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1.
Rev. patol. trop ; 50(2): 1-7, jun. 2021. ilus
Article in English | LILACS | ID: biblio-1254588

ABSTRACT

The COVID-19 pandemic that began in early 2020 is currently the subject of thousands of articles on the various aspects of its epidemiology. One recurrent theme is the phenomenon of herd immunity or herd effect. In this article, I present a short history of the concept, the arguments around its nomenclature, and the ecologist's view of the herd effect, using the case history of the sleeping sickness control in Africa.


Subject(s)
Humans , Trypanosomiasis, African , Immunity, Herd , Ecology , COVID-19
3.
Repert. med. cir ; 30(suplemento): 73-78, 2021. ilus., tab.
Article in English, Spanish | LILACS, COLNAL | ID: biblio-1361448

ABSTRACT

Introducción: la humanidad enfrenta la mayor campaña de vacunación de la historia. El proceso de inmunización contra el COVID-19 que comenzó a principios de diciembre 2020 en Estados Unidos, Reino Unido, Rusia y China, está en marcha en todo el mundo y se destaca en la mayoría de los países más ricos. Objetivo: calcular el tiempo para alcanzar la inmunidad de rebaño para COVID-19 a nivel mundial, a partir de la información de vacunación de Johns Hopkins University. Metodología: la información sobre vacunación diaria a nivel mundial se obtuvo de Johns Hopkins University. Se tomó el período hasta el 30 de junio 2021. Resultados: se determinó que para el 19 de enero 2022 se logrará obtener la inmunidad de rebaño, para esta fecha se habrán aplicado 11.034.357.235 dosis para inmunizar a la población mundial. Conclusión: se infiere el significativo papel que logran los modelos matemáticos a la hora de representar los procesos de vacunación y de esta manera se trazarán en el futuro vías de investigación en la modelización matemática para lograr la inmunidad de rebaño de cualquier proceso infeccioso.


Introduction: humanity faces the greatest vaccination campaign in history. The immunization process against COVID-19, which started in early December 2020 in the United States, United Kingdom, Russia and China, is underway worldwide and is emphasized in most of the wealthiest countries. Objective: to estimate the time to reach global herd immunity against COVID-19, relying on the vaccination data released by Johns Hopkins University. Methodology: global daily vaccination data was obtained from Johns Hopkins University. The period as to June 30 2021 was reviewed. Results: it was determined that herd immunity will be achieved by January 19 2022. As of this date 11.034.357.235 doses will have been administered to immunize the world ́s population. Conclusion: from this research we infer the significant role that mathematical models play when simulating vaccination processes, thus, future research avenues based on mathematical modeling to achieve herd immunity for any infectious process, will be designed.


Subject(s)
Vaccination , SARS-CoV-2 , Immunity, Herd , World Population , Mathematics
4.
Repert. med. cir ; 30(suplemento): 103-106, 2021. ilus.
Article in English, Spanish | LILACS, COLNAL | ID: biblio-1361587

ABSTRACT

Introducción: el camino equitativo para disponer de vacunas seguras y efectivas es primordial para poner fin a la pandemia de COVID-19, por lo que es confortante que haya tantas vacunas en prueba y en desarrollo. La OMS (Organización Mundial de la Salud) trabaja ardua con sus socios para desarrollar, fabricar y distribuir vacunas seguras y eficaces. Metodología: la presente investigación es un estudio transversal, como fuente de información se obtuvo del plan mundial de vacunación contra el COVID-19 de la página web de nuestro mundo en datos. Resultados: se estableció que al 6 de agosto 2021 los países con mayores proporciones de vacunas con esquemas completos fueron: Emiratos Árabes Unidos (72), Uruguay (66), Chile (65), Baréin (62) e Israel (62). Aquellos con mayor porcentaje de vacunación son: Argentina (39), Brasil (31), Arabia Saudita (29), Corea del Sur (25,5) y Malasia (22). Conclusión: es imperioso continuar aumentado la asignación de dosis contra SARS-COV-2 en los diferentes países del mundo y a su vez que cada uno aumente su capacidad de aplicaciones de dosis de la vacuna y de manera específica en lo relacionado con los esquemas completos, que permitan lograr a corto plazo obtener la inmunidad de rebaño a nivel mundial.


