Cessation of Trivalent Oral Poliovirus Vaccine and Introduction of Inactivated Poliovirus Vaccine - Worldwide, 2016.

Since the 1988 World Health Assembly resolution to eradicate poliomyelitis, transmission of the three types of wild poliovirus (WPV) has been sharply reduced (1). WPV type 2 (WPV2) has not been detected since 1999 and was declared eradicated in September 2015. Because WPV type 3 has not been detected since November 2012, WPV type 1 (WPV1) is likely the only WPV that remains in circulation (1). This marked progress has been achieved through widespread use of oral poliovirus vaccines (OPVs), most commonly trivalent OPV (tOPV), which contains types 1, 2, and 3 live, attenuated polioviruses and has been a mainstay of efforts to prevent polio since the early 1960s. However, attenuated polioviruses in OPV can undergo genetic changes during replication, and in communities with low vaccination coverage, can result in vaccine-derived polioviruses (VDPVs) that can cause paralytic polio indistinguishable from the disease caused by WPVs (2). Among the 721 polio cases caused by circulating VDPVs (cVDPVs*) detected during January 2006-May 2016, type 2 cVDPVs (cVDPV2s) accounted for >94% (2). Eliminating the risk for polio caused by VDPVs will require stopping all OPV use. The first stage of OPV withdrawal involved a global, synchronized replacement of tOPV with bivalent OPV (bOPV) containing only types 1 and 3 attenuated polioviruses, planned for April 18-May 1, 2016, thereby withdrawing OPV type 2 from all immunization activities (3). Complementing the switch from tOPV to bOPV, introduction of at least 1 dose of injectable, trivalent inactivated poliovirus vaccine (IPV) into childhood immunization schedules reduces risks from and facilitates responses to cVDPV2 outbreaks. All 155 countries and territories that were still using OPV in immunization schedules in 2015 have reported that they had ceased use of tOPV by mid-May 2016.(†) As of August 31, 2016, 173 (89%) of 194 World Health Organization (WHO) countries included IPV in their immunization schedules.(§) The cessation of tOPV use is a major milestone toward the global goal of eradicating polio; however, careful surveillance for polioviruses and prompt, aggressive responses to polio outbreaks are still needed to realize a polio-free world.

Determinants of stunting in Indonesian children: evidence from a cross-sectional survey indicate a prominent role for the water, sanitation and hygiene sector in stunting reduction.

BACKGROUND: Stunting in early life has considerable human and economic costs. The purpose of the study was to identify factors associated with stunting among children aged 0-23 months in Indonesia to inform the design of appropriate policy and programme responses. METHODS: Determinants of child stunting, including severe stunting, were examined in three districts in Indonesia using data from a cross-sectional survey conducted in 2011. A total of 1366 children were included. The analysis used multiple logistic regression to determine unadjusted and adjusted odds ratios. RESULTS: The prevalence of stunting and severe stunting was 28.4 % and 6.7 %, respectively. The multivariate analysis on determinants of stunting identified a significant interaction between household sanitary facility and household water treatment (P for interaction = 0.007) after controlling for potential covariates: in households that drank untreated water, the adjusted odds on child stunting was over three times higher if the household used a unimproved latrine (adjusted odds ratio 3.47, 95 % confidence interval 1.73-7.28, P <0.001); however, in households that drank treated water, the adjusted odds on child stunting was not significantly higher if the household used an unimproved latrine (adjusted odds ratio 1.27, 95 % confidence interval 0.99-1.63, P = 0.06). Other significant risk factors included male sex, older child age and lower wealth quintile. The risk factors for severe stunting included male sex, older child age, lower wealth quintile, no antenatal care in a health facility, and mother's participation in decisions on what food was cooked in the household. CONCLUSIONS: The combination of unimproved latrines and untreated drinking water was associated with an increased odds on stunting in Indonesia compared with improved conditions. Policies and programmes to address child stunting in Indonesia must consider water, sanitation and hygiene interventions. Operational research is needed to determine how best to converge and integrate water, sanitation and hygiene interventions into a broader multisectoral approach to reduce stunting in Indonesia.

Rapid monitoring in vaccination campaigns during emergencies: the post-earthquake campaign in Haiti.

