Colombia has activated a yellow fever alert after registering 11 human cases and 10 deaths in the first weeks of the year, all among unvaccinated people. The country is now ordering targeted booster shots and urging citizens not to delay vaccination in endemic and high‑risk areas.
Since 2024 yellow fever has claimed more than 70 lives in Colombia, with official reports indicating 73 deaths and 154 confirmed cases by late January 2026, mostly in rural and forested zones. For a tropical country where Aedes aegypti and other vectors are present year‑round, lapses in immunization quickly translate into serious outbreaks.
Yellow fever egional outbreak and Colombia’s current situation
The recent surge is not isolated. The World Health Organization has documented renewed yellow fever activity across the Americas, including non‑Amazon regions in Brazil and areas such as Tolima in Colombia, where eco‑epidemiological conditions favour transmission. This broader context explains why Colombian authorities stress that the virus “has not gone away” and that vaccination must remain a routine protective measure.
In Colombia, 2026 began with 11 laboratory‑confirmed human cases and 10 deaths, all in people who had never been vaccinated against yellow fever. At the same time, health surveillance has recorded 78 epizootics (animal version of an epidemic) in non‑human primates between 2025 and January 2026, mainly in Tolima, Huila and Putumayo, clear signs of active viral circulation in ecosystems shared with nearby communities.
Worth noting is that Tolima now concentrates the highest number of cases and deaths, prompting intensified vaccination, vector control and risk communication in municipalities such as Cunday, Villarrica, Purificación, Prado, Chaparral, Ataco and Planadas. These territories, with warm climates and fragmented forests, represent the type of high‑risk environment described in recent outbreak analyses for the region.
Booster strategy and who should receive an extra dose
In response, Colombia issued External Circular 001 of 2026, which unifies criteria for yellow fever booster doses and clarifies that a single shot still offers lifelong protection for most people. The directive focuses on specific groups whose risk profile or immunological situation justifies an extra dose in the current emergency.
Booster vaccination is now recommended for people vaccinated more than 10 years ago who live in, or plan to travel to, municipalities with active viral circulation, especially in Tolima. It also applies, after individual risk‑benefit assessment, to people with HIV with CD4 counts above 200 cells/mm³, recipients of hematopoietic stem‑cell transplants, laboratory staff handling wild‑type virus and women vaccinated during pregnancy, who should receive a booster six months after giving birth.
The Ministry of Health of Colombia convened the National Immunization Practices Committee on 21 January 2026 to support these recommendations, underlining that decisions are grounded in scientific evidence and international guidance. Colombia has already administered nearly 5 million yellow fever vaccine doses between September 2024 and January 2026, yet persistent gaps in adult coverage continue to drive severe cases.
Vaccination, travel and the long‑term challenge for Colombia
Colombia does not generally require yellow fever vaccination to enter the country, except for travellers arriving from certain endemic nations, but it strongly recommends immunization at least 10 days before visiting risk zones and national parks in the Amazon, Orinoquía, Magdalena basin and other endemic corridors. For residents of affected departments, health posts offer the vaccine free of charge in hundreds of authorised points nationwide.
Health authorities insist that the yellow fever vaccine is safe and highly effective, granting protection in about 95% of people ten days after administration and approaching 99% after 30 days. They warn that refusing vaccination, particularly during an active outbreak, exposes individuals and their communities to a preventable and potentially lethal disease.
Experts highlight that Colombia’s real test lies in sustaining high coverage among adults in rural, jungle and border areas, where access barriers, misinformation and distrust often intersect. The truth is, controlling yellow fever in the country will depend not only on emergency circulars, but on a long‑term, community‑centred strategy that improves surveillance, risk communication and equitable access to vaccines for every Colombian living in, or travelling to, high‑risk territories.