Introduction: the equitable path to safe and effective vaccines is paramount to bring the COVID-19 pandemic to an end. Thus, it is reassuring that so many vaccines are being tested and developed. The WHO (World Health Organization), together with its partners, is working hard to develop, manufacture and distribute safe and effective vaccines. Methodology: the present research is a cross-sectional study. Data was taken from the Our World in Data website, based on the global vaccination plan against COVID-19. Results: it was established that as of August 6 2021, the countries with the highest share of allocated vaccines and fully vaccinated people were: the United Arab Emirates (72), Uruguay (66), Chile (65), Bahrain (62) and Israel (62). Those with the highest percentage of applied vaccination doses were: Argentina (39), Brazil (31), Saudi Arabia (29), South Korea (25.5) and Malasya (22). Conclusion: it is imperative that both the allocation of doses of vaccines against SARS-COV-2 and the vaccine application capacity continue to be increased in all countries of the world, underlining the importance of completing the recommended vaccination protocols, in order to achieve herd immunity worldwide in the short term.


Subject(s)
Humans , Male , Female , Vaccination , SARS-CoV-2 , COVID-19 , Immunity, Herd , Pandemics
5.
S. Afr. med. j ; 111(9): 852-856, 2021.
Article in English | AIM, AIM | ID: biblio-1342825

ABSTRACT

Mutations of SARS-CoV-2 have been associated with increased transmissibility and occasionally reduced sensitivity to neutralising antibody activity induced by past ancestry virus infection or current COVID-19 vaccines. Nevertheless, COVID-19 vaccines have consistently demonstrated high efficacy and effectiveness against COVID-19 severe disease, hospitalisation and death, including disease caused by designated variants of concern. In contrast, COVID-19 vaccines are more heterogeneous in reducing the risk of infection and mild COVID19, and are modestly effective in interrupting virus transmission. Ongoing mutations of SARS-CoV-2 resulting in increased transmissibility and relative evasion of neutralising antibody activity induced by past virus infection or COVID-19 vaccines are likely. The duration of protection induced by COVID-19 vaccines is modelled to be relatively short in protecting against infection and mild COVID-19, but is likely to be 2 - 3 years against severe disease. Current experience from the UK and Israel demonstrates that even with high levels of COVID19 vaccine coverage (>85% of the adult population), resurgences with new variants of concern remain a strong probability. Nevertheless, such resurgences are not mirrored by high rates of hospitalisation and death compared with what was experienced in relatively COVID-19 vaccine-naive populations. Even though COVID-19 vaccines are unlikely to result in a herd immunity state, their ability to protect against severe COVID-19 and death could allow for a return to normalcy once a large enough proportion of the adult population in a country has been vaccinated


Subject(s)
Immunity, Herd , Vaccination Coverage , SARS-CoV-2 , COVID-19
6.
Rev. chil. infectol ; 37(3): 231-236, jun. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1126114

ABSTRACT

Resumen Introducción: Los casos de sarampión están resurgiendo en muchos países del mundo. Hubo un brote de sarampión importado entre noviembre de 2018 y febrero de 2019 en Chile, lo que generó preocupación entre el público y las autoridades sanitarias. Muchos se preocuparon por la tasa de inmunización contra el sarampión de la población, un factor que se relaciona con la capacidad reproductiva del virus (medida de transmisibilidad de un patógeno). Objetivo: Aquí estimamos el número reproductivo efectivo (Re) de este brote de sarampión. Resultados: Aunque la estimación tiene mucha incertidumbre por el bajo número de casos y la ausencia de mezcla homogénea de la población, encontramos que Re fue aproximadamente 1,5. Discusión y Conclusiones: En consecuencia estimamos que aproximadamente 90,3% de la población tiene inmunidad al sarampión, lo que coincide con las estimaciones del Ministerio de Salud. Estos resultados sugieren que la población chilena ha establecido la inmunidad colectiva contra la introducción de casos importados de sarampión, lo que refleja un manejo preventivo adecuado de esta enfermedad.


Abstract Background: Measles cases are reemerging in many countries across the globe. There was an outbreak of imported measles between November 2018 and February 2019 in Chile, raising concern among the public and health authorities. Many were worried about the Chilean measles herd immunity, a factor that relates to the reproductive capacity of the virus (measure of transmissibility of a pathogen). Aim: Here we estimate the effective reproductive number (Re) of this measles outbreak. Results: Although the estimate is highly uncertain due to the low number of cases and the absence of homogeneous mixing of the population, we found Re was approximately 1.5. Discussion and Conclusions: Consequently we estimated about 90,3 % had measles immunity, consistent with administrative estimates from the Ministry of Health. These results suggest the Chilean population has established herd immunity against the introduction of imported measles cases, reflecting adequate preventive management of this disease.