PROBLEM: The earthquake that struck Haiti in January 2010 caused 1.5 million people to be displaced to temporary camps. The Haitian Ministry of Public Health and Population and global immunization partners developed a plan to deliver vaccines to those residing in these camps. A strategy was needed to determine whether the immunization targets set for the campaign were achieved. APPROACH: Following the vaccination campaign, staff from the Ministry of Public Health and Population interviewed convenience samples of households - in specific predetermined locations in each of the camps - regarding receipt of the emergency vaccinations. A camp was targeted for "mop-up vaccination" - i.e. repeat mass vaccination - if more than 25% of the children aged 9 months to 7 years in the sample were found not to have received the emergency vaccinations. LOCAL SETTING: Rapid monitoring was implemented in camps located in the Port-au-Prince metropolitan area. Camps that housed more than 5000 people were monitored first. RELEVANT CHANGES: By the end of March 2010, 72 (23%) of the 310 vaccinated camps had been monitored. Although 32 (44%) of the monitored camps were targeted for mop-up vaccination, only six of them had received such repeat mass vaccination when checked several weeks after monitoring. LESSONS LEARNT: Rapid monitoring was only marginally beneficial in achieving immunization targets in the temporary camps in Port-au-Prince. More research is needed to evaluate the utility of conventional rapid monitoring, as well as other strategies, during post-disaster vaccination campaigns that involve mobile populations, particularly when there is little capacity to conduct repeat mass vaccination.

Economic evaluation of a Child Health Days strategy to deliver multiple maternal and child health interventions in Somalia.

INTRODUCTION: Child Health Days (CHDs) are increasingly used by countries to periodically deliver multiple maternal and child health interventions as time-limited events, particularly to populations not reached by routine health services. In countries with a weak health infrastructure, this strategy could be used to reach many underserved populations with an integrated package of services. In this study, we estimate the incremental costs, impact, cost-effectiveness, and return on investment of 2 rounds of CHDs that were conducted in Somalia in 2009 and 2010. METHODS: We use program costs and population estimates reported by the World Health Organization and United Nations Children's Fund to estimate the average cost per beneficiary for each of 9 interventions delivered during 2 rounds of CHDs implemented during the periods of December 2008 to May 2009 and August 2009 to April 2010. Because unstable areas were unreachable, we calculated costs for targeted and accessible beneficiaries. We model the impact of the CHDs on child mortality using the Lives Saved Tool, convert these estimates of mortality reduction to life years saved, and derive the cost-effectiveness ratio and the return on investment. RESULTS: The estimated average incremental cost per intervention for each targeted beneficiary was $0.63, with the cost increasing to $0.77 per accessible beneficiary. The CHDs were estimated to save the lives of at least 10,000, or 500,000 life years for both rounds combined. The CHDs were cost-effective at $34.00/life year saved. For every $1 million invested in the strategy, an estimated 615 children's lives, or 29,500 life years, were saved. If the pentavalent vaccine had been delivered during the CHDs instead of diphtheria-pertussis-tetanus vaccine, an additional 5000 children's lives could have been saved. CONCLUSIONS: Despite high operational costs, CHDs are a very cost-effective service delivery strategy for addressing the leading causes of child mortality in a conflict setting like Somalia and compare favorably with other interventions rated as health sector "best buys" in sub-Saharan Africa.

Should outbreak response immunization be recommended for measles outbreaks in middle- and low-income countries? An update.

BACKGROUND: Measles caused mortality in >164,000 children in 2008, with most deaths occurring during outbreaks. Nonetheless, the impact and desirability of conducting measles outbreak response immunization (ORI) in middle- and low-income countries has been controversial. World Health Organization guidelines published in 1999 recommended against ORI in such settings, although recently these guidelines have been reversed for countries with measles mortality reduction goals. METHODS: We searched literature published during 1995-2009 for papers reporting on measles outbreaks. Papers identified were reviewed by 2 reviewers to select those that mentioned ORI. World Bank classification of country income was used to identify reports of outbreaks in middle- and low-income countries. RESULTS: We identified a total of 485 articles, of which 461 (95%) were available. Thirty-eight of these papers reported on a total of 38 outbreaks in which ORI was used. ORI had a clear impact in 16 (42%) of these outbreaks. In the remaining outbreaks, we were unable to independently assess the impact of ORI. CONCLUSIONS: These findings generally support ORI in middle- and low-income countries. However, the decision to conduct ORI and the nature and extent of the vaccination response need to be made on a case-by-case basis.

