An urgent need to vaccinate: Bolivia’s response to the ongoing measles outbreak in isolated communities

The outbreak that raised the alarm

As of March 2026, Bolivia continues to respond to the outbreak, amid a broader resurgence of measles across the Americas. Although transmission has decreased in some areas, in communities with limited access to health services or incomplete vaccination schedules, there is still considerable risk.

In the Region, cases increased significantly in 2025, with nearly 15,000 confirmed across 13 countries, and almost the same number reported in the first three months of 2026. Most cases are among people who are unvaccinated or whose vaccination status is unknown, confirming that low vaccination coverage remains the main risk factor.

In Bolivia, the outbreak began in Santa Cruz in April 2025 and gradually spread, leading to the declaration of a national emergency. To date, more than 600 cases have been reported in the country.

The scale of the outbreak called for a comprehensive response. Bolivia stepped up vaccination among children aged 1 to 4 with two doses of the measles, mumps, and Rubella vaccine (MMR) and expanded coverage to those aged 5 to 20 through mass vaccination efforts. More than one million doses have been administered nationwide through the Expanded Program on Immunization. 

With technical support from the Pan American Health Organization (PAHO) and funding from the Government of Canada, Bolivia strengthened surveillance, outbreak control, and its ability for a rapid response. Mobile brigades were deployed in cities, rural and Indigenous communities, and peri-urban areas, while schools and public spaces were used as vaccination sites.

The campaign continues, with an emphasis on finding active cases, strengthening epidemiological surveillance, and closing immunization gaps.

Vaccinating where time stood still

There are more than 150 Mennonite colonies in Bolivia, mainly in Santa Cruz. In addition to geographic isolation, language and cultural barriers, these communities are also reluctant to vaccines.

“We are in a colony where time seems to have stood still,” explains José Elver Martínez, director of the Pailón Health Center. “Here, a disease we had not seen in more than 20 years has returned—and it came back strong.”

Health brigades coordinated vaccination efforts through the colonies’ ministers, who provide religious leadership, and community leaders within each colony. A first barrier was language: many people speak only Low German. The response was to incorporate local translators and community leaders as allies.

To reach people, trust must be built. “Nothing works if you don’t speak with their leaders,” says Martínez.

The nurse who built the bridge

Elena Friesen de Brown, a Canadian nurse who lives in the Hohenau colony, played a key role during this process. With experience working in a hospital first in Paraguay and then in Bolivia, Elena understands both the urgency of the response and vaccine hesitation in the community. 

“In nearly every colony, the unvaccinated adults and children had measles,” she recalls. Alarmed by the rise in cases, she sought out vaccines and became a bridge between Bolivia’s health system and the colonies.

“We have always lived without vaccines,” says Ana Baumann, a Mennonite woman, through an interpreter. “But now we decided to get vaccinated. There were too many sick people. We need everyone to be healthy.”

Thanks to the hard work, most Mennonite families in these communities now accept vaccines, maybe not every family, but enough to break the chain of transmission.

A nationwide challenge

Outside of the Mennonite colonies, the challenges take different forms. In urban areas, vaccine misinformation has complicated the response, requiring communication efforts to reach families. The National Vaccination Registry has helped identify children with incomplete vaccination schedules, revealing persistent gaps. Coverage for the MMR vaccine—both first and second doses—remains below the recommended 95% needed to prevent outbreaks, leaving pockets of susceptibility in the population.

In rural Indigenous areas, distance and poverty required local brigades to go door to door, coordinating with community leaders and schools to ensure vaccines reach the right people.

Today, in Isidro Blatz’s home, the situation is different. Everyone is vaccinated—his children, his neighbors, most of the colony. The outbreak has left hard lessons: measles can return, but it can also be stopped.

For the health sector, there are additional lessons: the fight is never over, and collective action can make a difference. The challenge continues to reach isolated, rural pockets, increase vaccination coverage, and above all, build trust. With technical support from PAHO/WHO and the Government of Canada, Bolivia is proving that a coordinated response, community outreach, and communication are key to confront a virus that once seemed to be in retreat.