Programa nacional de inmunizacion en Chile: pasado, presente y futuro / National immunization program in Chile: past, present and future

El Programa Ampliado de Inmunizaciones (PAI) a nivel mundial nace en 1974 como iniciativa de la Organización Mundial de la Salud (OMS) y la Organización Panamericana de la Salud (OPS). En Chile, el actual Programa Nacional de Inmunizaciones (PNI) se origina en el Plan Ampliado de Inmunizaciones (PAI) establecido en el año 1978. En sus inicios, el PAI se basó en disposiciones legales definidas en 1975, que establecía las Enfermedades Trasmisibles de Vacunación Obligatoria. Desde el año 2010, el Decreto Exento N°6 promulgado el 29 de enero, se dispone la vacunación obligatoria contra enfermedades inmunoprevenibles de la población del país. Posteriormente se han realizado modificaciones al decreto exento N°6 reflejando la incorporación de nuevas vacunas al calendario, modificaciones en los grupos objetivo y/o cambios en las estrategias de vacunación, entre otros. En estas disposiciones también se establece que el Ministerio de Salud debe asegurar el acceso gratuito a vacunaciones seguras y efectivas para toda la población objetivo. El objetivo del artículo, es describir la evolución de las iniciativas de vacunación en nuestro país, desde antes de la creación del PAI, la sistematización de las estrategias de vacunación una vez que se establece el programa hasta las modificaciones realizadas en la última década.

The Expanded Program on Immunization (EPI) worldwide was created in 1974 as an initiative of the World Health Organization (WHO) and the Pan American Health Organization (PAHO). In Chile, the current National Immunization Program (PNI) originates from the Extended Inmunization Plan (EPI) established in 1978. In its beginnings, the EPI was based on legal provisions defined in 1975, which established the Communicable Diseases of Compulsory Vaccination. Since 2010, the Exempt Decree No. 6 promulgated on January 29, provides the Mandatory Vaccination against Immune preventable Diseases of the Population of the Country. Subsequently there have been modifications to the Exempt Decree No. 6 reflecting the incorporation of new vaccines to the calendar, modifications in the target groups and /or changes in vaccination strategies, among others. These provisions also state that the Ministry of Health must ensure free access to safe and effective vaccinations for the entire target population. The aim oh this article is to describe evolution of vaccination initiatives in our country, from before the creation of the EPI, the systematization of vaccination strategies once the program is established, until the modifications made in the last decade.

Elimination of Nonmedical Immunization Exemptions in California and School-Entry Vaccine Status.

BACKGROUND AND OBJECTIVES: California implemented Senate Bill 277 (SB277) in 2016, becoming the first state in nearly 30 years to eliminate nonmedical exemptions from immunization requirements for schoolchildren. Our objectives were to determine (1) the impacts of SB277 on the percentage of kindergarteners entering school not up-to-date on vaccinations and (2) if geographic patterns of vaccine refusal persisted after the implementation of the new law. METHODS: At the state level, we analyzed the magnitude and composition of the population of kindergarteners not up-to-date on vaccinations before and after the implementation of SB277. We assessed correlations between previous geographic patterns of nonmedical exemptions and patterns of the remaining entry mechanisms for kindergarteners not up-to-date after the law's implementation. RESULTS: In the first year after SB277 was implemented, the percentage of kindergartners entering school not up-to-date on vaccinations decreased from 7.15% to 4.42%. The conditional entrance rate fell from 4.43% to 1.91%, accounting for much of this decrease. Other entry mechanisms for students not up-to-date, including medical exemptions and exemptions for independent study or homeschooled students, largely replaced the decrease in the personal belief exemption rate from 2.37% to 0.56%. In the second year, the percentage of kindergartners not up-to-date increased by 0.45%, despite additional reductions in conditional entrants and personal belief exemptions. The correlational analysis revealed that previous geographic patterns of vaccine refusal persisted after the law's implementation. CONCLUSIONS: Although the percentage of incoming kindergarteners up-to-date on vaccinations in California increased after the implementation of SB277, we found evidence for a replacement effect.

Should we use Palivizumab immunoprophylaxis for infants against respiratory syncytial virus? - a cost-utility analysis.