Laboratory characterization of measles virus infection in previously vaccinated and unvaccinated individuals.

Waning immunity or secondary vaccine failure (SVF) has been anticipated by some as a challenge to global measles elimination efforts. Although such cases are infrequent, measles virus (MeV) infection can occur in vaccinated individuals following intense and/or prolonged exposure to an infected individual and may present as a modified illness that is unrecognizable as measles outside of the context of a measles outbreak. The immunoglobulin M response in previously vaccinated individuals may be nominal or fleeting, and viral replication may be limited. As global elimination proceeds, additional methods for confirming modified measles cases may be needed to understand whether SVF cases contribute to continued measles virus (MeV) transmission. In this report, we describe clinical symptoms and laboratory results for unvaccinated individuals with acute measles and individuals with SVF identified during MeV outbreaks. SVF cases were characterized by the serological parameters of high-avidity antibodies and distinctively high levels of neutralizing antibody. These parameters may represent useful biomarkers for classification of SVF cases that previously could not be confirmed as such using routine laboratory diagnostic techniques.

Immunization programs to support primary health care and achieve universal health coverage.

Gains in immunization coverage and delivery of primary health care service have stagnated in recent years. Remaining gaps in service coverage reflect multiple underlying reasons that may be amenable to improved health system design. Immunization systems and other primary health care services can be mutually supportive, for improved service delivery and for strengthening of Universal Health Coverage. Improvements require that dynamic and multi-faceted barriers and risks be addressed. These include workforce availability, quality data systems and use, leadership and management that is innovative, flexible, data driven and responsive to local needs. Concurrently, improvements in procurement, supply chain, logistics and delivery systems, and integrated monitoring of vaccine coverage and epidemiological disease surveillance with laboratory systems, and vaccine safety will be needed to support community engagement and drive prioritized actions and communication. Finally, political will and sustained resource commitment with transparent accountability mechanisms are required. The experience of the impact of COVID-19 pandemic on essential PHC services and the challenges of vaccine roll-out affords an opportunity to apply lessons learned in order to enhance vaccine services integrated with strong primary health care services and universal health coverage across the life course.

Pro-equity immunization and health systems strengthening strategies in select Gavi-supported countries.

BACKGROUND: Achieving universal immunization coverage and reaching every child with life-saving vaccines will require the implementation of pro-equity immunization strategies, especially in poorer countries. Gavi-supported countries continue to implement and report strategies that aim to address implementation challenges and improve equity. This paper summarizes the first mapping of these strategies from country reports. METHODS: Thirteen Gavi-supported countries were purposively selected with emphasis on Gavi's priority countries. Following a scoping of different documents submitted to Gavi by countries, 47 Gavi Joint Appraisals (JAs) for the period 2016-2019 from the 13 selected countries were included in the mapping. We used a consolidated framework synthesized from 16 different equity and health systems frameworks, which incorporated UNICEF's coverage and equity assessment approach - an adaptation of the Tanahashi model. Using search terms, the mapping was conducted using a combination of manual search and the MAXQDA qualitative analysis tool. Pro-equity strategies meeting the inclusion criteria were identified and compiled in an Excel database, and then populated on a tableau visualization dashboard. RESULTS: In total, 258 pro-equity strategies were implemented by the 13 sampled Gavi-supported countries between 2016 and 2019. The framework determinants of social norms, utilization, and management and coordination accounted for more than three-quarters of all pro-equity strategies implemented in these countries. The median number of strategies reported per country was 17. Afghanistan, Nigeria, and Uganda reported the highest number of strategies that we considered as pro-equity. CONCLUSION: Findings from this mapping can be useful in addressing equity gaps, reaching partially immunized, and 'zero-dose' vaccinated children, and valuable resource for countries planning to implement pro-equity strategies, especially as immunization stakeholders reimagine immunization delivery in light of COVID-19, and as Gavi finalizes its fifth organizational strategy. Future efforts should seek to identify pro-equity strategies being implemented across additional countries, and to assess the extent to which these strategies have improved immunization coverage and equity.

