Global Immunization Strategic Framework 2011–2015: Progress, Aims, and Challenges
Although progress was made during 2006–2010 in reducing global morbidity and mortality from VPDs, key overarching aims and challenges in global immunization remain for CDC to address during 2011–2015.
Polio: Since the Global Polio Eradication Initiative (GPEI) began in 1988, the number of polio cases around the world has fallen by more than 99%, from more than 350,000 cases that year to 1979 cases in 2005 and to fewer than 1300 cases in 2010. Transmission of wild poliovirus (WPV) type 2 has been eliminated since 1999, and indigenous transmission of WPV types 1 (WPV1) and 3 (WPV3) has been eliminated from all but four countries (Afghanistan, India, Nigeria, and Pakistan) since 2005. However, progress slowed since 2005, with ongoing WPV1 and WPV3 transmission in all endemic countries and the re-establishment of transmission in four previously polio-free countries (Angola, Chad, Democratic Republic of the Congo, and Sudan). This led to the development of a new GPEI strategic plan for 2010–2012, which incorporates lessons learned and introduces specific new strategies, milestones for monitoring progress, and enhanced oversight mechanisms for taking corrective actions. The objectives are to interrupt WPV transmission by the end of 2012 and to certify global polio eradication by the end of 2015. CDC has been a key partner in the GPEI since 1988, providing critical technical and financial support for polio immunization activities to interrupt WPV transmission, maintain and enhance laboratory surveillance for polioviruses, monitor progress toward reaching epidemiological targets, and support development and implementation of a polio eradication research agenda with the long-term aim of stopping all global use of oral polio vaccine.
Measles and rubella: Endemic measles and rubella have been eliminated from the Western Hemisphere. To sustain and build on this achievement, CDC is working to control and eliminate measles and rubella in parts of the world responsible for disease importations into the United States. CDC is a founding member of the Measles Initiative, which has helped cut measles deaths globally by 78%, down from an estimated 733,000 deaths in 2000 to 345,000 deaths in 2005 and to 164,000 deaths in 2008. This decline played a major role in overall declines in child mortality during the past decade. However, gains in reducing measles mortality are fragile. Since 2009, more than 30 African countries have experienced measles outbreaks resulting from gaps in routine measles vaccination coverage and a failure to continue with timely, high-quality follow-up measles campaigns. Substantial ongoing technical and financial support will be required to attain and sustain further mortality reduction and to reach regional elimination goals that have the potential to eventually result in measles eradication. Measles-related efforts are closely linked with efforts to increase use of rubella-containing vaccines to prevent congenital rubella syndrome, which affects an estimated 110,000 infants born each year in developing countries, and to monitor progress toward achieving and maintaining rubella control and elimination goals.
Hepatitis B: In the United States, use of hepatitis B vaccine (HepB) in childhood immunization programs has decreased hepatitis B incidence more than 90%; however, approximately 40,000 immigrants with chronic hepatitis B virus (HBV) infection are admitted each year to the United States from other countries. Globally, chronic HBV infections cause an estimated 620,000 deaths annually from cirrhosis and liver cancer. CDC provides technical assistance designed to increase the number of countries using HepB in childhood immunization programs, including use of a birth dose to prevent HBV transmission from mother to infant and ultimately reduce the burden of chronic HBV infections among immigrants in the United States. In addition, CDC provides technical assistance to WHO regions and countries on monitoring progress toward achieving hepatitis B control goals.
Maternal and neonatal tetanus: Maternal and neonatal tetanus (MNT) was eliminated in the United States. Substantial progress has been made toward achieving the MNT elimination goal globally, and neonatal tetanus (NNT) deaths declined from approximately 787,000 in 1988 to 59,000 in 2008. However, as of 2010, 40 countries had yet to achieve MNT elimination in all districts. CDC provides technical assistance to many of these countries on improving tetanus immunization of pregnant women, maintaining and strengthening tetanus surveillance, and conducting country assessments to validate tetanus elimination.
