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A maternal vaccine to protect newborns against invasive Streptococcus agalactiae infection is a developing medical need. The vaccine should be offered during the third trimester of pregnancy and induce strong immune responses and placental transfer of protective antibodies. Polysaccharide vaccines against S. agalactiae conjugated to protein carriers are in advanced stages of development. Additionally, protein-based vaccines are also in development, showing great promise as they can provide protection regardless of serotype. Furthermore, safety concerns regarding a new vaccine are the main barriers identified. Here, we present vaccines in development and identified safety, cost, and efficacy concerns, especially in high-need, low-income countries.
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Infecções Estreptocócicas , Vacinas Estreptocócicas , Streptococcus agalactiae , Streptococcus agalactiae/imunologia , Humanos , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/prevenção & controle , Infecções Estreptocócicas/microbiologia , Vacinas Estreptocócicas/imunologia , Gravidez , Feminino , Animais , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/prevenção & controle , Complicações Infecciosas na Gravidez/microbiologia , Desenvolvimento de Vacinas , Recém-Nascido , Anticorpos Antibacterianos/imunologiaRESUMO
INTRODUCTION: Despite a recommendation by PAHO for Tdap vaccination in pregnant women since 2019, uptake remains suboptimal across Latin America. This study evaluated the knowledge and attitudes of women towards maternal Tdap vaccination in Colombia, Peru, and Panama to identify the critical behavioral and social drivers of Tdap vaccine uptake during pregnancy. METHODS: A cross-sectional online survey was undertaken between December 8, 2022, and January 11, 2023, targeting women in Colombia, Peru, or Panama with a child 12 months or under. We collected data on respondents' demographics, social and behavioral determinants of vaccine acceptance, determinants of vaccine uptake (using the validated 5As taxonomy), and previous vaccination experience. RESULTS: In the 938 respondents who completed the survey (Panama, n = 325; Peru, n = 305; Colombia, n = 308), 73-80 % had received the influenza vaccine, whereas only 30-39 % had received a Tdap vaccine. Significant correlates of Tdap vaccine uptake common to all three countries included a health professional recommendation, knowledge of the vaccine and location of vaccination, perceived vulnerability to pertussis infection, perceived importance of immunization, and receipt of a reminder. In specific countries, nonvaccinated women were more likely to cite issues with ease of access (Panama, Colombia), affordability (opportunity costs; Peru, Colombia), and understanding the rationale for vaccination in pregnancy (Panama, Colombia). CONCLUSION: To increase maternal Tdap vaccine uptake, health professionals should be encouraged to recommend vaccination consistently, and pregnant women should receive reminders explaining why and where to be vaccinated.
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Vacinas contra Difteria, Tétano e Coqueluche Acelular , Coqueluche , Feminino , Humanos , Gravidez , Vacinas Bacterianas , Colômbia , Estudos Transversais , Panamá , Peru , Vacinação , Coqueluche/prevenção & controleRESUMO
Background: Despite widespread vaccination, pertussis has re-emerged as a serious public health concern worldwide. Since 2017, Peru has experienced an increase in pertussis cases exhibiting a higher risk of severity and death in young infants. Thus, a dose of the tetanus, diphtheria, and acellular pertussis (Tdap) vaccine is recommended for pregnant women in the third trimester. Although evidence suggests the maternal Tdap vaccine is safe and effective, its association with a reduced risk of pertussis in developing countries remains poorly investigated. Methods: We conducted a case-control study to evaluate the association between Tdap vaccination during pregnancy and reduction in the risk of pertussis among infants aged <2 months in Peru. Pertussis cases and controls treated in healthcare facilities nationwide between 2019 and 2021 and confirmed by real-time polymerase chain reaction were included. The controls were randomly selected from test-negative patients. Odds ratios (ORs) and vaccine effectiveness (VE) were calculated using a multiple logistic regression model and 1 - (OR) × 100%, respectively. Results: Fifty cases and 150 controls were included in the analysis. The mothers of 4% of cases and 16.7% of controls received Tdap vaccination during pregnancy, resulting in an OR of 0.19 (95% confidence interval [CI], .04-.86) and VE of 81% (95% CI, 14%-96%) for preventing pertussis in infants. Conclusions: Peruvian infants <2 months old whose mothers received the Tdap vaccine in the third trimester of pregnancy had a significantly lower risk of pertussis. The Tdap vaccination is thus an effective intervention to reduce the burden of pertussis in at-risk populations.