Challenges in measuring measles case fatality ratios in settings without vital registration.

Measles, a highly infectious vaccine-preventable viral disease, is potentially fatal. Historically, measles case-fatality ratios (CFRs) have been reported to vary from 0.1% in the developed world to as high as 30% in emergency settings. Estimates of the global burden of mortality from measles, critical to prioritizing measles vaccination among other health interventions, are highly sensitive to the CFR estimates used in modeling; however, due to the lack of reliable, up-to-date data, considerable debate exists as to what CFR estimates are appropriate to use. To determine current measles CFRs in high-burden settings without vital registration we have conducted six retrospective measles mortality studies in such settings. This paper examines the methodological challenges of this work and our solutions to these challenges, including the integration of lessons from retrospective all-cause mortality studies into CFR studies, approaches to laboratory confirmation of outbreaks, and means of obtaining a representative sample of case-patients. Our experiences are relevant to those conducting retrospective CFR studies for measles or other diseases, and to those interested in all-cause mortality studies.

Measles deaths in Nepal: estimating the national case-fatality ratio.

OBJECTIVE: To estimate the case-fatality ratio (CFR) for measles in Nepal, determine the role of risk factors, such as political instability, for measles mortality, and compare the use of a nationally representative sample of outbreaks versus routine surveillance or a localized study to establish the national CFR (nCFR). METHODS: This was a retrospective study of measles cases and deaths in Nepal. Through two-stage random sampling, we selected 37 districts with selection probability proportional to the number of districts in each region, and then randomly selected within each district one outbreak among all those that had occurred between 1 March and 1 September 2004. Cases were identified by interviewing a member of each and every household and tracing contacts. Bivariate analyses were performed to assess the risk factors for a high CFR and determine the time from rash onset until death. Each factor's contribution to the CFR was determined through multivariate logistic regression. From the number of measles cases and deaths found in the study we calculated the total number of measles cases and deaths for all of Nepal during the study period and in 2004. FINDINGS: We identified 4657 measles cases and 64 deaths in the study period and area. This yielded a total of about 82 000 cases and 900 deaths for all outbreaks in 2004 and a national CFR of 1.1% (95% confidence interval, CI: 0.5-2.3). CFR ranged from 0.1% in the eastern region to 3.4% in the mid-western region and was highest in politically insecure areas, in the Ganges plains and among cases < 5 years of age. Vitamin A treatment and measles immunization were protective. Most deaths occurred during the first week of illness. CONCLUSION: To our knowledge, this is the first CFR study based on a nationally representative sample of measles outbreaks. Routine surveillance and studies of a single outbreak may not yield an accurate nCFR. Increased fatalities associated with political insecurity are a challenge for health-care service delivery. The short period from disease onset to death and reduced mortality from treatment with vitamin A suggest the need for rapid, field-based treatment early in the outbreak.

Laboratory confirmation of measles in elimination settings: experience from the Republic of the Marshall Islands, 2003.

OBJECTIVE: To highlight the complications involved in interpreting laboratory tests of measles immunoglobulin M (IgM) for confirmation of infection during a measles outbreak in a highly vaccinated population after conducting a mass immunization campaign as a control measure. METHODS: This case study was undertaken in the Republic of the Marshall Islands during a measles outbreak in 2003, when response immunization was conducted. A measles case was defined as fever and rash and one or more of cough, coryza or conjunctivitis. Between 13 July and 7 November 2003, serum samples were obtained from suspected measles cases for serologic testing and nasopharyngeal swabs were taken for viral isolation by reverse transcriptase polymerase chain reaction (RT-PCR). FINDINGS: Specimens were collected from 201 suspected measles cases (19% of total): of the ones that satisfied the clinical case definition, 45% were IgM positive (IgM+) and, of these, 24% had received measles vaccination within the previous 45 days (up to 45 days after vaccination an IgM+ result could be due to either vaccination or wild-type measles infection). The proportion of IgM+ results varied with clinical presentation, the timing of specimen collection and vaccination status. Positive results on RT-PCR occurred in specimens from eight IgM-negative and four IgM+ individuals who had recently been vaccinated. CONCLUSION: During measles outbreaks, limiting IgM testing to individuals who meet the clinical case definition and have not been recently vaccinated allows for measles to be confirmed while conserving resources.

