Thailand Strengthens Polio Prevention with SIAs in Tak Province Border Districts

The Ministry of Public Health (MOPH) of Thailand, in collaboration with the Tak Provincial Health Office (PHO), the World Health Organization (WHO), the United Nations Children's Fund (UNICEF), and the National Health Security Office (NHSO), has completed two successful rounds of polio Supplementary Immunization Activities (SIAs) in five border districts of Tak province to reduce the risk of poliovirus importation.

The WHO South‑East Asia Region has remained poliofree since its certification in 2014. However, ongoing poliovirus transmission in some parts of the world continues to pose a threat to countries experiencing significant crossborder mobility. Thailand maintains high national coverage of OPV and IPV, but localized immunity gaps persist in border areas due to frequent population movement and vaccine hesitancy.

In early 2025, a circulating vaccine‑derived poliovirus type 1 (cVDPV1) case in the Lao People’s Democratic Republic (Lao PDR) and continued disruption of immunization services in Myanmar prompted intensified AFP surveillance and targeted SIAs in highrisk border provinces.

Tak province, which shares a 533 kilometre border with Myanmar and experiences heavy daily cross‑border movement, was prioritized for action. A total of 300 000 doses of bOPV were mobilized to protect Thai and migrant children in five border districts.

Two SIA rounds were conducted on 11 December 2025 and 13 January 2026 across Thai schools, migrant learning centers, temporary shelters for displaced persons from Myanmar and migrant communities, with strong support from Thai and migrant village health volunteers.

• Round 1 coverage: 97.6% (22 484/23 023) Thai children under 5 years and 96.2% (55 171/57 336) migrant children under 15 years.
• Round 2 coverage: 98.02% (22 636/23 093) Thai children under 5 years and 95.57% (55 778/58 363) migrant children under 15 years.

“These campaigns show what is possible when government, partners, and communities unite to protect children’s health,” said officials from the Tak Provincial Health Office. “Our collective efforts are essential to mitigate the risk of poliovirus importation and safeguard Thailand’s polio‑free status.”

The SIAs were made possible through strong leadership from Tak PHO, close coordination with local authorities, and active engagement from community organizations, NGOs, and teachers.

Thailand remains firmly committed to global polio eradication and will continue strengthening surveillance, routine immunization, and targeted vaccination in high‑risk areas.

For more information, please contact Ms. Aree Mounsgookjarean (National Professional Officer) at setharegistry@who.int.