BACKGROUND: Passive immunization against RSV (Respiratory Syncytial Virus) is given in most western countries (including Israel) to infants of high risk groups such as premature babies, and infants with Congenital Heart Disease or Congenital Lung Disease. However, immunoprophylaxis costs are extremely high ($2800-$4200 per infant). Using cost-utility analysis criteria, we evaluate whether it is justified to expand, continue or restrict nationwide immunoprophylaxis using palivizumab of high risk infants against RSV. METHODS: Epidemiological, demographic, health service utilisation and economic data were integrated from primary (National Hospitalization Data, etc.) and secondary data sources (ie: from published articles) into a spread-sheet to calculate the cost per averted disability-adjusted life year (DALY) of vaccinating various infant risk groups. Costs of intervention included antibody plus administration costs. Treatment savings and DALYs averted were estimated from applying vaccine efficacy data to relative risks of being hospitalised and treated for RSV, including possible long-term sequelae like asthma and wheezing. RESULTS: For all the groups RSV immunoprophylaxis is clearly not cost effective as its cost per averted DALY exceeds the $105,986 guideline representing thrice the per capita Gross Domestic Product. Vaccine price would have to fall by 48.1% in order to justify vaccinating Congenital Heart Disease or Congenital Lung Disease risk groups respectively on pure cost-effectiveness grounds. For premature babies of < 29 weeks, 29-32 and 33-36 weeks gestation, decreases of 36.8%, 54.5% and 83.3% respectively in vaccine price are required. CONCLUSIONS: Based solely on cost-utility analysis, at current price levels it is difficult to justify the current indications for passive vaccination with Palivizumab against RSV. However, if the manufacturers would reduce the price by 54.5% then it would be cost-effective to vaccinate the Congenital Heart Disease or Congenital Lung Disease risk groups as well as premature babies born before the 33rd week of gestation.

Factors contributing to routine immunization performance in Ethiopia, 2014.

INTRODUCTION: An increasing trend of routine immunization performance has generally been observed over the past decade in Ethiopia. However, the improvement is irregular with wide disparity among and within regions. This study analyzes health facility characteristics contribution to immunization performance in Ethiopia. METHODS: We conducted a cross-sectional study and compared characteristics of health facilities in good and poor performing zones. We used administrative coverage reports and Personal Digital Assisted (PDA) supervisory data collected by WHO EPI field officers using a standardized structured checklist. We selected 48 zones and 302 health facilities based on immunization performance data and supervisory data on potential variables. RESULTS: Logistics regression was used to identify independent contributors to good immunization performance. On logistics regression we found that: actions by higher levels in conducting supervision (Odds Ratio (OR) =4.15. 95% Confidence Interval (CI) = 1.85, 9.32, p value <0.01] and providing written feedback (Odds Ratio (OR) =4.35. 95% Confidence Interval (CI) = 2.27, 8.33, p value <0.01) , and provision of immunization services by the health facility itself for catchment population under each health unit (Odds Ratio (OR) =20.15. 95% Confidence Interval (CI) = 2.24, 181.38, p value =0.01) and absence of stock out of vaccines (Odds Ratio (OR) =0.44. 95% Confidence Interval (CI) = 0.23, 0.83, p value =0.01) are the likely significant factors contributing to good immunization performance in Ethiopia. CONCLUSION: Ensuring availability of immunization services in all health facilities, regular supervision and written feedback and improved stock management are essential factors contributing to good immunization performance.

A Second Shot at HPV.

HPV vaccination rates remain stubbornly low, and some studies show physician hesitancy about promoting the vaccine is the single biggest problem. TMA's HPV Work Group plans to coordinate with like-minded state and national organizations and agencies to come up with an action plan to improve HPV vaccination rates.

Predictors of Low Uptake of Prenatal Tetanus Toxoid, Reduced Diphtheria Toxoid, and Acellular Pertussis Immunization in Privately Insured Women in the United States.

OBJECTIVE: To examine the uptake of prenatal tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) immunization among pregnant women in the United States. METHODS: Using MarketScan data, we conducted a historical cohort study among pregnant women with employer-based commercial insurance in the United States who delivered between January 1, 2010, and December 31, 2014. We examined temporal trends of uptake, predictors of uptake, and timing of Tdap immunization. RESULTS: Among 1,222,384 eligible pregnancies in 1,147,711 women, receipt of prenatal Tdap immunization increased from 0.0% of women who delivered in January 2010 to 9.8% who delivered in October 2012 (the date of the recommendation by the Advisory Committee on Immunization Practices for Tdap during every pregnancy) to 44.4% who delivered in December 2014. Among women who received Tdap during pregnancy, the majority were immunized between 27 weeks and 36 6/7 weeks of gestation per the Advisory Committee on Immunization Practices recommendation. In multivariable analyses among women who delivered between November 2012 and December 2014, rates of prenatal Tdap immunization were lower for women younger than 25 years of age (eg, 20-24 compared with 30-34 years rate ratio [RR] 0.83, 95% confidence interval [CI] 0.85-0.88), with other children (eg, three compared with zero children: RR 0.86, 95% CI 0.84-0.88), residing in the South compared with the Midwest (RR 0.81, 95% CI 0.80-0.82), or with emergency department visits in early pregnancy (RR 0.93, 95% CI 0.92-0.95). The proportion of pregnant women who received prenatal Tdap increased with increasing gestational age at birth. CONCLUSION: By the end of 2014, fewer than half of pregnant women in the United States were receiving prenatal Tdap immunization. Implementation and dissemination strategies are needed to increase Tdap coverage among pregnant women, especially those who are young, have other children, or reside in the South.