Health and immunisation services for the urban poor in selected countries of Asia.

BACKGROUND: Asia is a region that is rapidly urbanising. While overall urban health is above rural health standards, there are also pockets of deep health and social disadvantage within urban slum and peri-urban areas that represent increased public health risk. With a focus on vaccine preventable disease and immunisation coverage, this commentary describes and analyses strengths and weaknesses of existing urban health and immunisation strategy, with a view to recommending strategic directions for improving access to immunisation and related maternal and child health services in urban areas across the region. The themes discussed in this commentary are based on the findings of country case studies published by the United Nations Childrens Fund (UNICEF)  on the topic of immunisation and related health services for the urban poor in Cambodia, Indonesia, Mongolia, Myanmar, the Philippines, and Vietnam. MAIN BODY: Although overall urban coverage is higher than rural coverage in selected countries of Asia, there are also wide disparities in coverage between socio economic groups within urban areas. Consistent with these coverage gaps, there is emerging evidence of outbreaks of vaccine preventable diseases in urban areas. In response to this elevated public health risk, there have been some promising innovations in operational strategy in urban settings, although most of these initiatives are project related and externally funded. Critical issues for attention for urban health services access include reaching consensus on accountability for management and resourcing of the strategy, and inclusion of an urban poor approach within the planning and budgeting procedures of Ministries of Health and local governments. Advancement of local partnership and community engagement strategies to inform operational approaches for socially marginalised populations are also urgently required. Such developments will be reliant on development of municipal models of primary health care that have clear delegations of authority, adequate resources and institutional capabilities to implement. CONCLUSIONS: The development of urban health systems and immunisation strategy is required regionally and nationally, to respond to rapid demographic change, social transition, and increased epidemiological risk.

Enhancing immunization during second year of life by reducing missed opportunities for vaccinations in 46 countries.

BACKGROUND: Delivering vaccination services during the second year of life (2YL)1 provides countries with an opportunity to achieve greater coverage, to provide booster doses and vaccines missed during the first year of life, as well as contribute towards disease control and elimination goals. METHODS: Using data from demographic health surveys (DHSs) conducted during 2010 to 2016, this paper explores the proportion of missed opportunities for vaccinations generally provided during routine immunization among children in their 2YL. RESULTS: DHS data in 46 countries surveyed 478,737 children, from which 169,259 children were 12-23 months old and had vaccination/health cards viewed by surveyors. From this group, 69,489 children aged 12-23 months had contact with health services in their 2YL. Three scenarios for a missed opportunity for vaccinations were analysed: (1) a child received one vaccine in the immunization schedule and was eligible for another vaccine, but did not receive any further vaccination, (2) a child received a vitamin A supplementation (VAS) and was due for a vaccine, but did not receive vaccines that were due, and (3) a child was taken to a health facility for a sick visit and was due (and eligible) for a vaccine, but did not receive the vaccine. A total of 16,409 (24%) children had one or more missed opportunities for vaccinations. CONCLUSION: This analysis highlights the magnitude of the problem of missed opportunities in the 2YL. The global community needs to provide better streamlined guidance, policies and strategies to promote vaccination screenings at well-child and sick child visits in the 2YL. Where they do not exist, well-child visits in the 2YL should be established and strengthened.

District team problem solving as an approach to district health programme planning: a review, and survey of its status in selected districts in Indonesia.