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INTRODUCTION: For pregnant women, vaccination with inactivated influenza vaccine (IIV) and tetanus, diphtheria, acellular pertussis vaccine (Tdap) is recommended. In Peru, uptake is nonetheless low. A study was conducted to identify factors affecting maternal vaccination coverage. The study's primary objectives were to describe the knowledge, attitudes, and practices regarding maternal immunization among pregnant/postpartum women and health care professionals (HCPs). The secondary objective was to determine the vaccination coverage and the impact of Ministry of Health (MOH) recommendations. METHODS: An observational multicenter, cross-sectional survey study was conducted from February 1, 2021 to June 30, 2021 in five cities in Peru. Two surveys were conducted to assess knowledge, attitudes, and practices concerning maternal immunization: one among pregnant/postpartum women and one among HCPs. RESULTS: Participants were 668 pregnant/postpartum women with a mean age of 29.6 years and 219 HCPs-mostly midwives (46.6%) and obstetricians/gynecologists (44.7%). Of the pregnant/postpartum women, 66.9% knew that, in general, vaccinations are given for prevention, and 98.5% believed vaccines are important. Nonetheless, 69.6% of pregnant/postpartum women had poor or moderate knowledge of maternal vaccination. Disease knowledge of influenza (89.1%) and tetanus (87.0%) was high, while knowledge of pertussis (37.7%) was low. Women agreed/strongly agreed that they would get vaccinated with Tdap if a doctor (96.3%), midwife (88.9%), or nurse (72.0%) recommended it. Of the HCPs, 81.3% routinely recommended Tdap vaccination for pregnant women. CONCLUSIONS: To enhance vaccine acceptance in pregnant women in Peru, we must improve knowledge of the diseases, MOH recommendations, and benefits of the offered vaccinations. HCPs could provide this vaccination knowledge and information along with their vaccination recommendation as the pregnant/postpartum women indicated they would take the vaccines if recommended by their HCPs. Our findings are important for the successful implementation of maternal immunization programs in Peru.
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BACKGROUND: Maternal vaccination is safe and provides protection against COVID-19 in mothers and neonates, and it is necessary to evaluate its effect on the induction of immune responses through the levels of neutralizing antibodies present in maternal and neonatal blood. METHODS: An observational study with transversal analysis was carried out. Included in the research were neonates (<1 month) whose mothers had been immunized whilst pregnant with at least one dose of the vaccine BNT16b and had not shown any symptoms of COVID-19. The blood of the mothers and newborns was collected during the Guthrie test and sent to the laboratory for the detection of neutralizing antibodies against SARS-CoV-2. RESULTS: A total of 162 pairs of mothers and neonates were analyzed with an average age of 26.3 ± 5.97 years and 13.4 ± 6.90 days, respectively. All samples collected present neutralizing antibodies with an average percentage of 91% in the mothers and 92% in the neonates. The most satisfactory immune response was observed in neonates and mothers vaccinated during the second trimester of gestation. CONCLUSIONS: The vaccination of expectant mothers with the immunizer BNT162b2 has promoted a robust immunological response in both the mothers and the neonates.
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BACKGROUND: There is an urgent need for active safety surveillance to monitor vaccine exposure during pregnancy in low- and middle-income countries (LMICs). Existing maternal, newborn, and child health (MNCH) data collection systems could serve as platforms for post-marketing active surveillance of maternal immunization safety. To identify sites using existing systems, a thorough assessment should be conducted. Therefore, this study had the objectives to first develop an assessment tool and then to pilot this tool in sites using MNCH data collection systems through virtual informant interviews. METHODS: We conducted a rapid review of the literature to identify frameworks on population health or post-marketing drug surveillance. Four frameworks that met the eligibility criteria were identified and served to develop an assessment tool capable of evaluating sites that could support active monitoring of vaccine safety during pregnancy. We conducted semi-structured interviews in six geographical sites using MNCH data collection systems (DHIS2, INDEPTH, and GNMNHR) to pilot domains included in the assessment tool. RESULTS: We developed and piloted the "VPASS (Vaccines during Pregnancy - sites supporting Active Safety Surveillance) assessment tool" through interviews with nine stakeholders, including central-level systems key informants and site-level managers from DHIS2 and GNMNHR; DHIS2 in Kampala (Uganda) and Kigali (Rwanda); GNMNHR from Belagavi (India) and Lusaka (Zambia); and INDEPTH from Nanoro (Burkina Faso) and Manhica (Mozambique). The tool includes different domains such as the system's purpose, the scale of implementation, data capture and confidentiality, type of data collected, the capability of integration with other platforms, data management policies and data quality monitoring. Similarities among sites were found regarding some domains, such as data confidentiality, data management policies, and data quality monitoring. Four of the six sites met some domains to be eligible as potential sites for active surveillance of vaccinations during pregnancy, such as a routine collection of MNCH individual data and the capability of electronically integrating individual MNCH outcomes with information related to vaccine exposure during pregnancy. Those sites were: Rwanda (DHIS2), Manhica (IN-DEPTH), Lusaka (GNMNHR), and Belagavi (GNMNHR). CONCLUSION: This study's findings should inform the successful implementation of active safety surveillance of vaccines during pregnancy by identifying and using active individual MNCH data collection systems in LMICs.