Subject(s)
Humans , Vaccination , Measles , Measles Vaccine , Chile , Disease Outbreaks , Immunity, Herd
7.
Rev. Soc. Bras. Med. Trop ; 53: e20200351, 2020. graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1136900

ABSTRACT

Abstract INTRODUCTION: Estimates of the number of individuals infected by severe acute respiratory syndrome coronavirus 2 are important for health planning and establishment of expectations regarding herd immunity. METHODS: Seven testing rounds of a serological survey were conducted at 1-week intervals between April 19 and May 31, 2020 in Teresina municipality. RESULTS Over the 7 weeks, serological positivity increased from 0.56% (95% confidence interval [CI]: 0.18%-1.30%) to 8.33% (95% CI: 6.61%-10.33%), representing 33-53 persons infected for each reported case. CONCLUSIONS: Serological screening may be an important tool for understanding the immunity of a population and planning community interventions.


Subject(s)
Humans , Pneumonia, Viral/epidemiology , Coronavirus Infections/epidemiology , Betacoronavirus/immunology , Pneumonia, Viral/diagnosis , Pneumonia, Viral/immunology , Brazil/epidemiology , Confidence Intervals , Seroepidemiologic Studies , Sensitivity and Specificity , Coronavirus Infections , Coronavirus Infections/diagnosis , Coronavirus Infections/immunology , Immunity, Herd , False Positive Reactions , Asymptomatic Diseases/epidemiology , Pandemics , Betacoronavirus
8.
Rev. saúde pública (Online) ; 54: 131, 2020. tab, graf
Article in English | SES-SP, LILACS, BBO, SES-SP | ID: biblio-1145072

ABSTRACT

ABSTRACT OBJECTIVE: To estimate the seroprevalence of SARS-CoV-2 in the state of Maranhão, Brazil. METHODS: A population-based household survey was performed, from July 27, 2020 to August 8, 2020. The estimates considered clustering, stratification and non-response. Qualitative detection of IgM and IgG antibodies was performed in a fully-automated Elecsys® Anti-SARS-CoV-2 electrochemiluminescence immunoassay on the Cobas® e601 analyzer (Roche Diagnostics). RESULTS: In total, 3,156 individuals were interviewed. Seroprevalence of total antibodies against SARS-CoV-2 was 40.4% (95%CI 35.6-45.3). Population adherence to non-pharmaceutical interventions was higher at the beginning of the pandemic than in the last month. SARS-CoV-2 infection rates were significantly lower among mask wearers and among those who maintained social and physical distancing in the last month compared to their counterparts. Among the infected, 26.0% were asymptomatic. The infection fatality rate (IFR) was 0.14%, higher for men and older adults. The IFR based on excess deaths was 0.28%. The ratio of estimated infections to reported cases was 22.2. CONCLUSIONS: To the best of our knowledge, the seroprevalence of SARS-CoV-2 estimated in this population-based survey is one of the highest reported. The local herd immunity threshold may have been reached or might be reached soon.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Aged , Young Adult , Seroepidemiologic Studies , Immunity, Herd , COVID-19/immunology , Antibodies, Viral/blood , Brazil/epidemiology , Pandemics , SARS-CoV-2 , Middle Aged
9.
Rev. chil. pediatr ; 90(5): 559-562, oct. 2019.
Article in Spanish | LILACS | ID: biblio-1058184

ABSTRACT

Resumen: A pesar del enorme impacto de las vacunas en la salud de la población, estas han sido y son objeto de cuestionamientos por grupos que las consideran innecesarias o inseguras y argumentan que las personas tienen el derecho a decidir sobre si estas deben ser administradas o no. Sin embargo el uso de vacunas tiene connotaciones distintas a otras decisiones en salud, ya que no vacunar impacta no solo al individuo, sino también a la comunidad que lo rodea. El inmunizar a un alto porcentaje de la población permite limitar la circulación de los agentes infecciosos, logrando la llamada inmunidad comunitaria que protege a los no vacunados por razones médicas o porque son muy pequeños. Por esta razón muchos países han definido las vacunas como obligatorias. Como Comité Consultivo de Inmunizaciones nos parece que esta estrategia es correcta sin embargo debe ser acompañada por una política de educación de la población y personal de salud sobre los beneficios y riesgos reales de las va cunas. Así mismo es necesario introducir mejoras en el sistema de notificación de reacciones adversas a vacunas haciéndolo más accesible. Adicionalmente se debe dar respuesta oportuna a los afectados por supuestas o reales reacciones a vacunas y en los casos de eventos adversos graves efectivamente asociados a vacunas. Entregar cobertura económica y acompañamiento. Finalmente es esencial la coordinación entre los diferentes actores y comunicadores para transmitir mensajes que generen confianza y respondan a las inquietudes de la población de hoy en día.


