in one of the sectors [district] of North Kordofan state as well as in Nertiti IDP camp of West Darfur prompting for mass vaccination campaign in these two areas. The causative strain for these two localized outbreaks were N. meningitides serogroup-A. About 20,000 IDPs were vaccinated in Nertiti IDP camp while 60,407 people in the high risk age group [2-30 yrs] in Abuzabed district were vaccinated to contain these two localized outbreaks

Doença meningocócica: aspectos epidemiológicos, fatores de risco e prevenção / Meningococcal disease: epidemiological aspects, risk factors and prevention

A doença meningocócica é uma infecção bacteriana aguda, causada pela Neisseria meningitidis. Apresenta-se sob diversas formas clínicas que vão desde a assintomática até a meningo­coccemia. Existem 13 sorogrupos identificados do microorga­nismo, porém os que mais causam a doença são os A, B, C, Y e W 135. No Brasil, o sorogrupo B predomina desde 1988. A doença ocorre em todo o mundo, sendo um problema de saúde pública, especialmente em algumas regiões, como na área hiperendêmica da África. Acomete, principalmente, crian­ças e adultos jovens e é transmitida por meio das secreções respiratórias de portadores, favorecendo maior contaminação nos contactantes íntimos. Pelo seu caráter epidêmico e alta letalidade, causa pânico na população e impõe a notificação imediata do paciente para que as medidas de controle sejam desencadeadas. O conheci­mento do comportamento epidemiológico da doença meningocócica subsidia estas medidas de controle: quimioprofilaxia e vacinação. O surgimento de vacinas antimeningocócicas conjugadas oferece a perspectiva de um controle efetivo da doença e moti­va esta revisão sobre o tema...

Vacinas meningocócicas conjugadas: eficácia e novas combinações / Meningococcal conjugate vaccines: efficacy and new combinations

OBJETIVO: A doença meningocócica é, ainda hoje, um sério problema de saúde pública, estando associada a elevadas taxas de morbidade e letalidade no mundo e, em especial, no Brasil. Além de discutir as recentes mudanças na epidemiologia da doença meningocócica no mundo, analisamos o desenvolvimento e o impacto das novas vacinas conjugadas na prevenção da doença meningocócica, com ênfase nas diferentes estratégias de imunização utilizadas com essas vacinas. FONTE DOS DADOS: Foram pesquisadas as bases de dados MEDLINE no período de 1996 a 2006, com destaque para artigos de revisão, ensaios clínicos e epidemiológicos. Também foi realizada busca de informações nos portais do Centro de Controle de Doenças, Ministério da Saúde do Brasil e Centro de Vigilância Epidemiológica do Estado de São Paulo. SíNTESE DOS DADOS: Cinco sorogrupos (A, B, C, W135 e Y) respondem por virtualmente todos os casos da doença no mundo, com marcantes diferenças regionais e temporais. As novas vacinas conjugadas contra o meningococo C apresentam inequívocas vantagens em relação às vacinas polissacarídicas. Induzem uma resposta de anticorpos mais eficiente e duradoura, propiciando memória imunológica e redução da incidência de portadores. Os resultados imediatos da introdução dessas vacinas nos programas de imunização foram animadores, com dramática redução da incidência de doença, inclusive em não-vacinados (imunidade de rebanho). Entretanto, recentemente constatou-se perda da eficácia após alguns anos da aplicação da vacina, especialmente entre os lactentes vacinados. CONCLUSÕES:A perda de efetividade das vacinas conjugadas contra o meningococo C, observada após alguns anos da imunização de lactentes jovens, justifica a mudança dos esquemas de vacinação, com a incorporação de uma dose de reforço entre 12 e 18 meses de idade para garantir uma proteção mais duradoura. O recente licenciamento da vacina quadrivalente meningocócica conjugada representa, enfim, a real possibilidade de uma proteção mais abrangente contra a doença meningocócica, restando ainda a necessidade de se desenvolver uma vacina eficaz contra o meningococo B.

Enfermedad por meningococo, Neisseria meningitidis: perspectiva epidemiológica, clínica y preventiva / Meningococcal disease caused by Neisseria meningitidis: epidemiological, clinical, and preventive perspectives