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Países em Desenvolvimento , Vacinas , Gravidez , Recém-Nascido , Criança , Feminino , Humanos , Zâmbia , Ruanda , Uganda , Vacinas/efeitos adversos , Confiabilidade dos DadosRESUMO
Human milk constitutes a secretion with unique functions of both nourishing the nursling and providing protection against enteric and respiratory infections, mainly due to its content of secretory IgA antibodies but also due to the presence of a plethora of bioactive factors. Specific IgA antibodies are produced locally by plasma cells derived from B lymphocytes that migrate from other mucosae to the mammary gland during lactation, particularly from the gastrointestinal and respiratory tracts. Therefore, here, the authors will provide a comprehensive review of the content and functions of different nutritional and bioactive anti-infectious components from breast milk, such as oligosaccharides, lactoferrin, haptocorrin, α-lactalbumin, k-casein, lysozyme, lactoperoxidase, mucin, fatty acids, defensins, cytokines and chemokines, hormones and growth factors, complement proteins, leukocytes and nucleic acids, including microRNAs, among many others, and the induction of antibody responses in breast milk after maternal vaccination with several licensed vaccines, including the anti-SARS-CoV-2 vaccine preparations used worldwide. Currently, in the midst of the pandemic, maternal vaccination has re-emerged as a crucial source of passive immunity to the neonate through the placenta and breastfeeding, considering that maternal vaccination can induce specific antibodies if performed during pregnancy and after delivery. There have been some reports in the literature about milk IgA antibodies induced by bacterial antigens or inactivated virus vaccines, such as anti-diphtheria-tetanus-pertussis, anti-influenza viruses, anti-pneumococcal and meningococcal polysaccharide preparations. Regarding anti-SARS-CoV-2 vaccines, most studies demonstrate elevated levels of specific IgA and IgG antibodies in milk with virus-neutralizing ability after maternal vaccination, which represents an additional approach to improve the protection of the nursling during the entire breastfeeding period.
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COVID-19 , Leite Humano , Aleitamento Materno , Feminino , Humanos , Imunoglobulina A , Recém-Nascido , Gravidez , VacinaçãoRESUMO
BACKGROUND: The effect of pneumococcal vaccination of mothers with human immunodeficiency virus (HIV) on infant responses to childhood vaccination has not been studied. We compared the immunogenicity of 10-valent pneumococcus conjugate vaccine (PCV-10) in HIV-exposed uninfected infants born to mothers who received PCV-10, 23-valent pneumococcus polysaccharide vaccine (PPV-23), or placebo during pregnancy. METHODS: Antibody levels against 7 serotypes were measured at birth, before the first and second doses of PCV-10m and after completion of the 2-dose regimen in 347 infants, including 112 born to mothers who received PPV-23, 112 who received PCV-10, and 119 who received placebo during pregnancy. Seroprotection was defined by antibody levels ≥0.35 µg/mL. RESULTS: At birth and at 8 weeks of life, antibody levels were similar in infants born to PCV-10 or PPV-23 recipients and higher than in those born to placebo recipient. After the last dose of PCV-10, infants in the maternal PCV-10 group had significantly lower antibody levels against 5 serotypes than those in the maternal PPV-23 group and against 3 serotypes than those in the maternal placebo group, and they did not have higher antibody levels against any serotype. The seroprotection rate against 7 serotypes was 50% in infants in the maternal PCV-10 group, compared with 71% in both of the maternal PPV-23 and placebo groups (Pâ <â .001). CONCLUSIONS: Administration of PCV-10 during pregnancy was associated with decreased antibody responses to PCV-10 and seroprotection rates in infants. Considering that PCV-10 and PPV-23 had similar immunogenicity in pregnant women with HIV and that administration of PPV-23 did not affect the immunogenicity of PCV-10 in infants, PPV-23 in pregnancy may be preferred over PCV-10.
