World Polio Day

World Polio Day is observed annually on 24 October to raise awareness about poliomyelitis (polio) and the global efforts aimed at its eradication. The day highlights the significance of continued immunisation and the collective actions undertaken to ensure a polio-free world. It serves as a reminder of the success of vaccination programmes and the importance of sustaining progress against this preventable viral disease. The day also commemorates the birth anniversary of Dr Jonas Salk, who led the first team to develop a vaccine against poliomyelitis.

Background and Significance

Polio is a highly infectious viral disease caused by the poliovirus, primarily affecting children under the age of five. The virus invades the nervous system and can cause irreversible paralysis within hours. Transmission occurs through the faecal-oral route or, less commonly, through contaminated food and water. The disease has existed for centuries, but widespread epidemics emerged during the 20th century, especially in regions with inadequate sanitation.
World Polio Day was established by Rotary International to honour the efforts of scientists, health workers, and volunteers involved in the eradication campaign. The observance underscores the importance of global solidarity and sustained funding to eliminate polio completely. Its alignment with Dr Salk’s birth anniversary symbolises humanity’s triumph of science and collective action against infectious diseases.

The Global Polio Eradication Initiative (GPEI)

The Global Polio Eradication Initiative (GPEI) was launched in 1988 as a partnership between national governments, the World Health Organization (WHO), Rotary International, the US Centers for Disease Control and Prevention (CDC), and UNICEF. The Bill & Melinda Gates Foundation later joined as a key partner. Since its inception, GPEI has achieved a dramatic reduction in polio cases worldwide by over 99%.
At the time of GPEI’s formation, polio paralysed more than 350,000 children annually across 125 countries. Due to mass immunisation drives, surveillance, and rapid outbreak response, the number of endemic countries has been reduced to just two—Afghanistan and Pakistan—as of recent years.
Key strategies of the initiative include:

• Routine immunisation to maintain high levels of population immunity.
• Supplementary immunisation activities (SIAs) to reach children missed by routine services.
• Environmental surveillance for poliovirus detection in sewage systems.
• Rapid outbreak response and containment operations to prevent virus transmission.

Types of Polio and Vaccines

There are three serotypes of wild poliovirus: Type 1, Type 2, and Type 3. Wild poliovirus Type 2 was declared eradicated in 2015, and Type 3 in 2019, leaving only Type 1 circulating in limited regions.
Two main types of vaccines are used for immunisation:

• Inactivated Poliovirus Vaccine (IPV) – Developed by Dr Jonas Salk in 1955, IPV uses an inactivated virus and is administered via injection.
• Oral Poliovirus Vaccine (OPV) – Developed by Dr Albert Sabin in the early 1960s, OPV contains a live attenuated virus and is administered orally. It is inexpensive and easy to deliver, making it ideal for mass campaigns.

Many countries have transitioned to using IPV exclusively, as it eliminates the rare risk of vaccine-derived poliovirus (VDPV) associated with OPV. However, OPV remains vital in areas where polio transmission persists due to its ability to induce intestinal immunity.

Progress and Challenges

The near-eradication of polio is one of the greatest achievements in global public health. More than 18 million people who would otherwise have been paralysed are walking today because of vaccination efforts. Over 1.5 billion children have been immunised in campaigns involving millions of volunteers worldwide.
Despite this progress, challenges persist:

• Conflict and Insecurity: Ongoing violence in regions of Afghanistan and Pakistan hampers access to children.
• Misinformation and Vaccine Hesitancy: False beliefs and rumours about vaccine safety discourage participation in immunisation drives.
• Operational and Logistical Barriers: Difficult terrains, migration, and inadequate infrastructure impede vaccination efforts.
• Vaccine-derived Poliovirus (VDPV): In areas with low immunisation coverage, mutated strains of the attenuated virus in OPV can circulate and cause outbreaks.

To address these challenges, the introduction of novel oral poliovirus vaccine type 2 (nOPV2) aims to provide better genetic stability and lower the risk of reversion to virulence.

Role of Organisations and Governments

Rotary International remains a driving force behind World Polio Day and the global eradication movement. Its “End Polio Now” campaign has raised more than US$2.1 billion and mobilised millions of volunteers. Governments and international organisations continue to contribute through surveillance, immunisation campaigns, and policy frameworks.
The WHO, UNICEF, and Gavi, the Vaccine Alliance, collaborate with national ministries of health to ensure vaccine delivery and monitoring. Surveillance laboratories worldwide test thousands of stool and environmental samples annually to detect poliovirus circulation.

Global Impact and Future Prospects

The eradication of polio would mark only the second time in history that a human disease has been eradicated, following smallpox in 1980. The economic benefits are substantial, with projections estimating savings of up to US$50 billion by 2035 due to the cessation of polio vaccination and treatment costs.
Countries certified polio-free, such as India (since 2014) and Nigeria (since 2020), stand as testaments to the feasibility of eradication through sustained commitment and community mobilisation. Lessons learned from polio eradication have also strengthened health systems and improved responses to other infectious diseases, including measles and COVID-19.