Thailand strengthens polio prevention through SIAs in border districts of Tak Province

The Ministry of Public Health (MOPH), 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), successfully conducted two rounds of polio Supplementary Immunization Activities (SIAs) in five border districts of Tak Province between December 2025 and January 2026. These activities aimed to reduce the risk of poliovirus importation in areas with high levels of cross‑border population movement.

The WHO South‑East Asia Region has remained polio‑free since its certification in 2014. However, ongoing poliovirus transmission in some parts of the world continues to pose a risk to countries with substantial cross‑border mobility. While Thailand maintains high national coverage with oral polio vaccine (OPV) and inactivated polio vaccine (IPV), localised immunity gaps persist in certain border areas due to frequent population movement and vaccine hesitancy.

In early 2025, the detection of a circulating vaccine‑derived poliovirus type 1 (cVDPV1) case in Lao PDR, together with disruptions to routine immunization services in Myanmar, prompted intensified acute flaccid paralysis (AFP) surveillance and targeted SIAs in high‑risk border provinces.

Tak Province, which shares a 533‑kilometre border with Myanmar and experiences substantial daily cross‑border movement, was prioritised for action. A total of 300 000 doses of bivalent OPV (bOPV) were mobilised to protect both Thai and migrant children across five border districts.

Two SIA rounds were conducted on 11 December 2025 and 13 January 2026, reaching children through Thai schools, migrant learning centres, temporary shelters for displaced persons from Myanmar, and migrant communities. The campaigns were strongly supported by Thai and migrant village health volunteers.

• Round 1 coverage:
  97.6% (22 484/23 023) among Thai children under five years of age
  96.2% (55 171/57 336) among migrant children under 15 years of age.

• Round 2 coverage:
  98.02% (22 636/23 093) among Thai children under five years of age
  95.57% (55 778/58 363) among migrant children under 15 years of age.

“These campaigns demonstrate what can be achieved 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 to safeguard Thailand’s polio‑free status.”

The SIAs were made possible through strong leadership from the Tak PHO, close coordination with local authorities, and active engagement of community organisations, non‑governmental organisations, and teachers.

Photo Credit: WHO/Thailand