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Infecções por HIV , Infecções Pneumocócicas , Anticorpos Antibacterianos/uso terapêutico , Feminino , HIV , Infecções por HIV/tratamento farmacológico , Humanos , Lactente , Recém-Nascido , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas , Polissacarídeos , Gravidez , Streptococcus pneumoniae , Vacinação , Vacinas ConjugadasRESUMO
Abstract Human milk constitutes a secretion with unique functions of both nourishing the nursling and providing protection against enteric and respiratory infections, mainly due to its content of secretory IgA antibodies but also due to the presence of a plethora of bioactive factors. Specific IgA antibodies are produced locally by plasma cells derived from B lymphocytes that migrate from other mucosae to the mammary gland during lactation, particularly from the gastrointestinal and respiratory tracts. Therefore, here, the authors will provide a comprehensive review of the content and functions of different nutritional and bioactive anti-infectious components from breast milk, such as oligosaccharides, lactoferrin, haptocorrin, α-lactalbumin, k-casein, lysozyme, lactoperoxidase, mucin, fatty acids, defensins, cytokines and chemokines, hormones and growth factors, complement proteins, leukocytes and nucleic acids, including microRNAs, among many others, and the induction of antibody responses in breast milk after maternal vaccination with several licensed vaccines, including the anti-SARS-CoV-2 vaccine preparations used worldwide. Currently, in the midst of the pandemic, maternal vaccination has re-emerged as a crucial source of passive immunity to the neonate through the placenta and breastfeeding, considering that maternal vaccination can induce specific antibodies if performed during pregnancy and after delivery. There have been some reports in the literature about milk IgA antibodies induced by bacterial antigens or inactivated virus vaccines, such as anti-diphtheria-tetanus-pertussis, anti-influenza viruses, anti-pneumococcal and meningococcal polysaccharide preparations. Regarding anti-SARS-CoV-2 vaccines, most studies demonstrate elevated levels of specific IgA and IgG antibodies in milk with virus-neutralizing ability after maternal vaccination, which represents an additional approach to improve the protection of the nursling during the entire breastfeeding period.
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Maternal immunization is key to protecting maternal and newborn health. We interviewed pregnant women in Brazil to identify barriers to and enablers of maternal immunization in the country. In-depth interviews and focus groups were conducted in Brazil with 60 pregnant women from São Paulo and Rio de Janeiro at different stages of their pregnancies. Participants were encouraged to discuss views on safety, efficacy and importance of maternal vaccines, access to vaccines, interactions with healthcare professionals, and sources of information on vaccine-related matters. There was generally a positive regard for maternal immunization among the interviewed women, many of whom associated vaccination with protection of their unborn child. The interviewees cited several reasons for adherence to immunization guidelines, including recommendations from healthcare professionals, targeted communication campaigns, and active use of a vaccination card or booklet. There were no reported barriers for maternal vaccines. Some women using private healthcare services reported not having been asked about vaccines at check-ups, which could adversely affect vaccination rates. A rumour that vaccines caused microcephaly which emerged during the Zika outbreak was the most commonly cited reason for choosing not to vaccinate among the interviewees. This study identified important vaccine confidence builders. Many of the interviewees critically reflected upon information received, placing themselves as the decision makers over their health choices. A prominent barrier to maternal immunization was a rumour linking vaccines to microcephaly. To the best of our knowledge, this has not been previously reported in the literature and requires further investigation into the extent of this issue and how it can be mitigated.
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Vacinas , Infecção por Zika virus , Zika virus , Brasil , Criança , Surtos de Doenças , Feminino , Humanos , Recém-Nascido , Gravidez , Vacinação , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/prevenção & controleRESUMO
BACKGROUND: Maternal vaccination is key to decreasing maternal and infant mortality globally. Yet perceptions about maternal vaccines and immunization among pregnant women are often understudied, particularly in low- and middle- income countries. This qualitative study explored trust, views, and attitudes towards maternal immunization among pregnant women in Mexico. A total of 54 women from Mexico City and Toluca participated in the in-depth interviews and focus groups. We explored participants' experiences with maternal vaccination, as well as how they navigated the health system, searched for information, and made decisions around maternal immunization. RESULTS: Our findings point to issues around access and quality of maternal healthcare, including immunizations services. While healthcare professionals were recognized for their expertise, participants reported not receiving enough information to make informed decisions and used online search engines and digital media to obtain more information about maternal healthcare. Some participants held strong doubts over the benefits of vaccination and were hesitant about the safety and efficacy of maternal vaccines. These concerns were also shared by pregnant women who had been vaccinated. Some participants disclosed low levels of trust in government and vaccination campaigns. CONCLUSION: Pregnant women, soon to be parents and making vaccination decisions for their child, constitute an important target group for policymakers seeking optimal maternal as well as childhood immunization coverage. Our findings highlight the importance of targeted communication, trust-building and engagement strategies to strengthen confidence in immunization amongst this group.