Routine immunization: The WHO/UNICEF Global Immunization Vision and Strategy, 2006–2015 (GIVS) provides guidance to countries in strengthening routine immunization programs and vaccinating more people. GIVS aims to achieve 90% national 3-dose diphtheria-tetanus-pertussis vaccine (DTP3) coverage by age 12 months in all countries and 80% coverage in every district or equivalent administrative unit by 2010, and to sustain these levels through 2015. Estimated global DTP3 coverage in the 193 WHO member states increased from 74% in 2000 to 78% in 2005 and to 82% in 2009; DTP3 coverage in 2009 reflects vaccination of 107.1 million infants with three doses of DTP vaccine (14.6 million more than in 2000). However, an estimated 23.2 million children worldwide—almost 20% of the children born each year—did not receive three doses of DTP vaccine during the first year of life in 2009; 70% of these infants live in 10 countries, with approximately half in India (37%) and Nigeria (14%). A recent review of published literature found that immunization program weakness was the leading reason that children did not complete the 3-dose DTP vaccination series.
VPD surveillance and information systems: Well-functioning laboratory-based VPD surveillance systems and VPD information systems are critical for managing, monitoring, and evaluating immunization programs and assessing program impact on VPD disease burden. CDC provides technical and financial support to multiple global VPD surveillance and laboratory networks, including the Global Polio Laboratory Network, the Global Measles and Rubella Laboratory Network, the Global Influenza Surveillance Network, the Global Rotavirus Surveillance Network, and the Global Invasive Bacterial Disease Surveillance Network, as well as regional surveillance and laboratory networks for yellow fever (PAHO, AFRO), Japanese encephalitis (SEARO), and pediatric bacterial meningitis (AFRO). CDC also provides technical and operational research support to strengthen the quality and use of data from VPD surveillance and information systems.
New and underused vaccines: Despite the extraordinary progress made in reducing VPD morbidity and mortality during the past decade, the immunization agenda is unfinished. CDC actively supports the evaluation and introduction of available and underused vaccines—Hib, PCV, rotavirus, HPV, meningococcal group A, HepB birth dose, rubella, Japanese encephalitis, typhoid, cholera, and yellow fever—which have the potential to greatly reduce global VPD morbidity and mortality. CDC also actively supports research to develop new vaccines to protect against leading killers in developing countries (e.g., HIV, malaria, tuberculosis).
The time is now optimal to accelerate the introduction of Hib, PCV, and rotavirus vaccines, which can reduce the 2.9 million annual deaths due to pneumonia and diarrhea among children under age 5 years by 40%–60%. WHO has recommended introduction of these vaccines in childhood immunization programs in all countries, and the GAVI Alliance (GAVI) is committed to provide funding support for their introduction in the poorest countries. As of December 2010, Hib vaccine has been introduced in 171 countries, rotavirus vaccine in 26 countries, and PCV in 58 countries. HPV vaccine, which prevents cervical cancer caused by HPV, has been introduced in 31 countries. A new meningococcal group A vaccine was introduced in Burkina Faso in 2010. Plans are underway to introduce the vaccine in 25 African countries to eliminate epidemics of meningitis and prevent up to 123,000 deaths and 237,000 cases of disability in the Africa meningitis belt within 10 years.
Widespread introduction of new and underused vaccines still depends on addressing key challenges, including inadequate vaccine supply, low immunization system capacity, creation of sustainable partnerships to maximize synergy in reaching global goals, and high cost of newer vaccines. In addition, although WHO has recommended that countries introduce new and underused vaccines, public health officials in each country must make their own decisions based on national priorities and capacity. To facilitate country decision-making processes, CDC provides direct technical assistance on evaluating the disease burden, developing surveillance capacity, performing economic analysis, and understanding program implications and vaccine impact, and indirect assistance through participation in partnerships including GAVI and the GAVI-funded Accelerated Vaccine Initiative. CDC also provides technical support on the development of national immunization technical advisory groups.