Stephen Sosler

A Long-Lasting Measles Epidemic in Maroua, Cameroon 2008–2009: Mass Vaccination as Response to the Epidemic

BACKGROUND A measles outbreak occurred in Maroua, Cameroon, from January 2008 to April 2009. In accordance with recent World Health Organization guidelines, an outbreak-response immunization (ORI) was conducted in January 2009. The aim of this study was to investigate the causes of the epidemic in order to guide vaccination strategies. METHODS We performed a stratified household-based survey using cluster sampling to determine measles vaccination coverage in children aged 9 months to 15 years. We defined 3 strata based on measles incidence. Next, we performed a case-control study to measure vaccine effectiveness (VE). Cases were obtained from health center registries. Controls were selected among respondents to the coverage survey. RESULTS The vaccination-coverage survey included 2963 children in total. The overall routine vaccination coverage was 74.1% (95% confidence interval [CI]: 70.0%-78.3%). Measles incidence was inversely proportional to routine vaccination coverage, with high incidence associated with coverage of 71% and low incidence associated with coverage of 84%. The overall VE was 94% (95% CI, 86.7%-97.4%). After the ORI in January 2009, the coverage was >90% in all strata and measles incidence declined rapidly. DISCUSSION Our results confirm that insufficient vaccination coverage was the main reason for this epidemic. The ORI conducted in January 2009 contributed both to control the epidemic and to increase the vaccination coverage to desirable levels.

Seroprevalence of measles and natural rubella antibodies among children in Bangui, Central African Republic

BackgroundPassively acquired maternal antibodies are necessary to protect infants against circulating measles virus until they reach the eligible age of vaccination. Likewise, high levels of population immunity must be achieved and maintained to reduce measles virus transmission. This study was undertaken to (1) assess the presence of maternally acquired measles-specific IgG antibodies among infants less than 9 months of age in Bangui, Central African Republic and (2) determine the immune status of vaccination-age children and the concordance with reported vaccination status. A secondary objective was to describe the presence of rubella-specific IgG antibody in the study population.MethodsVaccination history and blood samples were collected from 395 children using blotting paper. Samples were analyzed for the presence of measles-specific IgG antibodies using commercial ELISA kits.ResultsMeasles-specific IgG antibodies were detected in 51.3% of vaccinated children and 27.6% of non-vaccinated children. Maternally derived measles IgG antibodies were present in only 14.8% of infants aged 0-3 months and were absent in all infants aged 4-8 months. The presence of IgG-specific measles antibodies varied among children of vaccination age, from 57.3% for children aged 9 months to 5 years, to 50.6% for children aged 6-9 years and 45.6% for chidren aged 10 years and above. The overall prevalence of rubella-specific IgG was 55.4%, with a high prevalence (87.4%) among children over 10 years of age.ConclusionThe findings suggest that despite efforts to accelerate measles control by giving a second dose of measles vaccine, a large number of children remain susceptible to measles virus. Further research is required to determine the geographic extent of immunity gaps and the factors that influence immunity to measles virus in the Central African Republic.

Transition Planning For After Polio Eradication

Abstract The Global Polio Eradication Initiative (GPEI) has been in operation since 1988, now spends

Case Based Measles Surveillance in Pune: Evidence to Guide Current and Future Measles Control and Elimination Efforts in India

1 billion annually, and operates through thousands of staff and millions of volunteers in dozens of countries. It has brought polio to the brink of eradication. After eradication is achieved, what should happen to the substantial assets, capabilities, and lessons of the GPEI? To answer this question, an extensive process of transition planning is underway. There is an absolute need to maintain and mainstream some of the functions, to keep the world polio-free. There is also considerable risk—and, if seized, substantial opportunity—for other health programs and priorities. And critical lessons have been learned that can be used to address other health priorities. Planning has started in the 16 countries where GPEI’s footprint is the greatest and in the program’s 5 core agencies. Even though poliovirus transmission has not yet been stopped globally, this planning process is gaining momentum, and some plans are taking early shape. This is a complex area of work—with difficult technical, financial, and political elements. There is no significant precedent. There is forward motion and a willingness on many sides to understand and address the risks and to explore the opportunities. Very substantial investments have been made, over 30 years, to eradicate a human pathogen from the world for the second time ever. Transition planning represents a serious intent to responsibly bring the world’s largest global health effort to a close and to protect and build upon the investment in this effort, where appropriate, to benefit other national and global priorities. Further detailed technical work is now needed, supported by broad and engaged debate, for this undertaking to achieve its full potential.

Monitoring Results in Routine Immunization: Development of Routine Immunization Dashboard in Selected African Countries in the Context of the Polio Eradication Endgame Strategic Plan

Background According to WHO estimates, 35% of global measles deaths in 2011 occurred in India. In 2013, India committed to a goal of measles elimination by 2020. Laboratory supported case based measles surveillance is an essential component of measles elimination strategies. Results from a case-based measles surveillance system in Pune district (November 2009 through December 2011) are reported here with wider implications for measles elimination efforts in India. Methods Standard protocols were followed for case identification, investigation and classification. Suspected measles cases were confirmed through serology (IgM) or epidemiological linkage or clinical presentation. Data regarding age, sex, vaccination status were collected and annualized incidence rates for measles and rubella cases calculated. Results Of the 1011 suspected measles cases reported to the surveillance system, 76% were confirmed measles, 6% were confirmed rubella, and 17% were non-measles, non-rubella cases. Of the confirmed measles cases, 95% were less than 15 years of age. Annual measles incidence rate was more than 250 per million persons and nearly half were associated with outbreaks. Thirty-nine per cent of the confirmed measles cases were vaccinated with one dose of measles vaccine (MCV1). Conclusion Surveillance demonstrated high measles incidence and frequent outbreaks in Pune where MCV1 coverage in infants was above 90%. Results indicate that even high coverage with a single dose of measles vaccine was insufficient to provide population protection and prevent measles outbreaks. An effective measles and rubella surveillance system provides essential information to plan, implement and evaluate measles immunization strategies and monitor progress towards measles elimination.