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Internet , Confiança , Criança , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Lactente , México , Aceitação pelo Paciente de Cuidados de Saúde , Gravidez , VacinaçãoRESUMO
BACKGROUND: Maternal immunization rates and vaccine uptake in Latin America vary from country to country. This variability stems from factors related to pregnant women, vaccine recommendations from healthcare providers and the health system. The aim of this paper is to describe women's knowledge and attitudes to maternal immunziation, and barriers to access and vaccination related decision-making processes in Latin American countries. METHODS: We conducted focus group discussions (FGD) with pregnant women in five middle-income countries: Argentina, Brazil, Honduras, Mexico and Peru, between July 2016 and July 2018. The FGDs were conducted by trained qualitative researchers in diverse clinics located in the capital cities of these countries. RESULTS: A total of 162 pregnant women participated in the FGDs. In general, participants were aware of the recommendation to receive vaccines during pregnancy but lacked knowledge regarding the diseases prevented by these vaccines. Pregnant women expressed a desire for clearer and more detailed communication on maternal vaccines by their healthcare professionals instead of relying on other sources of information such as the internet. Overall, participants had positive attitudes towards maternal immunization and were open to receiving vaccines in pregnancy based on general trust they have in recommendations made by their healthcare providers. The main obstacles pregnant women said they encounter were mainly centered around their clinical experience: long waiting times, vaccine shortages, and impolite behavior of healthcare providers or clinical staff. CONCLUSION: Important advances have been made in Latin America to promote maternal immunization. Results from this study show that an important aspect that remains to be addressed, and is crucial in improving vaccine uptake in pregnancy, is women's clinical experience. We recommend pregnant women to be treated as a priority population for providing immunization and related healthcare education. It is imperative to train healthcare providers in health communication so they can effectively communicate with pregnant women regarding maternal vaccines and can fill knowledge gaps that otherwise might be covered by unreliable sources dispensing inaccurate information.
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Gestantes , Vacinação , Argentina , Brasil , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Honduras , Humanos , Imunização , América Latina , México , Aceitação pelo Paciente de Cuidados de Saúde , Peru , GravidezRESUMO
This issue of Vaccine is devoted to papers from a research project that developed two types of simulation models, static and dynamic transmission, to evaluate the cost-effectiveness of maternal immunization to prevent pertussis in infants in low- and middle-income countries (LMICs). The research was conducted by a multinational team of investigators and funded by the Bill & Melinda Gates Foundation to gain an understanding of when and where maternal immunization might be a good public health investment for LMICs. Here we review the project's central lessons for vaccine policy and research. Models require a lot of data. As most LMICs lack good data, the models were built using pertussis disease burden data from Brazil, a middle-income country with three long-established, independent information systems (disease surveillance, hospitalization, and mortality), on the hypothesis that the disease process is similar across countries. Values for key parameters, particularly infant mortality, infant vaccine coverage, and costs of vaccination and treatment, were then varied to represent other LMICs. The results show that coverage levels of infant whole cell pertussis (wP) vaccine are key to the cost-effectiveness of maternal pertussis immunization. In settings where infant wP coverage is below the threshold thought necessary to eliminate pertussis in the population, 90-95%, maternal immunization is cost-effective, even cost-saving. By contrast, it is very expensive in countries capable of maintaining infant vaccination in or above the threshold range. The research also suggests that, while static models may serve to explore an intervention's cost-effectiveness initially, dynamic transmission models are essential for more accurate estimates. These findings can help guide policies toward maternal pertussis immunization, but also show that developing better data on neonatal pertussis mortality burden and infant vaccine coverage in LMICs, and on the duration of immunity of currently available pertussis vaccines, are key priorities to support better vaccine policy.
