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Pan Afr Med J ; 39: 41, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34422164


Introduction: regular in-service training of healthcare workers within the immunization program is critical to address the program needs created by the introduction of new vaccines and technologies, as well as the expanding scope of immunisation programmes beyond infant immunization and towards a life-course approach. National immunization programs conduct in-service training of health workers depending on program needs and particularly when new program elements are introduced. Methods: we conducted a survey of national and provincial level immunization program staff in 9 countries in the World Health Organization (WHO) African Region to determine the perceived needs and preferred training methods for capacity building in immunisation. Results: nearly all of the respondents (98.3%) stated that there are skill gaps at their respective levels in the immunization program which require training, with 88% indicating that mid-level program management (MLM) training was needed to train new program staff, while 78% indicated program performance gaps and 60% of the respondents stated that refresher training is needed. Program areas identified as top priorities for training included immunisation monitoring and data quality, sustainable immunization financing, adverse events monitoring and community mobilization. More than three quarters of the respondents (78%) think that online MLM training is adequate to address program gaps. Only four of the 9 immunization program managers indicated that they regularly monitor the number of MLM trained staff within their national program. Conclusion: there is a strong need for in-service training of immunization program officers in the countries surveyed, especially at the subnational levels. Program managers should conduct regular monitoring of the training status of staff, as well as conduct detailed training needs assessments in order to tailor the training approaches and topics. Online training provides an acceptable approach for capacity building of immunization program staff.

Pessoal de Saúde/educação , Programas de Imunização/organização & administração , Capacitação em Serviço/métodos , África , Fortalecimento Institucional , Competência Clínica , Pessoal de Saúde/normas , Humanos , Imunização/métodos , Imunização/normas , Inquéritos e Questionários , Vacinas/administração & dosagem
Clin Infect Dis ; 2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34089588


BACKGROUND: Rotavirus is the leading cause of acute gastroenteritis (AGE) among children worldwide. Prior to rotavirus vaccine introduction, over one third of AGE hospitalizations in Africa were due to rotavirus. We describe the impact of rotavirus vaccines using data from the African Rotavirus Surveillance Network (ARSN). METHODS: For descriptive analysis, we included all sites reporting to ARSN for any length of time between 2008-2018. For vaccine impact analysis, continuous surveillance throughout the year was required to minimize potential bias due to enrollment of partial seasons and sites had to report a minimum of 100 AGE cases per year. We report the proportion of rotavirus AGE cases by year relative to vaccine introduction, and the relative reduction in the proportion of rotavirus AGE cases reported following vaccine introduction. RESULTS: From 2008-2018, 97,366 prospectively enrolled hospitalized children <5 years of age met the case definition for AGE, and 34.1% tested positive for rotavirus. Among countries that had introduced rotavirus vaccine, the proportion of hospitalized AGE cases positive for rotavirus declined from 39.2% in the pre-vaccine period to 25.3% in the post-vaccine period, a 35.5% (95% CI: 33.7-37.3) decline. No declines were observed among countries that had not introduced the vaccine over the 11-year period. CONCLUSION: Rotavirus vaccine introduction led to large and consistent declines in the proportion of hospitalized AGE cases that are positive for rotavirus. To maximize the public health benefit of these vaccines, efforts to introduce rotavirus vaccines to the remaining countries in the region and improve coverage should continue.

Vaccine ; 39(23): 3111-3119, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-33958225


The World Health Organization (WHO) recommended the worldwide use of rotavirus vaccines initially in 2007 and 2009 applying a strict age restriction criterion due to the potential for age-related association with increased risk of intussusception in infants. The restriction was relaxed in the 2013 after detailed review of robust safety data generated in post-marketing surveillance studies. We assessed the status of the implementation of the 2013 recommendation to remove age restriction in the WHO African region (AFR). Of the approximately 75% (35/47) of countries that had introduced the vaccine by 2018, only 43% (15/35) removed age restriction, exclusively from South and East sub-region (78%, 14/18). Avoiding confusion at the health facilities and financial constraints particularly resources required for re-training the health workers, use of vaccine off-label were cited as the main reasons for not implementing the 2013 WHO recommendation on age restriction removal. The 2013 WHO recommendation has not been fully implemented by African countries, suggesting the need for technical advisory bodies to further guide the countries, continue monitoring the implementation status and impact on the rotavirus vaccine coverage and intussusception in the Africa region.