Experiences and Lessons From Polio Eradication Applied to Immunization in 10 Focus Countries of the Polio Endgame Strategic Plan

Background To monitor immunization-system strengthening in the Polio Eradication Endgame Strategic Plan 2013–2018 (PEESP), the Global Polio Eradication Initiative identified 1 indicator: 10% annual improvement in third dose of diphtheria-tetanus-pertussis–containing vaccine (DTP3) coverage in polio high-risk districts of 10 polio focus countries. Methods A multiagency team, including staff from the African Region, developed a comprehensive list of outcome and process indicators measuring various aspects of the performance of an immunization system. Results The development and implementation of the dashboard to assess immunization system performance allowed national program managers to monitor the key immunization indicators and stratify by high-risk and non–high-risk districts. Discussion Although only a single outcome indicator goal (at least 10% annual increase in DTP3 coverage achieved in 80% of high-risk districts) initially existed in the endgame strategy, we successfully added additional outcome indicators (eg, decreasing the number of DTP3-unvaccinated children) as well as program process indicators focusing on cold chain, stock availability, and vaccination sessions to better describe progress on the pathway to raising immunization coverage. Conclusion When measuring progress toward improving immunization systems, it is helpful to use a comprehensive approach that allows for measuring multiple dimensions of the system.

Cluster Survey Evaluation of a Measles Vaccination Campaign in Jharkhand, India, 2012

Abstract Nine polio areas of expertise were applied to broader immunization and mother, newborn and child health goals in ten focus countries of the Polio Eradication Endgame Strategic Plan: policy & strategy development, planning, management and oversight (accountability framework), implementation & service delivery, monitoring, communications & community engagement, disease surveillance & data analysis, technical quality & capacity building, and partnerships. Although coverage improvements depend on multiple factors and increased coverage cannot be attributed to the use of polio assets alone, 6 out of the 10 focus countries improved coverage in three doses of diphtheria tetanus pertussis containing vaccine between 2013 and 2015. Government leadership, evidence-based programming, country-driven comprehensive operational annual plans, community partnership and strong accountability systems are critical for all programs and polio eradication has illustrated these can be leveraged to increase immunization coverage and equity and enhance global health security in the focus countries.

Population level assessments of immunization-when more complex is better

Introduction India was the last country in the world to implement a two-dose strategy for measles-containing vaccine (MCV) in 2010. As part of measles second-dose introduction, phased measles vaccination campaigns were conducted during 2010–2013, targeting 131 million children 9 months to <10 years of age. We performed a post-campaign coverage survey to estimate measles vaccination coverage in Jharkhand state. Methods A multi-stage cluster survey was conducted 2 months after the phase 2 measles campaign occurred in 19 of 24 districts of Jharkhand during November 2011–March 2012. Vaccination status of children 9 months to <10 years of age was documented based on vaccination card or mother’s recall. Coverage estimates and 95% confidence intervals (95% CI) for 1,018 children were calculated using survey methods. Results In the Jharkhand phase 2 campaign, MCV coverage among children aged 9 months to <10 years was 61.0% (95% CI: 54.4–67.7%). Significant differences in coverage were observed between rural (65.0%; 95% CI: 56.8–73.2%) and urban areas (45.6%; 95% CI: 37.3–53.9%). Campaign awareness among mothers was low (51.5%), and the most commonly reported reason for non-vaccination was being unaware of the campaign (69.4%). At the end of the campaign, 53.7% (95% CI: 46.5–60.9%) of children 12 months to <10 years of age received ≥2 MCV doses, while a large proportion of children remained under-vaccinated (34.0%, 95% CI: 28.0–40.0%) or unvaccinated (12.3%, 95% CI: 9.3–16.2%). Conclusions Implementation of the national measles campaign was a significant achievement towards measles elimination in India. In Jharkhand, campaign performance was below the target coverage of ≥90% set by the Government of India, and challenges in disseminating campaign messages were identified. Efforts towards increasing two-dose MCV coverage are needed to achieve the recently adopted measles elimination goal in India and the South-East Asia region.

An assessment of hepatitis B vaccine introduction in India: Lessons for roll out and scale up of new vaccines in immunization programs

It is estimated that more than 10 million children in India do not receive BCG, 3 doses of OPV and DTP, and measles vaccine during their first year of life and more than 3 million of these do not receive any immunizations[1]. The complexity and diversity of India means that the distribution of unvaccinated and partially vaccinated children is not equal either between or within states. How immunization performance gaps are bridged is of interest to all stakeholders – Union and State governments and immunization partners. Bihar, India’s second more populous state historically competed for the inauspicious distinction of having the lowest immunization coverage rates in the country. To be certain, times have changed and Bihar’s progress to improve vaccination coverage over the past several years has been considerable. For these reasons, the assessment by Goel and colleagues of Bihar’s Muskaan Ek Abhiyan campaign [2] is timely and welcome.