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Coqueluche , Brasil , Análise Custo-Benefício , Países em Desenvolvimento , Humanos , Imunização , Programas de Imunização , Lactente , Vacina contra Coqueluche , Vacinação , Coqueluche/prevenção & controleRESUMO
OBJECTIVES: Using dynamic transmission models we evaluated the health and cost outcomes of adding acellular pertussis (aP) vaccination of pregnant women to infant vaccination in three Brazilian states that represent different socioeconomic conditions. The primary objective was to determine whether the same model structure could be used to represent pertussis disease dynamics in differing socioeconomic conditions. METHODS: We tested three model structures (SIR, SIRS, SIRSIs) to represent population-level transmission in three socio-demographically distinct Brazilian states: São Paulo, Paraná and Bahia. Two strategies were evaluated: infant wP vaccination alone versus maternal aP immunization plus infant wP vaccination. Model projections for 2014-2029 include outpatient and inpatient pertussis cases, pertussis deaths, years of life lost, disability-adjusted life-years (DALYs) lost, and costs (in 2014 USD) of maternal aP vaccination, infant vaccination, and pertussis medical treatment. Incremental cost per DALY averted is presented from the perspective of the Brazilian National Health System. RESULTS: Based on goodness-of-fit statistics, the SIRSIs model fit best, although it had only a modest improvement in statistical quantitative assessments relative to the SIRS model. For all three Brazilian states, maternal aP immunization led to higher costs but also saved infant lives and averted DALYs. The 2014 USD cost/DALY averted was $3068 in Sao Paulo, $2962 in Parana, and $2022 in Bahia. These results were robust in sensitivity analyses with the incremental cost-effectiveness ratios exceeding per capita gross regional product only when the probability that a pertussis case is reported was assumed higher than base case implying more overt cases and deaths and therefore more medical costs. CONCLUSIONS: The same model structure fit all three states best, supporting the idea that the disease behaves similarly across different socioeconomic conditions. We also found that immunization of pregnant women with aP is cost-effective in diverse Brazilian states.
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Coqueluche , Brasil , Análise Custo-Benefício , Feminino , Humanos , Imunização , Lactente , Gravidez , Fatores Socioeconômicos , Vacinação , Coqueluche/prevenção & controleRESUMO
BACKGROUND: This paper compares cost-effectiveness results from two models of maternal immunization to prevent pertussis in infants in Brazil, one static, one dynamic, to explore when static models are adequate for public health decisions and when the extra effort required by dynamic models is worthwhile. METHODS: We defined two scenarios to explore key differences between static and dynamic models, herd immunity and time horizon. Scenario 1 evaluates the incremental cost/DALY of maternal acellular pertussis (aP) immunization as routine infant vaccination coverage ranges from low/moderate up to, and above, the threshold at which herd immunity begins to eliminate pertussis. Scenario 2 compares cost-effectiveness estimates over the models' different time horizons. Maternal vaccine prices of $9.55/dose (base case) and $1/dose were evaluated. RESULTS: The dynamic model shows that maternal immunization could be cost-saving as well as life-saving at low levels of infant vaccination coverage. When infant coverage reaches the threshold range (90-95%), it is expensive: the dynamic model estimates that maternal immunization costs $2 million/DALY at infant coverage > 95% and maternal vaccine price of $9.55/dose; at $1/dose, cost/DALY is $200,000. By contrast, the static model estimates costs/DALY only modestly higher at high than at low infant coverage. When the models' estimates over their different time horizons are compared at infant coverage < 90-95%, their projections fall in the same range. CONCLUSIONS: Static models may serve to explore an intervention's cost-effectiveness against infectious disease: the direction and principal drivers of change were the same in both models. When, however, an intervention too small to have significant herd immunity effects itself, such as maternal aP immunization, takes place against a background of vaccination in the rest of the population, a dynamic model is crucial to accurate estimates of cost-effectiveness. This finding is particularly important in the context of widely varying routine infant vaccination rates globally. CLINICAL TRIAL REGISTRY: Clinical Trial registry name and registration number: Not applicable.
