Foreign interference in Europe is not limited to politics but also extends to health, particularly through the spread of misinformation about vaccines. This has fueled distrust in vaccination programs and weakened public confidence in public health measures. As a result, diseases like measles, which had been largely controlled through widespread immunization, are making a comeback. According to the European Centre for Disease Prevention and Control (ECDC), 2,339 cases of measles were reported in Europe in one year, with nearly 75% of those infected being unvaccinated. To prevent measles from spreading permanently, at least 95% of the population must be vaccinated with two doses. In 2023, only four countries in the European free trade area met this threshold for the second dose, and Belgium, which had 96% coverage for the first dose, only reached 82% for the second. The resurgence of measles is due to multiple factors, including limited access to healthcare for vulnerable groups, outdated vaccination reminders, missed opportunities for immunization, and deliberate refusal to vaccinate. Anti-vaccine sentiment has persisted even after the Covid-19 pandemic, and disinformation has played a major role in deepening these issues. A 2025 study published in the journal Human Vaccines & Immunotherapeutics highlighted that distrust generated during the pandemic has extended to routine childhood vaccinations, increasing the risk of outbreaks of diseases such as measles, diphtheria, and polio. In several Central and Eastern European countries, authorities have pointed to foreign influence in the spread of anti-vaccine messages. In Bulgaria, during a measles outbreak in March 2026, the then Minister of Health Mihail Okoloyski emphasized combating vaccine misinformation as a priority. The Bulgarian public health network reported increased activity from anti-vaccine groups on social media, which sought to undermine official health efforts. Disinformation does not create distrust from scratch but can amplify existing doubts. In 2023, the European Observatory of Digital Media (EDMO) noted the growing presence of Children's Health Defense, an organization founded by Robert Kennedy Jr., which had established a legal structure in Belgium and organized events to promote its anti-vaccine narratives. In October 2025, the movement "Make Europe Healthy Again," inspired by the American slogan "Make America Healthy Again," was launched in the European Parliament with the support of the far-right group Patriots for Europe. In Western European countries, populist parties have used the pandemic and vaccination policies to gain political support, as noted in a 2025 study published in the journal Vaccine. In Austria, far-right and populist parties have focused on anti-vaccine rhetoric, with Herbert Kickl, leader of the far-right FPÖ party, identifying himself as a "vaccine skeptic." In Belgium, the anti-vaccine movement remains relatively small, but the country is not free from vaccine hesitancy. In 2024, Belgium saw its largest measles outbreak since 2011, with 526 cases, mainly affecting unvaccinated children. Even in regions with high vaccination rates, disinformation has raised doubts. To address this, the European Medicines Agency has formed an advisory group to study vaccine hesitancy and provide recommendations to strengthen trust in vaccines. The JITSUVAX project, funded by the EU, has focused on understanding the concerns of those who refuse vaccination, helping healthcare professionals better respond to anti-vaccine arguments.