Polio Resurgence: Ireland’s Polio-Free Status at Risk

The global resurgence of polio poses a renewed, though currently limited, risk to Ireland’s polio-free status, according to the Health Protection Surveillance Centre (HPSC). While Ireland has been free of wild poliovirus since 1984 and officially polio-free since 2003, the detection of cases and the virus in environmental samples in other parts of the world raises concerns about potential importation.

Polio is a highly infectious viral disease that primarily affects children under five years of age. The virus targets the nerve cells in the spinal cord and brainstem, which control muscle movement, potentially leading to paralysis or even death. The most significant outbreak in the Republic of Ireland occurred in 1956, with 499 cases reported. However, the introduction of the polio vaccine dramatically reduced the incidence of the disease.

Recent data from 2025 indicates confirmed polio cases in multiple countries, including Afghanistan, Pakistan, Nigeria, Chad, Yemen, Ethiopia, Angola, Benin, Niger, Sudan, Djibouti, and Burkina Faso. The HPSC notes that the presence of the virus in environmental samples – such as wastewater – in these regions is also a cause for concern.

“Ireland has been polio-free for decades, but global resurgence poses a risk,” a spokesperson for the HPSC stated. Preventing the spread of the virus within Ireland relies heavily on maintaining high vaccination coverage and implementing catch-up programs for individuals considered at risk.

Ireland’s vaccination schedule includes the six-in-one vaccine, which provides protection against polio, administered at two, four, and six months of age. An additional dose is given at 13 months for infants born on or after October 1st, 2024. The World Health Organization (WHO) recommends a vaccination uptake target of 95% to ensure herd immunity.

Historically, Ireland achieved high vaccination rates. National uptake for three doses of the six-in-one vaccine increased from 86.4% in 1999 to 95% in 2013, remaining above the WHO target for several years. However, more recent data reveals a concerning trend. Vaccine uptake has declined since 2021, reaching 90.6% in the first quarter of last year. Similarly, uptake of the four-in-one booster vaccine for children aged four to five years has been below the 95% threshold since the 2011/2012 school year, standing at 89.9% in the 2023/2024 school year.

This decline in vaccination rates, while not yet causing outbreaks, underscores the importance of ongoing efforts to promote vaccine confidence and accessibility. The HPSC emphasizes that Ireland has “comprehensive structures and systems in place to support prevention and early detection of polio.” These systems include robust surveillance programs to monitor for any signs of the virus within the country.

Currently, it is estimated that approximately 5,000 polio survivors reside in Ireland, the majority being middle-aged or older. However, Polio Survivors Ireland has also noted an increase in members who have recently immigrated from countries where polio remains endemic, highlighting the potential for imported cases.

The WHO has been actively monitoring the global polio situation, convening the 41st meeting of the Emergency Committee under the International Health Regulations (IHR) on March 6, 2025. The committee reviewed data on both wild poliovirus type 1 (WPV1) and circulating vaccine-derived polioviruses (cVDPV). The report from that meeting indicated a more than four-fold increase in WPV1 cases in Afghanistan and a more than twelve-fold increase in Pakistan between 2023 and 2024. A total of 36 new WPV1 cases were reported in 2025, with 33 originating from Pakistan and three from Afghanistan.

The European Region, while currently polio-free, is not immune to the risk of importation. The WHO European Region retained its polio-free status for 2023, but stresses the need for increased vigilance. The detection of poliovirus in wastewater in several European cities has prompted urgent calls for action to strengthen surveillance and address gaps in immunity.

While the risk to Ireland remains low due to existing vaccination programs and surveillance systems, the global situation serves as a critical reminder of the importance of continued vigilance and maintaining high vaccination rates to protect the population from this debilitating disease. The HPSC continues to monitor the situation closely and will adapt its strategies as needed to safeguard Ireland’s polio-free status.