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Coqueluche , Brasil , Análise Custo-Benefício , Humanos , Imunização , Programas de Imunização , Lactente , Vacina contra Coqueluche , Vacinação , Coqueluche/prevenção & controleRESUMO
BACKGROUND: Antenatal care providers have a key role in providing appropriate information and immunization recommendations to improve pregnant women's vaccine uptake. The objective of this study is to describe health care providers' perspectives and experience regarding the implementation of maternal immunization programs in Latin America. METHODS: We conducted 33 in-depth interviews of health care providers from Argentina, Brazil, Honduras, Mexico, and Peru (6-7 per country). Qualitative data analysis was conducted using a combination of both manual techniques and the computer software program NVivo. We identified and coded main themes related to maternal immunization. RESULTS: The main themes identified in this analysis were practices related to maternal immunization, knowledge and training, resource availability and interactions with pregnant women. Healthcare providers knew that recommendations exists but some did not know their content; they expressed concerns about insufficient training. Providers from all five countries expressed the need for additional human resources and supplies. They also expressed a desire for women to be more proactive and ask more questions during the health visits. CONCLUSION: This is the first multi-country study assessing the perspectives of health care providers about maternal immunization practices at the facility level in Latin America. Recommendations based on the results from this study include implementing additional trainings around maternal immunization, especially targeting obstetricians and midwives. These trainings should be conducted in coordination with improvements to supply chain and other structural issues.
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Pessoal de Saúde , Imunização , Argentina , Brasil , Feminino , Honduras , Humanos , América Latina , México , Peru , Gravidez , Cuidado Pré-NatalRESUMO
BACKGROUND: Maternal immunization has the potential to reduce both maternal and infant morbidity and mortality by protecting women from complications during pregnancy as well as conferring protection for babies who are too young to be vaccinated. Limited evidence is available about the drivers of maternal immunization in middle-income countries such as Peru. Vaccines against tetanus, diphtheria and influenza are recommended beginning in the second trimester in Peru; however, vaccination coverage has remained low in Peru compared to other countries in the region. As additional vaccines are recommended for administration in pregnancy, a better understanding of the perceptions and attitudes of pregnant women that influence vaccination are needed to design communication materials. METHODS: We conducted an exploratory qualitative study to understand the individual level factors influencing pregnant women's vaccine uptake. We interviewed pregnant women about their knowledge, perceptions and experiences with vaccination during pregnancy. Community health workers recruited women in a peri urban area of Peru in April 2018. RESULTS: Twelve women were interviewed, the majority of which had received vaccination during the current pregnancy. The most common reasons for vaccination were to protect the baby and because vaccines are effective. Concerns included vaccine safety during pregnancy and adverse effects on the unborn baby. Some women mentioned that because vaccines are given later in pregnancy, the unborn baby is stronger, so vaccines will not harm them. Women highlighted that the main reason for not being vaccinated was lack of information. They also noted that they were the decision-maker in whether or not they were vaccinated. Most women said that they trusted healthcare providers and that trust was linked to providing information through open communication. CONCLUSIONS: Overall, participants were supportive of maternal vaccination. They believed that vaccines were effective in protecting both their unborn baby and themselves. The main reason given for non-vaccination was lack of knowledge about vaccination in pregnancy. The strong desire expressed by study participants to get more information presents an opportunity for immunization programs to develop interventions that facilitate better information dissemination to pregnant women to increase vaccination uptake.
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Vacinas contra Influenza , Influenza Humana , Feminino , Humanos , Lactente , Aceitação pelo Paciente de Cuidados de Saúde , Percepção , Peru , Gravidez , Gestantes , VacinaçãoRESUMO
BACKGROUND: The Region of the Americas has a long history of implementing maternal and neonatal immunization (MNI) programs. Our study aimed to understand the state of MNI policies, strategies and implementation practices in Latin America (LA). METHODS: Study conducted in 5 middle-income countries: Argentina, Brazil, Honduras, Mexico and Peru. The methods included a desk review, interviews with national stakeholders and health care providers, focus groups with pregnant women and observations in health facilities. Enablers and barriers were identified and categorized as individual, societal or related to the health system. RESULTS: All 5 participating countries had similar MNI policies and high access to antenatal care. Key enablers were the high acceptability of vaccination during pregnancy, high-level of political will and a national legal framework ensuring free access to vaccines. At the health system level, implementation was facilitated by the existence of immunization advisory committees, a pooled vaccine procurement mechanism, complementary vaccine delivery strategies, conditional cash transfer to users and performance incentives to health facilities. The main programmatic barriers were the lack of adequate MNI information; limited coordination between antenatal and immunization services; inadequate supply, resources and infrastructure; high staff turnover; insufficient training for health care providers; and weak monitoring and reporting systems. CONCLUSION: Middle-income countries in LA have successfully implemented MNI programs and several enablers were identified. To overcome remaining barriers, there is a need to focus on improving the "immunization journey" for pregnant women through providing more clear and timely information to users and providers; removing barriers to access; ensuring adequate supply, human resources and infrastructure; making the health service experience positive; and establishing integrated information systems that allow for monitoring the progress toward achieving MNI goals. Strengthening the MNI programs can also improve equitable access to health services and prepare for the introduction of future vaccines for pregnant women.