Abstract: Although vaccines have had a tremendous impact in public health they are questioned by certain groups that consider them unnecessary or unsafe and argue in favor of the right to decide to be vacci nated or not. However vaccines must have special considerations because unlike other medical deci sions, not vaccinating has consequences not only for the individual but also for other members of the community. Immunizing a high proportion of the population limits the circulation of an infectious agent attaining what is called community or herd immunity that protects the susceptible members of the group. For this reason many countries consider vaccination mandatory as a responsibility of every citizen. This committee agrees with this view but thinks other strategies should be implemented as well, such as special educational efforts for the public and parents addressing benefits and real risks of vaccinating. Also health care professionals should be trained in vaccines. The notification system for adverse events currently available should be improved and be more accessible. Persons truly affected by adverse events due to vaccination should receive on time responses and be offered psychological and financial support. Finally all stakeholders should make coordinated efforts to work together to deliver messages that answer concerns on vaccines and bring confidence back to the public.


Subject(s)
Humans , Vaccines/administration & dosage , Vaccination/statistics & numerical data , Vaccination Refusal/psychology , Health Policy , Parents/psychology , Chile , Public Health , Health Education/methods , Vaccination/legislation & jurisprudence , Health Personnel/organization & administration , Immunity, Herd , Vaccination Refusal/legislation & jurisprudence
10.
Article in English | WPRIM | ID: wpr-765073

ABSTRACT

Until 1995, the incidence of symptomatic acute hepatitis A was minimal and there were no cases of national outbreak in Korea. However, there was a nationwide outbreak of hepatitis A that peaked in 2009. In 2019, a total of 10,083 cases of acute hepatitis A were reported for seven months of the year according to the Korea Center for Disease Control and Prevention. This may be attributed to the proportion of susceptible subjects in the Korean population, as about 10 years have passed since herd immunity was induced by the epidemic occurring during the late 2000s. Recent studies have shown that the rate of seropositivity for anti-hepatitis A virus antibodies (anti-HAV) is the lowest in adults in their 20s and has not changed much over the past 10 years, and seropositivity of anti-HAV in adults in their 30s has continued to decline from 69.6% in 2005 to 32.4% in 2014. Most young adults who have not yet experienced hepatitis A and are not vaccinated are vulnerable to hepatitis A infection. This year's epidemic of hepatitis A is a predictable outcome for vulnerable populations. Therefore, effective acute hepatitis A control and prevention strategies are needed, particularly for those in their 20s and 30s.


Subject(s)
Adult , Antibodies , Hepatitis A Antibodies , Hepatitis A , Hepatitis , Humans , Immunity, Herd , Incidence , Korea , Prevalence , Vulnerable Populations , Young Adult
11.
Article in English | WPRIM | ID: wpr-763370

ABSTRACT

PURPOSE: Neisseria meningitidis and Neisseria gonorrhoeae share between 80% and 90% of their genetic sequence. Meningococcal serogroup B vaccines based on outer membrane vesicles—such as VA-MENGOC-BC—could cross-protect against gonorrhea. The aim of this study was to analyze the incidence rates of gonorrhea and other sexually transmitted diseases with respect to the use of the VA-MENGOC-BC vaccine. MATERIALS AND METHODS: Health statistics between 1970 and 2017 were reviewed and the incidence of meningococcal disease and sexually transmitted diseases (gonorrhea, syphilis, condyloma acuminatum, hepatitis B and human immunodeficiency virus infection) were analyzed during the pre- and post-vaccination periods. Gonorrhea incidence was also analyzed by age groups. RESULTS: VA-MENGOC-BC was successfully used to control a meningococcal epidemic in Cuba. The strategy to combat the epidemic was carried out in two stages. The first one was a nationwide mass-vaccination campaign from 1989 to 1990, targeting the population at highest-risk aged 3 months to 24 years. During the second stage, begun in 1991, it was included in the Expanded Immunization Program. Gonorrhea incidence increased from 1970 to 1989. However, after the VA-MENGOC-BC massive vaccination campaign a sharp decrease of gonorrhea incidence was observed. It lasted between 1989 and 1993. A second incidence peak was detected in 1995, but it dropped again. Data clearly show a decline in the incidence of gonorrhea following massive vaccination, in contrast with other sexually transmitted diseases. Incidence rates in unvaccinated age groups also decreased, probably due to herd immunity. CONCLUSION: There is evidence that VA-MENGOC-BC could induce a moderate protection against gonorrhea.