La meningitis bacteriana continúa siendo uno de los grandes problemas de la salud pública mundial. En particular, la infección por Neisseria meningitidis afecta tanto a países desarrollados como subdesarrollados, y se presenta en formas endémicas y epidémicas. La enfermedad meningocóccica se puede manifestar clínicamente no sólo como meningitis, sino con cuadros fulminantes de meningococcemia. La persistencia de N. meningitidis se debe al gran porcentaje de portadores y a la dinámica de transmisión de la bacteria. Aproximadamente 500 millones de personas en el mundo son portadoras de N. meningitidis en la nasofaringe. Los factores de transmisiblidad identificados han sido el tabaquismo activo o pasivo, la presencia de infecciones virales del tracto respiratorio superior, épocas de sequía, y el hacinamiento. Por lo anterior, se han descrito brotes de enfermedad meningocóccica en cuarteles militares, escuelas, cárceles y dormitorios. Algunos determinantes que permiten la invasión sistémica incluyen daños en la mucosa nasofaríngea de portadores, cepas virulentas con formación de cápsula, ausencia de anticuerpos bactericidas y deficiencias del sistema del complemento. El control de la enfermedad meningocóccica en circunstancias endémicas y epidémicas se logra por el tratamiento de casos con antibióticos adecuados (penicilina, ceftriaxona o cloranfenicol), la quimioprofilaxis de contactos cercanos (ciprofloxacina, rifampicina o ceftriaxona), y la vigilancia clínica de éstos. Sin embargo, es fundamental subrayar que la clave para el control efectivo de la enfermedad meningocóccica es la inmunoprofilaxis. Las vacunas disponibles incluyen las de polisacáridos monovalentes o bivalentes (serogrupos A y C), tetravalentes (A, C, Y, W-135), la conjugada (C) o la combinada de proteínas de membrana celular y polisacárido (B y C). Recientemente nos hemos visto forzados a establecer planes nacionales de respuesta que incluyen la disponibilidad de vacuna y de medicamentos para quimioprofilaxis, debido a que se ha documentado un incremento de casos de enfermedad por N. meningitidis, serogrupo C, en el país. Es por lo anterior que esta revisión está dirigida a proporcionar al personal de salud un recordatorio de los aspectos relevantes de la epidemiología, y de los clínicos y preventivos de la enfermedad meningocóccica.

Evaluation of serogroup A meningococcal vaccines in Africa: a demonstration project.

Endemic and epidemic meningococcal disease constitutes a major public-health problem in African countries of the 'meningitis belt' where incidence rates of the disease are many-fold higher (up to 25 cases per 100,000 population) than those in industrialized countries, and epidemics of meningococcal disease occur with rates as high as 1,000 cases per 100,000 people. Using the precedent established during the licensing of conjugate vaccines against Haemophilus influenzae type b and serogroup C meningococci and components of currently-licensed meningococcal polysaccharide vaccines, new meningococcal conjugate vaccines will likely be licensed using immunological endpoints as surrogates for clinical protection. Post-licensure evaluation of vaccine effectiveness will, therefore, be of increased importance. One vaccine being developed is the serogroup A meningococcal (Men A) conjugate vaccine produced by the Meningitis Vaccine Project (MVP), a partnership between the World Health Organization and the Program for Applied Technology in Health. This vaccine will likely be the first meningococcal conjugate vaccine introduced on a large scale in Africa. This paper summarizes the general steps required for vaccine development, reviews the use of immunogenicity criteria as a licensing strategy for new meningococcal vaccines, and discusses plans for evaluating the impact of a meningococcal A conjugate vaccine in Africa. Impact of this vaccine will be measured during a vaccine-demonstration project that will primarily measure the effectiveness of vaccine. Other studies will include evaluations of safety, vaccine coverage, impact on carriage and herd immunity, and prevention-effectiveness studies.

Controle de surto de meningite meningocócica do sorogrupo C no Município de Corupá, Santa Catarina, Brasil, com ações rápidas e efetivas de vigilância epidemiológica e imunização / Control of a community outbreak of group C meningococcal meningitis in Corupá, Santa Catarina State, Brazil, based on rapid and effective epidemiological surveillance and immunization

No ano de 2001, num período de sete dias, em município de pequeno porte localizado na região norte de Santa Catarina, Brasil, foram registrados oito casos de doença meningocócica entre adolescentes e adultos jovens, correspondendo a uma taxa de ataque de 367,5 casos/100 mil habitantes deste segmento populacional. Exames laboratoriais identificaram o meningococo do sorogrupo C em três dos oito casos, o que permitiu utilizar, de acordo com os critérios estabelecidos pelo Ministério da Saúde do Brasil, a estratégia do bloqueio vacinal anti-C para o controle do agravo naquela população sob risco. A vacinação foi levada a todas as pessoas maiores de dois anos de idade, residentes no município. A ausência de casos da doença meningocócica naquela comunidade nos 12 meses após o bloqueio vacinal sinaliza para a importância da pronta intervenção no controle de surtos pela enfermidade.

Changes in epidemiological pattern of meningococcal disease in Saudi Arabia. Does it constitute a new challenge for prevention and control?

Meningococcal meningitis epidemics, which occurred in the Kingdom of Saudi Arabia [KSA] coincided with Hajj and Umra seasons; the 2 major pilgrims to Muslims. In many countries, the disease showed major changes of its epidemiological determinants, in particular to age and prevailing serogroup. This study was conducted to determine the epidemiological trend of meningococcal meningitis disease in KSA. All confirmed meningococcal meningitis cases reported in KSA during the period from January 1999 to December 2002 were studied retrospectively. Confirmation of cases was based on isolation of the causative organism from cerebrospinal fluid [CSF] or blood culture or detection of antigen in the CSF. Personal, clinical and laboratory results were analyzed using Epi info version 6 software. Categorical data were tested using X2 test. A total of 729 cases were reported, 304 cases [42%] were among people coming from abroad for Hajj or Umra and 425 [58%] were among local population. Nearly half of the later [48%] were reported at the 2 holy areas of Makkah and Madinah, KSA. Thirty-nine% of cases were children aged <2 years and 58% were <5 years of age. Proportion of cases affected with serogroup W135 increased over time [up to 95%] and significantly affected children aged <5 years [p<0.001]. Continuous monitoring of epidemiological determinants is essential to guide vaccination policy