Polio safety guidance for Thai travellers has been updated. Health authorities now categorize five popular European destinations under Level 2 precautions after poliovirus was detected in wastewater. The message is clear: borders stay open, but travellers should review and update polio vaccination before leaving Thailand, and health systems should bolster immunity checks.
Polio remains a highly contagious disease that can cause permanent paralysis and, in severe cases, death. The current detections involve circulating vaccine-derived poliovirus type 2 (cVDPV2) found through wastewater monitoring in major European cities. Countries affected are ramping up vaccination campaigns and strengthening disease surveillance to prevent transmission. The goal is to reduce travellers’ risk of acquiring or exporting poliovirus and to prompt clinics and immunisation programs to close immunity gaps. Environmental signals are increasingly used as early warnings.
For Thai readers, the implications are twofold. First, many Thais travel to Europe for work, study, and leisure, so pre-travel medical checks and vaccine planning matter more than ever. Second, the situation underscores a global reality: polio can re-emerge through importation or vaccine-derived strains even in regions with strong health systems if pockets of under-immunised people exist. Thailand’s routine vaccination performance will influence its resilience to any importation and serves as a prompt for public-health vigilance and community action, according to guidance from international health authorities.
Key facts and timelines show the pattern. Wastewater monitoring first flagged related vaccine-derived polioviruses in Western Europe in late 2024, with detections later appearing in several countries. Genetic analysis links these isolates to a lineage associated with a cVDPV2 emergence that started in West Africa in 2020. No paralytic polio cases linked to these environmental detections have been confirmed in Europe yet, suggesting limited immediate transmission. However, the viruses’ genetic diversity indicates they circulated undetected for months, illustrating the value of environmental surveillance as an early warning tool.
Public health authorities are acting decisively. The World Health Organization continues to treat global polio as a Public Health Emergency of International Concern (PHEIC) and has extended temporary recommendations to curb international spread. Measures include intensified surveillance, vaccination to close immunity gaps (including targeted vaccination for travellers from affected areas when appropriate), and, where feasible, documentation of vaccination for cross-border travellers. Experts note that cVDPV2 outbreaks are driven by gaps in routine immunisation, displacement, and insecurity, underscoring the need for ongoing international coordination and funding.
Experts emphasise measured, not alarmist, responses. The Level 2 travel notice means travellers should ensure up-to-date polio vaccination and maintain standard hygiene practices. Adults who completed a polio vaccine series as children should consider an IPV booster if plans include travel to areas with circulating poliovirus and have not already had one; those who completed an adult IPV schedule usually do not require extra doses unless advised by clinicians. High routine immunisation coverage and sensitive surveillance remain the core defenses against importation turning into local transmission.
For Thailand, practical takeaways are clear. Thailand has maintained strong childhood vaccination coverage, with data showing solid polio immunisation levels compared with some regions, though gaps can exist among marginalised groups and mobile populations. Routine immunisation, including timely IPV doses where used, remains critical to prevent vulnerability to any importations. Thai health authorities should reinforce routine immunisation checks at schools and clinics, sustain AFP surveillance sensitivity, and consider targeted communication for groups that frequently travel to Europe—students, migrant workers, business travellers, and tourists—about pre-travel vaccination and documentation.
Historical lessons from Southeast Asia highlight the power of vaccination campaigns. The region was certified polio-free for wild poliovirus in 2014 due to robust immunisation efforts. This success rests on cultural strengths—families prioritising child health and respect for official guidance—which can support high uptake of any catch-up or booster campaigns if needed. Reaching hard-to-reach groups, including rural residents and mobile populations, still requires flexible outreach, mobile teams, and trusted community networks, including temples and local leaders.
Looking ahead, scenarios vary. If routine immunity remains high and detections are limited to wastewater with no clinical cases, risk to Thailand remains low and responses can be targeted. If more detections or rare paralytic cases emerge, international and national programmes may implement intensified vaccination drives or targeted boosters for high-risk travellers. Funding gaps for polio eradication could slow rapid responses in lower-income or unstable countries, so continued donor support remains essential.
For clinicians, public-health officials, and travellers, practical steps are clear. Before travel to the named European destinations, check vaccination history with a clinician well in advance (at least four to six weeks prior). If unsure about completing the polio series, consider an IPV booster before travel. Health facilities should keep vaccination documentation up to date and be prepared to issue it if required. Public-health units should monitor AFP reporting and evaluate whether expanding environmental surveillance to major airports or ports is warranted. Schools should ensure children are up to date with routine immunisations and arrange catch-up doses as needed.
Three practical actions for Thailand’s health system emerge: reinforce routine immunisation and ensure timely IPV doses; strengthen surveillance, including prompt AFP reporting and evaluating environmental surveillance pilots at international hubs; deliver clear travel health guidance through hospitals, travel clinics, and embassies that explains booster recommendations and how to obtain them. Engage communities through trusted channels—primary care units, temple-based health volunteers, and school nurses—to reach families at risk of missing vaccination notices.
The CDC advisory and ongoing PHEIC status remind us that polio eradication remains a global effort in progress. Thailand’s strong public-health infrastructure positions it well to prevent local impact, but vigilance remains essential. Families planning travel should treat polio immunisation like any routine travel vaccine: plan early, vaccinate as needed, and maintain documentation. Health officials should use this moment to close remaining immunity gaps, especially among mobile and hard-to-reach groups, upholding the principle that polio is a threat everywhere until eradicated globally.