District team problem solving (DTPS) was developed by WHO in the 1980s to explicitly engage local stakeholders in decentralized planning and, in later iterations, budgeting of health services. It became WHO's global flagship approach to district-level health priority-setting and planning. DTPS entails multisectoral stakeholders (the team) using local data to prioritize and fund services, and should enhance capacity in management of decentralized healthcare. From the late 1990s, DTPS evolved through several phases in Indonesia. Multiple donors supported its use for planning maternal and child health (MCH) services, with substantive national government input, despite no formal assessment of its sustained uptake or benefits. In the context of new interest to promote DTPS for MCH in Indonesia, we assessed its status there in 2013-14, focussing on its implementation status and on associated MCH data collection (PWS-KIA). We used mixed methods to capture local challenges to and opportunities for DTPS in seven sub-national locations in 6 of Indonesia's 31 provinces. DTPS remained active only in the two locations whose local government ever allocated funds to the process; in the others, it stopped once the initial non-government funding ceased. An official decree establishing DTPS and team membership was only issued in four locations, and it was not evident that the intended multisectoral representation was achieved in any site. Trained DTPS facilitators remained available in only four locations. In all districts, interviewees described PWS-KIA as potentially serving a revived DTPS, but insufficiently robust to underwrite local advocacy for investment in MCH. Although efforts to introduce DTPS as a uniform approach to district MCH planning in Indonesia have not been sustained, strong commitment to evidence-based planning remains. Decentralized health planning processes require quality data, local government buy-in and associated funding, and should link explicitly to broader administrative planning processes and budget cycles.

Case-fatality rate during a measles outbreak in eastern Niger in 2003.

BACKGROUND: The World Health Organization (WHO) estimates that the case-fatality rate (CFR) for measles in West Africa is 4%-6%. In Niger, 50,138 measles cases and 201 deaths (CFR, 0.4%) were reported in 2003. We conducted an investigation to determine the epidemiology and the true CFR of measles in the Mirriah district in Niger. METHODS: Twenty-two villages from the Mirriah district that reported measles cases in 2003 were included in the investigation. A comprehensive household search for measles cases and deaths was conducted, and serum samples from 12 villages were collected for laboratory confirmation. A measles case was defined as illness characterized by fever, rash, and either cough, coryza, or conjunctivitis, with rash onset during the period from 1 January 2003 to 15 April 2003. Deaths occurring within 30 days after rash onset were attributed to measles unless they were obviously due to other causes. RESULTS: Measles was confirmed serologically in all villages from which samples were collected. Of 945 case patients identified, 900 (95.2%) were aged <15 years, 114 (12.3%) were vaccinated, and 789 (83.5%) sought treatment at a health care facility. A total of 92 deaths were attributed to measles (CFR, 9.7%; 95% confidence interval, 7.9%-11.5%). The CFR was highest in infants aged <1 year (15.6%). Households with >or=2 case patients had a higher CFR (10.8%) than that of households with only 1 case patient (6.0%). Households consisting of >or=8 members had a CFR of 12.8%, whereas the CFR of smaller households was 7.1%. CONCLUSIONS: This investigation suggests that the measles CFR in the Mirriah district may be 2-fold higher than the WHO regional estimate and 20-fold higher than the estimate derived from routine surveillance. Reducing measles mortality in Niger will require wide-age-range vaccination campaigns, improvement in routine immunization services, and periodic "follow-up" campaigns.

Measles outbreak in the Republic of the Marshall Islands, 2003.

BACKGROUND: Measles is a highly contagious viral infection. Measles transmission can be prevented through high population immunity (>or=95%) achieved by measles vaccination. In the Republic of the Marshall Islands (RMI), no measles cases were reported during 1989-2002; however, a large measles outbreak occurred in 2003. Reported 1-dose measles vaccine coverage among children aged 12-23 months varied widely (52-94%) between 1990 and 2000. METHODS: RMI is a Pacific island nation (1999 population: 50,840). A measles case was defined as fever, rash, and cough, or coryza, or conjunctivitis, in an RMI resident between July 13 and November 7, 2003. A vaccination campaign was used for outbreak control. RESULTS: Of the 826 reported measles cases, 766 (92%) occurred in the capital (Majuro). There were 186 (23%) cases in infants aged <1 year and 309 (37%) of cases in persons aged >or=15 years. The attack rate was highest among infants (Majuro atoll: 213 cases/1,000 infants). Among cases aged 1-14 years, 281 (59%) reported no measles vaccination before July 2003. There were 100 hospitalizations and 3 deaths. The measles H1 genotype was identified. The vaccination campaign resulted in 93% coverage among persons aged 6 months to 40 years. Interpretation Populations without endemic measles transmission can accumulate substantial susceptibility and be at risk for large outbreaks when measles virus is imported. 'Islands' of measles susceptibility may develop in infants, adults, and any groups with low vaccine coverage. To prevent outbreaks, high population immunity must be sustained by maintaining and documenting high vaccine coverage.