The Social Security (CCSS) has launched a free yellow fever vaccination campaign on Wednesday.

Yellow fever is a viral disease caused by the yellow fever virus, a Flaviviridae RNA virus transmitted through the bite of an infected mosquito. Common symptoms include fever, chills, loss of appetite, nausea, muscle pain (particularly in the back) and headaches.

Most infected people recover within five days. However, severe cases can lead to abdominal pain, liver damage, jaundice, an increased risk of bleeding and kidney complications.

The vaccination campaign is being carried out at public cantonal clinics, locally known as Ebais.

The vaccine is available to Costa Rican citizens and foreign residents who plan to travel to Colombia before Feb. 28 and who have confirmed airline tickets.

 

Appointments are required and must be scheduled through the CCSS website. Applicants must complete an online form and select a preferred appointment date.

Health officials said temporary website slowdowns or outages are due to high demand and encouraged travelers to check back frequently, as additional appointment slots may become available.

Authorities warned that the yellow fever vaccine is contraindicated for certain groups. These include infants younger than 6 to 8 months, adults older than 60, pregnant or breastfeeding women, people with severe immunosuppression (including those with symptomatic HIV) and individuals allergic to vaccine components.

In May 2025, the Costa Rican government began requiring all travelers departing the country for Colombia, including residents and tourists, to present proof of yellow fever vaccination.

According to Colombia’s Ministry of Health, the country has reported more than 150 yellow fever cases and 63 deaths so far this year.

Costa Rican health authorities, however, reported no active yellow fever cases in the country as of Thursday.

In October, officials confirmed Costa Rica’s first yellow fever case in nearly 70 years. The patient was a 29-year-old U.S. woman who entered the country after traveling from Peru. She had not been vaccinated.

In 2025, the Pan American Health Organization issued an epidemiological alert for the Americas following an increase in confirmed human cases and a shift in the disease’s geographic distribution across several countries.

The CCSS is the state-run institution responsible for managing Costa Rica’s public health system.