Challenges of immunization in the African Region.

Immunization has made significant contribution to public health in the African Region, including elimination, eradication and control of life threatening diseases. Hospitalization due to vaccine preventable diseases has been drastically reduced due to introduction of new effective vaccines. However, optimizing the benefits of immunization by achieving high universal coverage has met with many challenges. The Regional immunization coverage, though raised from its low 57% in 2000 to 76% in 2015 has remained below expected target. Worse still, it has stagnated around 70% for a prolonged period. Cases of inequity in access to immunization service continue to exist in the region. This paper therefore explored the different challenges to immunization in the African Region. Some of the challenges it identifies and discusses include issues of sustainable funding and resources for immunization, vaccine stock-outs, and logistics. Others include data issues and laboratory infrastructure. The paper also attempted some possible solutions.

Forecasted trends in vaccination coverage and correlations with socioeconomic factors: a global time-series analysis over 30 years.

BACKGROUND: Incomplete immunisation coverage causes preventable illness and death in both developing and developed countries. Identification of factors that might modulate coverage could inform effective immunisation programmes and policies. We constructed a performance indicator that could quantitatively approximate measures of the susceptibility of immunisation programmes to coverage losses, with an aim to identify correlations between trends in vaccine coverage and socioeconomic factors. METHODS: We undertook a data-driven time-series analysis to examine trends in coverage of diphtheria, tetanus, and pertussis (DTP) vaccination across 190 countries over the past 30 years. We grouped countries into six world regions according to WHO classifications. We used Gaussian process regression to forecast future coverage rates and provide a vaccine performance index: a summary measure of the strength of immunisation coverage in a country. FINDINGS: Overall vaccine coverage increased in all six world regions between 1980 and 2010, with variation in volatility and trends. Our vaccine performance index identified that 53 countries had more than a 50% chance of missing the Global Vaccine Action Plan (GVAP) target of 90% worldwide coverage with three doses of DTP (DTP3) by 2015. These countries were mostly in sub-Saharan Africa and south Asia, but Austria and Ukraine also featured. Factors associated with DTP3 immunisation coverage varied by world region: personal income (Spearman's ρ=0·66, p=0·0011) and government health spending (0·66, p<0·0001) were informative of immunisation coverage in the Eastern Mediterranean between 1980 and 2010, whereas primary school completion was informative of coverage in Africa (0·56, p<0·0001) over the same period. The proportion of births attended by skilled health staff correlated significantly with immunisation coverage across many world regions. INTERPRETATION: Our vaccine performance index highlighted countries at risk of failing to achieve the GVAP target of 90% coverage by 2015, and could aid policy makers' assessments of the strength and resilience of immunisation programmes. Weakening correlations with socioeconomic factors show a need to tackle vaccine confidence, whereas strengthening correlations point to clear factors to address. FUNDING: UK Engineering and Physical Sciences Research Council.

Gavi's Transition Policy: Moving From Development Assistance To Domestic Financing Of Immunization Programs.

Gavi, the Vaccine Alliance, was created in 2000 to accelerate the introduction of new and underused vaccines in lower-income countries. The period 2000-15 was marked by the rapid uptake of new vaccines in more than seventy countries eligible for Gavi support. To stay focused on the poorest countries, Gavi's support phases out after countries' gross national income per capita surpasses a set threshold, which requires governments to assume responsibility for the continued financing of vaccines introduced with Gavi support. Gavi's funding will end in the period 2016-20 for nineteen countries that have exceeded the eligibility threshold. To avoid disrupting lifesaving immunization programs and to ensure the long-term sustainable impact of Gavi's investments, it is vital that governments succeed in transitioning from development assistance to domestic financing of immunization programs. This article discusses some of the challenges facing countries currently transitioning out of Gavi support, how Gavi's policies have evolved to help manage the risks involved in this process, and the lessons learned from this experience.

Intersectional inequalities in immunization in India, 1992-93 to 2005-06: a progress assessment.

