The increase in the number of measles cases registered in the United States, Mexico and Canada – which will host games at the 2026 World Cup – raises awareness of the need to vaccinate Brazilian tourists who will travel to these countries. Together, the three account for 70% of cases in the Americas. The observation was made this Tuesday (9) to Agência Brasil by infectious disease specialist Natalie Del Vecchio, from the National Institute of Women's, Children's and Adolescent's Health Fernandes Figueira, from the Oswaldo Cruz Foundation (IFF/Fiocruz). Related news: Campaign against measles aims to prevent imported cases during the World Cup. Opas: "We have already eliminated measles from the Americas and we can do it again." Ministry of Health warns of risk of measles cases after World Cup. “Measles is a highly contagious disease,” he said. This means that one person with the virus can transmit it to many others simultaneously. “And we have seen low vaccination coverage in these countries and also in Brazil”, observed Natalie Del Vecchio. Expansion Last year, the World Health Organization (WHO) warned of the expansion of cases, when Canada registered 5,062 occurrences, which led to the loss of certification as a country free of the disease. In 2026, 124 cases were confirmed in Canadian territory. Mexico increased the number of seven cases, reported in 2024, to 6,152 records in 2025. In January of this year alone, there were 1,190 cases, according to preliminary information. In the United States, in turn, there were 2,144 cases in 2025 and 721 in January 2026. According to the infectious disease specialist at IFF/Fiocruz, the danger is greater for Brazilians who travel to these countries without having a complete measles vaccination schedule. Vaccination can prevent the eventual reintroduction of the virus in Brazil. Natalie recalled that, in November 2024, Brazil received recertification as a measles-free country from the Pan American Health Organization (PAHO). The document was delivered to President Luiz Inácio Lula da Silva and the then Minister of Health, Nísia Trindade. In 2016, Brazil had already achieved this position as a nation free from the endemic circulation of measles, but in 2018, low vaccination coverage allowed the reintroduction of the virus in the country. Risk “Low vaccination coverage is a risk for our country of reintroduction of the virus in Brazil”, stated the infectious disease specialist. In 2025, 38 cases were reported in the country, all imported from neighboring nations. In January 2026, two cases of measles were recorded in a 22-year-old woman. in Rio de Janeiro, and a 6-month-old baby in São Paulo. The two had no vaccination record. Natalie Del Vecchio recommends that even people who are not going to travel to the World Cup host countries should try to complete their vaccination schedule. For those over 1 year of age and up to 30 years of age, two doses of the measles vaccine are required and, from 30 to 60 years of age, one dose. "If the person already has their calendar complete, they do not need to take an extra dose of the vaccine. If the calendar is not complete, travelers heading to the World Cup host countries must complete the vaccination schedule. These people will travel with peace of mind, precisely so that they are not acquiring the measles virus, nor bringing it to our country. To, precisely, avoid a new outbreak and new cases of measles in Brazil", said the infectious disease specialist. Reinforcement The Ministry of Health launched a national campaign advising Brazilians who will travel to the United States, Mexico and Canada for the World Cup to reinforce their measles vaccination. For children aged 6 to 11 months, the recommendation is that they take the zero dose at least 15 days before traveling. In the range of 12 months to 29 years, it is necessary to have two doses. Adults aged 30 to 59 must have received at least one dose throughout their lives. Another recommendation is that the MMR vaccine (which also protects against mumps and rubella) should be administered at least 15 days before traveling. The doses are available free of charge in health units of the Unified Health System (SUS). Gravity Measles is a serious disease that can leave lifelong consequences and even cause death. The main complications vary according to the patient's stages of life. For children, it can cause pneumonia, ear infections, acute encephalitis (inflammation in the brain – part of the nervous system inside the skull) and death. In adults, it causes pneumonia. And, in pregnant women, it can result in premature birth and low birth weight babies. Highly contagious, the disease spreads through coughing, talking or breathing. An infected person can infect others before they even know they are sick. The most common symptoms are high fever, persistent cough, runny nose, eye irritation, and red spots that start on the face and then on the body. Symptoms usually appear between seven and 14 days after contact with the virus.