Intussuscepção , Infecções por Rotavirus , Vacinas contra Rotavirus , África , Humanos , Lactente , Intussuscepção/induzido quimicamente , Intussuscepção/epidemiologia , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/prevenção & controle , Organização Mundial da Saúde
N Engl J Med ; 381(5): 444-454, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29443626


BACKGROUND: In 2016, the response to a yellow fever outbreak in Angola and the Democratic Republic of Congo led to a global shortage of yellow fever vaccine. As a result, a fractional dose of the 17DD yellow fever vaccine (containing one fifth [0.1 ml] of the standard dose) was offered to 7.6 million children 2 years of age or older and nonpregnant adults in a preemptive campaign in Kinshasa. The goal of this study was to assess the immune response to the fractional dose in a large-scale campaign. METHODS: We recruited participants in four age strata at six vaccination sites. We assessed neutralizing antibody titers against yellow fever virus in blood samples obtained before vaccination and at 1 month and 1 year after vaccination, using a plaque reduction neutralization test with a 50% cutoff (PRNT50). Participants with a PRNT50 titer of 10 or higher were considered to be seropositive. Those with a baseline titer of less than 10 who became seropositive at follow-up were classified as having undergone seroconversion. Participants who were seropositive at baseline and who had an increase in the titer by a factor of 4 or more at follow-up were classified as having an immune response. RESULTS: Among 716 participants who completed the 1-month follow-up, 705 (98%; 95% confidence interval [CI], 97 to 99) were seropositive after vaccination. Among 493 participants who were seronegative at baseline, 482 (98%; 95% CI, 96 to 99) underwent seroconversion. Among 223 participants who were seropositive at baseline, 148 (66%; 95% CI, 60 to 72) had an immune response. Lower baseline titers were associated with a higher probability of having an immune response (P<0.001). Among 684 participants who completed the 1-year follow-up, 666 (97%; 95% CI, 96 to 98) were seropositive for yellow fever antibody. The distribution of titers among the participants who were seronegative for yellow fever antibody at baseline varied significantly among age groups at 1 month and at 1 year (P<0.001 for both comparisons). CONCLUSIONS: A fractional dose of the 17DD yellow fever vaccine was effective at inducing seroconversion in participants who were seronegative at baseline. Titers remained above the threshold for seropositivity at 1 year after vaccination in nearly all participants who were seropositive at 1 month after vaccination. These findings support the use of fractional-dose vaccination for outbreak control. (Funded by the U.S. Agency for International Development and the Centers for Disease Control and Prevention.).

Vacina contra Febre Amarela/imunologia , Febre Amarela/prevenção & controle , Vírus da Febre Amarela/imunologia , Adolescente , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , República Democrática do Congo/epidemiologia , Surtos de Doenças , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Soroconversão , Febre Amarela/epidemiologia , Febre Amarela/imunologia , Vacina contra Febre Amarela/administração & dosagem , Vírus da Febre Amarela/isolamento & purificação , Adulto Jovem
Am J Trop Med Hyg ; 97(4_Suppl): 28-36, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29064356


Following the 2010 earthquake, Haiti was at heightened risk for vaccine-preventable diseases (VPDs) outbreaks due to the exacerbation of long-standing gaps in the vaccination program and subsequent risk of VPD importation from other countries. Therefore, partners supported the Haitian Ministry of Health and Population to improve vaccination services and VPD surveillance. During 2010-2016, three polio, measles, and rubella vaccination campaigns were implemented, achieving a coverage > 90% among children and maintaining Haiti free of those VPDs. Furthermore, Haiti is on course to eliminate maternal and neonatal tetanus, with 70% of communes achieving tetanus vaccine two-dose coverage > 80% among women of childbearing age. In addition, the vaccine cold chain storage capacity increased by 91% at the central level and 285% at the department level, enabling the introduction of three new vaccines (pentavalent, rotavirus, and pneumococcal conjugate vaccines) that could prevent an estimated 5,227 deaths annually. Haiti moved from the fourth worst performing country in the Americas in 2012 to the sixth best performing country in 2015 for adequate investigation of suspected measles/rubella cases. Sentinel surveillance sites for rotavirus diarrhea and meningococcal meningitis were established to estimate baseline rates of those diseases prior to vaccine introduction and to evaluate the impact of vaccination in the future. In conclusion, Haiti significantly improved vaccination services and VPD surveillance. However, high dependence on external funding and competing vaccination program priorities are potential threats to sustaining the improvements achieved thus far. Political commitment and favorable economic and legal environments are needed to maintain these gains.

