Immunization is a proven and cost-effective public health intervention, saving the lives of millions of children and protecting millions more from illness and disability. Immunization is also a wise financial investment - with every $1 invested in immunization returning an estimated $16 in health-care savings and increased economic productivity. Most countries in Europe and Central Asia have immunization coverage of 95 percent or more for three doses of diphtheria, tetanus and pertussis (DTP), often seen as the measure of national performance on immunization. However, while most national averages for DTP vaccination may be adequate, the regional average is hovering at around 92 percent, a slight decrease from the previous year, which is not high enough to ensure immunity for everyone. Over 70 percent of the region’s unvaccinated infants are from middle income countries, with Ukraine presenting the lowest coverage rate and the greatest challenge. National averages also mask disparities, with Roma children and those from other ethnic and vulnerable groups, including refugee and migrant children, all lagging behind. Measles outbreaks are a growing problem. Last year there were over 10,000 cases of measles in the region. Despite increased coverage of the first dose of the measles vaccine among children (up from 63 percent in 2000 to 93 percent in 2016) more work is urgently needed, as children are not fully protected against measles unless they receive two doses. Currently, second dose coverage is at 88 percent, which does not provide adequate protection. In total, over 500,000 children in the region are still not protected against measles - a life-threatening, but easily preventable disease. There are also concerns about ‘vaccine hesitancy’ – a growing mistrust of immunization among some parents, fuelled by myths and misinformation. Such hesitancy may stem from negative media stories linking a child’s death to immunization without the full facts. It may be influenced by the region’s anti-vaccine movements, which spread anti-immunization messages. Meanwhile, measures to counter vaccine hesitancy and build parental trust in immunization are hampered by a lack of discussion with parents about its importance and the minimal risks. A baby girl receives her vaccination at a clinic in Serbia. A baby girl receives her vaccination at a clinic in Serbia. Donor support for immunization is falling in some countries that still require such support. Elsewhere, the concern is to ensure financial sustainability for immunization programmes once countries ‘graduate’ from the support provided by Gavi (The Vaccine Alliance). Ongoing reforms in some countries are affecting both the structure and financing of immunization programmes. Some countries, challenged by competing priorities at home and inaccessibly priced vaccines on the global market, experienced several vaccine shortages in 2015–2016, sometimes causing critical disruptions of services. These issues are particularly acute in middle-income countries, many of which self-procure vaccines and continue to face significant challenges in achieving financial sustainability of their immunization programmes. Some countries also lack adequate monitoring of vaccine coverage, which is critical to understand and address any gaps. As a result of such challenges, the region faces outbreaks of vaccine-preventable disease, such as a polio outbreak in 2015 and an ongoing measles outbreak in Ukraine – a country where conflict and economic recession have depleted stocks of vaccines and vaccine hesitancy is reducing immunization coverage. There is also an ongoing large measles outbreak in Romania, with over 10,000 cases of the diseases and 38 deaths. During the last five years, measles outbreaks have been registered in Georgia (2013), Kazakhstan (2014), Kyrgyzstan (2015), and Tajikistan (2017). Outbreaks in one country can spread rapidly to others, signalling the interdependence and vulnerability of all countries, whatever their stage of economic development.