Subject(s)
Cuba , Gonorrhea , Hepatitis B , HIV , Humans , Immunity, Herd , Immunization Programs , Incidence , Membranes , Neisseria gonorrhoeae , Neisseria meningitidis , Serogroup , Sexually Transmitted Diseases , Syphilis , Vaccination , Vaccines
12.
Article in English | WPRIM | ID: wpr-741503

ABSTRACT

Outbreaks of porcine reproductive and respiratory syndrome virus (PRRSV) in vaccinated sow herds from occurrence to stabilization were monitored and analyzed in terms of serology and reproductive performance. Three different conventional pig farms experienced severe reproductive failures with the introduction of a type 1 PRRSV. These farms had adopted mass vaccination of sows using a type 2 PRRSV modified live vaccine (MLV). Therefore, to control the type 1 PRRSV, an alternative vaccination program utilizing both type 1 and type 2 MLV was undertaken. Following whole herd vaccinations with both types of MLV, successful stabilization of PRRS outbreaks was identified based on serological data (no viremia and downward trends in ELISA antibody titers in both sows and suckling piglets) and recovery of reproductive performance. Additionally, through comparison of the reproductive parameters between outbreak and non-outbreak periods, it was identified that PRRSV significantly affected the farrowing rate and the number of suckling piglets per litter at all three pig farms. Comparison of reproductive parameters between periods when the different vaccination strategies were applied revealed that the number of piglets born in total and born dead per litter were significantly increased after the introduction of the type 1 PRRS MLV.


Subject(s)
Agriculture , Disease Outbreaks , Enzyme-Linked Immunosorbent Assay , Immunity, Herd , Immunity, Heterologous , Mass Vaccination , Porcine Reproductive and Respiratory Syndrome , Porcine respiratory and reproductive syndrome virus , Vaccination , Viremia
14.
Rev. AMRIGS ; 60(4): 320-326, out.-dez. 2016. graf
Article in Portuguese | LILACS | ID: biblio-847725

ABSTRACT

Introdução: A Doença Meningocócica (DM) é uma infecção bacteriana aguda causada pela Neisseria meningitidis. Acomete principalmente crianças menores de cinco anos, sobretudo as menores de um ano. Suas manifestações clínicas variam desde doença leve até síndrome séptica e/ou meningite. Diante da letalidade da doença, o Ministério da Saúde incluiu no calendário vacinal, no segundo semestre de 2010, a vacina adsorvida meningocócica C (conjugada). Justificativa: Considerando a recente implementação da vacina no serviço público, é necessário avaliar o impacto desta na saúde da população. Este estudo tem como objetivo descrever a ocorrência de Meningite Meningocócica do tipo C em crianças menores de cinco anos na macrorregional Sul do Estado de Santa Catarina dois anos antes (2008 e 2009) e dois anos depois (2011-2012) após a campanha vacinal contra o meningococo C, realizada no ano de 2010. Métodos: Este é um estudo observacional do tipo transversal. Resultados/Discussão: No período estudado, houve apenas cinco casos confirmados de doença meningocócica. O baixo número de casos deve-se provavelmente à ampla utilização da vacina em clínicas particulares já em anos anteriores aos estudados. Nenhuma criança morreu devido à meningite meningocócica ou meningococcemia, sendo que estudos no Brasil em períodos anteriores à vacinação mostraram letalidade em torno de 20%. Conclusão: O menor número de casos e menor mortalidade pela DM demonstram maior efetividade da Vigilância Epidemiológica e efetividade do diagnóstico precoce (AU)