Monitoramento Epidemiológico , Programas de Imunização/organização & administração , Vigilância de Evento Sentinela , Armazenamento de Medicamentos , Haiti , Humanos , Sarampo/epidemiologia , Sarampo/prevenção & controle , Vacina contra Sarampo/uso terapêutico , Meningite Meningocócica/epidemiologia , Meningite Meningocócica/prevenção & controle , Vacinas Meningocócicas/uso terapêutico , Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/uso terapêutico , Poliomielite/epidemiologia , Poliomielite/prevenção & controle , Vacinas contra Poliovirus/uso terapêutico , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/uso terapêutico , Rubéola (Sarampo Alemão)/epidemiologia , Rubéola (Sarampo Alemão)/prevenção & controle , Vacina contra Rubéola/uso terapêutico , Tétano/epidemiologia , Tétano/prevenção & controle , Toxoide Tetânico/uso terapêutico
Vaccine ; 32(1): 69-73, 2013 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-24188751


BACKGROUND: Haiti had set a national goal to eliminate measles and rubella, as well as congenital rubella syndrome (CRS) by 2010. A 2007-2008 nationwide measles and rubella vaccination campaign targeting 1-19 years, however, reached only 79% of the target population. To assess whether population immunity was adequate to support elimination, we conducted a national serosurvey. METHODS: We systematically selected 740 serum specimens collected from pregnant women in a 2012 national antenatal HIV sentinel serosurvey across four age strata: 15-19, 20-24, 25-29 and 30-39 years. Sera were tested for measles and rubella specific immunoglobulin G antibodies (IgG) using commercial immunoassays. We classified sera as seropositive, seronegative or indeterminate per manufacturer's instructions, and analyzed seroprevalence according to age strata, and rural or urban residence. We assessed immunity by estimating antibody concentrations in international units per milliliter (IU/mL) for seropositive and indeterminate sera. Measles IgG concentrations >0.12 IU/mL and rubella IgG concentrations >10 IU/mL were considered clinically protective. RESULTS: Of 740 sera, 696 (94.1%) were seropositive and 20 (2.7%) were indeterminate for measles IgG; overall 716 (96.8%) sera had IgG concentrations >0.12 IU/mL. For rubella IgG, 691 (93.4%) sera were seropositive and 1 (0.1%) was indeterminate; a total of 687 (92.8%) had IgG concentrations >10 IU/mL. Measles seropositivity varied across age strata (p=0.003); seropositivity increased from 88.6% among 15-19 year olds to 98.4% among 30-39 year olds (Cochran-Armitage trend tes t ≤ 0.0001). Rubella seropositivity did not differ across age strata. There were no statistically significant differences in measles or rubella seropositivity by urban versus rural residence. CONCLUSION: Despite previous low vaccination coverage for measles, results from this serosurvey indicate high levels of measles and rubella seropositivity in pregnant women, and contribute to the evidence for measles, rubella and CRS elimination from Haiti by the target date.

Anticorpos Antivirais/imunologia , Sarampo/epidemiologia , Sarampo/imunologia , Rubéola (Sarampo Alemão)/epidemiologia , Rubéola (Sarampo Alemão)/imunologia , Adolescente , Adulto , Anticorpos Antivirais/sangue , Feminino , Haiti/epidemiologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Vacina contra Sarampo-Caxumba-Rubéola/imunologia , Gravidez , Estudos Soroepidemiológicos , Adulto Jovem