Assuntos
Imunização , Vacinação , América , Argentina , Brasil , Países em Desenvolvimento , Feminino , Honduras , Humanos , Programas de Imunização , Recém-Nascido , América Latina , México , Peru , GravidezRESUMO
BACKGROUND: Maternal immunization with tetanus, diphtheria, and acellular pertussis (Tdap) vaccine confers protection to young infants. We aimed to describe trends in pertussis incidence and associated mortality in children aged <12 months before and after introduction of maternal Tdap immunization in Bogotá, Colombia. METHODS: Data on pertussis-related cases/deaths in infants aged <12 months were collected from SIVIGILA for the period 2005-2016, and compared incidence for the pre-vaccine introduction (2005-2012) and post-maternal Tdap vaccination (2014-2016) periods in infants aged <12 months and in three distinct age-strata; ≤6 weeks, 7-<28 weeks, and 28-52 weeks. Mortality comparisons were performed in all infants <12 months. RESULTS: From 2005 to 2016, 2315 laboratory or clinically-confirmed pertussis cases were reported in infants <12 months of age (278 cases in young infants aged ≤6 weeks); 55 pertussis deaths were reported in children aged <12 months. No pertussis deaths were reported in the 2014-2016 period. Since maternal Tdap introduction in 2013, a consistent decline in pertussis incidence and mortality was observed. In the time-series analysis, incidence declined from 209.4/100,000 persons (2005-2012) to 49.1/100,000 persons (2014-2016) in all children <12 months; a 87.5% (95%CI: 77.2-93.2%) reduction. For these same period's incidence in young infants ≤6 weeks declined from 196.7 to 89.6/100,000 person-years (an 54.4% [95% CI: 35.4-67.9%] reduction). Greater incidence reductions were observed in older infants; 73.4% (95% CI: 68.4-77.6%) in those aged 7-<28 weeks, and 100% in those aged 28-52 weeks. A 100% reduction in Pertussis mortality in infants <12 months was observed. Since Tdap introduction, maternal vaccine coverage rose from <60% in 2013-2015 to 80% in 2016. CONCLUSIONS: Implementation of maternal immunization in Bogotá may have contributed to the reduction in pertussis incidence and mortality among infants <12 months of age (ClinicalTrials.gov: NCT02569879). An Audio Summary linked to this article that can be found on Figshare https://doi.org/10.6084/m9.figshare.12943316.
Assuntos
Vacinas contra Difteria, Tétano e Coqueluche Acelular , Coqueluche , Adulto , Idoso , Criança , Colômbia/epidemiologia , Humanos , Incidência , Lactente , Recém-Nascido , Vacinação em Massa , Pessoa de Meia-Idade , Vacinação , Coqueluche/epidemiologia , Coqueluche/prevenção & controleRESUMO
BACKGROUND: In 2011, Argentina experienced its highest pertussis incidence and mortality rates of the last decade; 60% of deaths were among infants aged <2 months. In response, a dose of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine was recommended for all pregnant women at ≥20 weeks of gestation. Although recent studies suggest that maternal Tdap vaccination is effective at preventing infant disease, no data have come from low- or middle-income countries, nor from ones using whole-cell pertussis vaccines for primary immunization. METHODS: We conducted a matched case-control evaluation to assess the effectiveness of maternal Tdap vaccination in preventing pertussis among infants aged <2 months in Argentina. Pertussis case patients identified from September 2012 to March 2016 at 6 hospital sites and confirmed by polymerase chain reaction testing were included. Five randomly selected controls were matched to each case patient by hospital site and mother's health district. We used multivariable conditional logistic regression to calculate odds ratios (ORs). Vaccine effectiveness (VE) was estimated as (1 - OR) × 100%. RESULTS: Seventy-one case patients and 300 controls were included in the analysis. Forty-nine percent of case patients and 78% of controls had mothers who were vaccinated during pregnancy. Overall Tdap VE was estimated at 80.7% (95% confidence interval, 52.1%-92.2%). We found similar VE whether Tdap was administered during the second or third trimester. CONCLUSIONS: Tdap vaccination during pregnancy is effective in preventing pertussis in infants aged <2 months in Argentina, with similar effectiveness whether administered during the second or third trimester of pregnancy.