Introduction: Meningococcal disease (MD) is an acute bacterial infection caused by Neisseria meningitidis. It mainly affects children under five years of age, especially children under one year. Its clinical manifestations range from mild disease to septic syndrome and/or meningitis. Given the lethality of the disease, the Ministry of Health included the adsorbed meningococcal C vaccine (conjugated) in the vaccine calendar in the second half of 2010. Justification: Considering the recent implementation of the vaccine in the public service, it is necessary to evaluate its impact on the health of the population. This study aims to describe the occurrence of Meningococcal Meningitis type C in children under five years of age in the southern macro-region of the State of Santa Catarina two years before (2008-2009) and two years after (2011-2012) the vaccination campaign against meningococcus C carried out in 2010. Methods: This is an observational cross-sectional study. Results/Discussion: In the study period, there were only five confirmed cases of meningococcal disease. The low number of cases is likely due to the wide use of the vaccine in private clinics already years before those studied here. No child died due to meningococcal meningitis, and studies in Brazil prior to vaccination show lethality around 20%. Conclusion: The lower number of cases and lower mortality due to MD demonstrate greater effectiveness of the Epidemiological Surveillance and the effectiveness of early diagnosis (AU)


Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Meningococcal Infections/epidemiology , Meningococcal Infections/prevention & control , Meningococcal Vaccines/immunology , Neisseria meningitidis, Serogroup C/immunology , Brazil/epidemiology , Cross-Sectional Studies , Immunity, Herd , Immunization Programs , Treatment Outcome , Vaccines, Conjugate
15.
Article in English | WPRIM | ID: wpr-30994

ABSTRACT

The epidemiology of human group A rotavirus was analyzed by examining genotypic data acquired from 1989 to 2009 in South Korea. This information was derived from all the available published articles on rotavirus studies in South Korea, retrieved from both the PubMed and KoreaMed databases. Four common G types (G1, G2, G3, and G4) and three common P types (P[8], P[4], and P[6]) accounted for approximately 93% and 99% of the rotavirus reports, respectively. The G9 type was frequently detected after 2000, and because of this prevalence, it is considered to be the fifth most important G type rotavirus after the G1.G4 genotypes. Less common G types of the virus such as G12, G11, and G10 were detected in some geographic settings, and it is important to consider the context of these subtypes and their epidemiological significance. The P[9] virus genotype was observed in the study and has been discussed in many other studies; however, the P[3], P[10] and P[25] genotypes were rarely detected in the epidemiological research. In general, the distributions of the G and P genotypes showed temporal and geographical fluctuations, and a nationwide rotavirus vaccine program that targeted these genotypes demonstrated effectiveness in protecting against the circulating rotavirus strains. However, further analysis is needed to determine the true long-term effectiveness of these vaccines; the analysis should also consider the unexpected effects of vaccinations, such as vaccine-induced diseases, herd immunity, and changes in host susceptibilities.


Subject(s)
Epidemiology , Genotype , Humans , Immunity, Herd , Prevalence , Republic of Korea , Rotavirus , Vaccination , Vaccines , Viruses
17.
J. pediatr. (Rio J.) ; 88(3): 195-202, maio-jun. 2012. ilus, tab
Article in Portuguese | LILACS | ID: lil-640772

ABSTRACT

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.


Subject(s)
Humans , Immunization Programs/statistics & numerical data , Meningitis, Meningococcal/epidemiology , Meningitis, Meningococcal/prevention & control , Meningococcal Vaccines/therapeutic use , Neisseria meningitidis, Serogroup C/immunology , Australia , Brazil/epidemiology , Europe , Immunity, Herd , Incidence , North America , Vaccines, Conjugate/therapeutic use
18.
Article in Korean | WPRIM | ID: wpr-186388

ABSTRACT

Pertussis is a pediatric infectious disease with one of the highest degrees of infectivity. Although pertussis may cause asymptomatic infections in children and adults with immunity, it can cause life-threatening diseases in newborn babies or infants. We report three cases of pertussis in infants <3 months of age without DTaP immunization who have received symptomatic treatment with the diagnosis of bronchiolitis from other hospitals, and subsequently correctly diagnosed and treated. The patients did not have the characteristic whooping cough, but the main symptoms were episodic cough, intermittent vomiting, and cyanosis. Based on culture results for Bordetella pertussis and PCR, pertussis was diagnosed and treated without any complications. As it is assumed that adults, adolescents, and asymptomatic patients may serve as sources of infection, immunization with Tdap vaccine is recommended to prevent dissemination of pertussis from adolescents and adults to infants, and thus maintain herd immunity.