Immunization in India is marked with stark disparities across gender, caste, wealth and place of residence with severe shortfalls among those disadvantaged in more than one dimension. In this regard, an explicit recognition of intersectionality and intersectional inequalities has 2-fold relevance; one, being the pathway of health inequality and the other being its role as a deterrent of progress particularly at higher (better) levels of health. Against this backdrop, this study examines intersectional inequalities in immunization in India and also suggests a level-sensitive progress assessment method. The study uses group analogue of Gini coefficient for highlighting the magnitude of intersectional inequality and for comprehending its association with immunization level. The results unravel the plight of vulnerable intersectional groups and draw attention to disquieting shortfalls among female SCST (scheduled castes and tribes) children from rural areas. There is also some evidence to indicate leveraging among rural males in matters of immunization and it is further discerned that such gender advantage is greater among rural non-SCST community than the rural SCST group. In concluding, the study calls for intensive immunization planning to improve coverage among vulnerable communities in both rural and urban areas.

Trends in child immunization across geographical regions in India: focus on urban-rural and gender differentials.

BACKGROUND: Although child immunization is regarded as a highly cost-effective lifesaver, about fifty percent of the eligible children aged 12-23 months in India are without essential immunization coverage. Despite several programmatic initiatives, urban-rural and gender difference in child immunization pose an intimidating challenge to India's public health agenda. This study assesses the urban-rural and gender difference in child immunization coverage during 1992-2006 across six major geographical regions in India. DATA AND METHODS: Three rounds of the National Family Health Survey (NFHS) conducted during 1992-93, 1998-99 and 2005-06 were analyzed. Bivariate analyses, urban-rural and gender inequality ratios, and the multivariate-pooled logistic regression model were applied to examine the trends and patterns of inequalities over time. KEY FINDINGS: The analysis of change over one and half decades (1992-2006) shows considerable variations in child immunization coverage across six geographical regions in India. Despite a decline in urban-rural and gender differences over time, children residing in rural areas and girls remained disadvantaged. Moreover, northeast, west and south regions, which had the lowest gender inequality in 1992 observed an increase in gender difference over time. Similarly, urban-rural inequality increased in the west region during 1992-2006. CONCLUSION: This study suggests periodic evaluation of the health care system is vital to assess the between and within group difference beyond average improvement. It is essential to integrate strong immunization systems with broad health systems and coordinate with other primary health care delivery programs to augment immunization coverage.

Applying an equity lens in the Decade of Vaccines.

Addressing inequities in immunisation must be the main priority for the Decade of Vaccines. Children who remain unreached are those who need vaccination - and other health services - most. Reaching these children and other underserved target groups will require a reorientation of current approaches and resource allocation. At the country level, evidence-based and context-specific strategies must be developed to promote equity in ways that strengthen the system that facilitates vaccination, are sustainable and extend benefits across the life cycle. At the global level, more attention must go on ensuring sustainable and affordable supply for low- and middle-income countries to vaccine products that are appropriate for the contexts where needs are greatest. Finally, data must be disaggregated and used at all levels to monitor and guide progress to reach the unreached.

Sustainability of National Immunization Programme (NIP) performance and financing following Global Alliance for Vaccines and Immunization (GAVI) support to the Democratic Republic of the Congo (DRC).

BACKGROUND: The Global Alliance for Vaccines and Immunization (GAVI) is a public-private global health partnership aiming to increase access to immunisation in poor countries. The Democratic Republic of the Congo (DRC) is the third largest recipient of GAVI funds in terms of cumulative disbursed support. We provided a comprehensive assessment of GAVI support and analysed trends in immunisation performance and financing in the DRC from 2002 to 2010. METHODS: The scope of the analysis includes GAVI's total financial support and the value of vaccines and syringes purchased by GAVI for the DRC from 2002 to 2010. Data were collected through a review of published and grey literature and interviews with key stakeholders in the DRC. We assessed the allocation and use of GAVI funds for each of GAVI's support areas, as well as trends in immunisation performance and financing. FINDINGS: DTP3 coverage increased from 2002 (38%) to 2007 (72%) but had decreased to a level below 70% in 2008 (68%) and 2010 (63%). The overall funding for vaccines increased from US$5.4 million in 2006 to US$30.5 million in 2010 (mostly from GAVI support for new vaccines). However, during the same period, the funding from national (government) and international (GAVI and other donors) sources for routine immunisation services (except vaccines) decreased from US$36.4 million to US$24.4 million. This drop in overall funding (33%) primarily affected surveillance, transport, and cold chain equipment. INTERPRETATION: GAVI support to DRC has enhanced significant progress in routine immunisation performance and financing during 2002-2010. Although progress has been partly sustained, the initial observed increase in DTP3 coverage and available funding for routine immunisation halted towards the end of the analysis period, coinciding with tetravalent and pentavalent vaccine introduction. These findings highlight the need for additional efforts to ensure the sustainability of routine immunization program performance and financing.