What We Do
CDC plays a critical role in eradicating polio by providing scientific leadership and guidance at the global, regional, and country level to implement evidence-based strategies. Over the past 31 years, CDC, ministries of health, and Global Polio Eradication Initiative (GPEI) partners work together across these areas to reach every community and vaccinate every last child. As a result:
- The number of worldwide polio cases has fallen from an estimated 350,000 in 1988 to 140 in 2020—a decline of more than 99% in reported cases.
- Five of the six regions of the world are certified polio-free—the African Region, the Americas, Europe, South East Asia and the Western Pacific. Only two polio-endemic countries (nations that have never interrupted the transmission of wild poliovirus) remain—Afghanistan and Pakistan.
- Without our polio eradication efforts, more than 18 million people who are currently healthy would have been paralyzed by the virus.
We continue to provide technical assistance to endemic countries (Afghanistan and Pakistan), outbreak countries, and other high-risk countries. We focus on several key areas including data and analysis, laboratory capacity building, outbreak response and program development, routine immunization, and research and innovation.
A Model for Success: Multi-country Response Stops Middle East Polio Outbreak
The response team designed a strategic response plan to contain the outbreak to Syria and Iraq, limiting the threat of polio.
Strong surveillance plays a foundational role in helping to eliminate polio cases worldwide. In order to monitor and improve the quality of immunization campaigns, detailed records are kept and the data from those records are used to inform action and decision-making. CDC researchers and epidemiologists help to collect, analyze, and interpret the data from vaccination activities to better understand the epidemiology and guide program planning and policy development. CDC expertise in data analysis and interpretation is used at the country, regional and global level to improve the efficiency, effectiveness, and impact of global polio eradication efforts.
Since the inception of the global initiative in 1988, the CDC Polio Laboratory has helped WHO build the Global Polio Laboratory Network (GPLN) – a three-tier system of 145 laboratories worldwide – and serves as a WHO Global Specialized Reference Laboratory.
CDC’s laboratories provide critical diagnostic services, conduct genomic sequencing of polioviruses, and develop novel techniques and products that help to advance the global effort to eradicate polio. In 2018, this included the first phase of development of a novel strain of the oral polio virus. These efforts are aimed at reducing the risk of vaccine associated paralytic paralysis (VAPP) and circulating vaccine derived polioviruses (cVDPV). Other new laboratory procedures are helping countries overcome specific operational challenges, enabling more rapid detection of poliovirus, and allowing for faster response to importations or spread of virus.
Governments and health workers are at the frontline of the fight against polio. CDC experts support these efforts by providing technical assistance in outbreak response, workforce strengthening, and vaccination campaign planning and monitoring.
Polio outbreaks happen in countries that have stopped indigenous wild poliovirus but are experiencing re-infection either through the importation of wild or vaccine-derived poliovirus from another country, or the emergence and circulation of vaccine-derived poliovirus. CDC provides support to develop micro-plans to ensure services reach every community, engage community leaders in social mobilization to raise awareness of polio and immunization campaigns, train vaccination teams conducting vaccination activities, and strengthen surveillance to address any gaps.
A strong workforce is key to controlling the spread of polio and CDC helps to ensure a trained public health cadre is ready to respond. For example, CDC is working to increase surveillance sensitivity in numerous African countries through the Field Epidemiology Training Program (FETP). FETP surveillance projects in Kenya, Ethiopia, Uganda, Democratic Republic of the Congo, Togo, and others include training and logistics support to local surveillance officers, supervision by FETP graduates, and rapid increase in active surveillance to detect cases when they arise. These disease detectives will provide additional “boots on the ground” to detect and respond to suspect cases.
CDC provides technical guidance on a number of monitoring and evaluation activities such as independent monitoring of immunization campaigns, lot quality assurance sampling technique, campaign evaluation, and cold chain monitoring. Monitoring and evaluation activities provide the necessary data to drive evidence-based solutions and inform policy. For example, CDC experts are assisting the government and health workers in South Sudan on a reverse cold chain monitoring project. CDC collaborates with key partners on the ground to monitor the shipment of specimens from field to laboratory to ensure the samples are kept in good condition and delivered in a timely manner. This project will help to determine and address any major gaps in the cold chain process.
Polio is highly infectious, moving from person to person easily. Moreover, most people do not know they have the virus because they have no symptoms. To prevent the spread of poliovirus, it is imperative to vaccinate children in areas where the virus is already circulating and other areas that are at risk due to population movement. CDC and GPEI partners are actively engaged in conducting immunization activities to increase coverage and minimize the risk of further spread of the virus. Greater population immunity through routine immunization is a cornerstone of our efforts to ensure the virus does not establish or reestablish itself in populations across the world.
Poliovirus Laboratory Testing
CDC is at the forefront of applying innovative research to address complex problems that the polio eradication effort faces. Our clinical and operational research offer opportunities to take a closer look at issues such as polio vaccination dosage and schedules, as well as novel technology like drones for vaccine delivery. Results from our research have an immediate impact on how CDC and its partners operate on the ground as well as on long-term policy and strategy shifts that bring us closer to getting to zero.
Poliovirus can be detected in specimens from the throat, feces (stool), and occasionally cerebrospinal fluid (CSF) by isolating the virus in cell culture or by detecting the virus by polymerase chain reaction (PCR).
Welcome to Poliopolis –
An nOPV2 Clinical Trial
A real polio vaccine trial happened in a parking lot at the University of Antwerp, Belgium in mid-2017.