Subject(s)
Adolescent , Adult , Asymptomatic Infections , Bordetella pertussis , Bronchiolitis , Child , Communicable Diseases , Cough , Cyanosis , Humans , Immunity, Herd , Immunization , Infant , Infant, Newborn , Polymerase Chain Reaction , Vomiting , Whooping Cough
19.
Article in English | WPRIM | ID: wpr-234100

ABSTRACT

<p><b>INTRODUCTION</b>We undertook a study to evaluate the effectiveness of the National Childhood Immunisation Programme (NCIP) over the past 26 years by reviewing the epidemiological trends of the diseases protected, the immunisation coverage and the changing herd immunity of the population during the period of 1982 to 2007.</p><p><b>MATERIALS AND METHODS</b>The epidemiological data of all cases of diphtheria, pertussis, poliomyelitis, measles, mumps, rubella and acute hepatitis B notified to the Communicable Diseases Division, Ministry of Health (MOH) from 1982 to 2007 were collated and analysed. Data on tuberculosis (TB) cases were obtained from the TB Control Unit, Tan Tock Seng Hospital. Cases of neonatal tetanus and congenital rubella syndrome (CRS) among infants born in Singapore were identified from the Central Claims Processing System. The number of therapeutic abortions performed for rubella infections was retrieved from the national abortion registry. Coverage of the childhood immunisation programme was based on the immunisation data maintained by the National Immunisation Registry, Health Promotion Board. To assess the herd immunity of the population against the various vaccine-preventable diseases protected, the findings of several serological surveys conducted from 1982 to 2005 were reviewed.</p><p><b>RESULTS</b>The incidence of vaccine-preventable diseases covered under the NCIP had declined over the last 26 years with diphtheria, neonatal tetanus, poliomyelitis and congenital rubella virtually eliminated. The last case of childhood TB meningitis and the last case of acute hepatitis B in children below 15 years were reported in 2002 and 1996, respectively.</p><p><b>CONCLUSION</b>The NCIP has been successfully implemented as evidenced by the disappearance of most childhood diseases, excellent immunisation coverage rate in infants, preschool and school children, and high level of herd immunity of the childhood population protected.</p>


Subject(s)
Adolescent , Adult , Child , Child, Preschool , Communicable Disease Control , Communicable Diseases , Epidemiology , Disease Notification , Humans , Immunity, Herd , Immunization Programs , Incidence , Infant , Population Surveillance , Prevalence , Singapore , Epidemiology
20.
Epidemiology and Health ; : e2009003-2009.
Article in English | WPRIM | ID: wpr-721083

ABSTRACT

OBJECTIVES: The incidence of clinical hepatitis A has increased in young Korean adults since the mid-1990s. Although hepatitis A vaccinations have been administered in private clinics over the past 10 yr, no data exist on the vaccination rate and relating factors. METHODS: In 2005, a population-based survey of 12-35-month-old children was carried out in Nonsan, Korea. An interview survey was completed for 71.3% of the children. All data came from a vaccination card or confirmation from a provider. RESULTS: The hepatitis A vaccination rate was 42.3% for > or =1 dose and 24.7% for 2-dose. The results of the multivariate regression analysis for the hepatitis A vaccination showed that the second (OR=1.6) and third and successive children (OR=3.3) were less often immunized than the first child. Low economic status (OR=1.6), rural area (OR=1.5) and employed mother (OR=1.5) were also correlated with a lower vaccination rate. The hepatitis A vaccination rate was significantly lower in children who had no other vaccinations: measlesmumps-rubella (OR=2.8 for > or =1 dose and 7.3 for 2-dose), varicella (OR=20.2 and 22.0, respectively) and Haemophilus influenza type b (OR=14.3 and 13.3, respectively). CONCLUSION: To prevent outbreaks of clinical hepatitis A by enough herd immunity, a vaccination should be included in the National Immunization Program and a vaccination policy developed and implemented that can overcome the barriers to immunization such as late birth order and a mother's employment.


Subject(s)
Adult , Birth Order , Chickenpox , Child , Disease Outbreaks , Employment , Haemophilus , Hepatitis , Hepatitis A , Humans , Immunity, Herd , Immunization , Immunization Programs , Incidence , Infant , Influenza, Human , Korea , Mothers , Porphyrins , Risk Factors , Vaccination
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