The Rise of Measles: A Global Concern, Fueled by Anti-Vax Sentiment
In a worrying development, Latin American countries are ramping up their vaccination efforts to combat a surge in measles cases, a direct consequence of the outbreaks in North America. This year has seen a staggering 34-fold increase in measles cases across the region, prompting urgent action from governments.
Measles, a highly contagious disease, has made a global comeback, reaching a 25-year high. The primary drivers of this resurgence are low vaccine coverage and the spread of misinformation about vaccine safety. However, the situation in Latin America is further complicated by unequal access to healthcare and the alarming trends in the US, which is experiencing its worst measles outbreak in decades.
"The US's stance on health and vaccination is a scandalous failure," asserts Dr. Rosana Richtmann, an infectious disease specialist and coordinator of the Brazilian Society of Infectious Diseases' immunisation committee. "It's a problem that affects us all."
Measles was successfully eradicated from the Americas in 2016 and again in 2024, but the continent now faces the risk of losing its measles-free status. The latest data from the Pan-American Health Organization (PAHO) reports 11,668 cases across 10 countries in North and Latin America. More than half of these cases are concentrated in the US and Canada, with a tragic toll of five deaths so far.
Mexico bears the brunt of the outbreak in Latin America, with over 4,800 cases and 22 deaths, followed by Bolivia with 354 cases. Other countries, including Brazil, Belize, and Paraguay, are managing smaller outbreaks linked to imported cases.
The high number of cases in North America has prompted the Brazilian health ministry to prioritize a nationwide vaccination campaign targeting children and teenagers, launched in October. The campaign also offers the measles, mumps, and rubella (MMR) vaccine to adults who missed it during childhood.
Brazil's swift response to individual cases is commendable. When a nine-year-old tested positive for measles in Várzea Grande, health authorities sprang into action. Nurses, equipped with protective gear, visited the child's school and implemented "ring vaccination," inoculating everyone who had been in contact with the child. The city's health teams have also been conducting door-to-door campaigns to identify unvaccinated individuals and hosting vaccination drives at a shopping center and the international airport.
Dr. Richtmann expressed her greatest concern about imported cases. "We're more worried about Brazilians traveling to Europe, the US, or Canada [and bringing measles back] than about those who live here," she said.
Amira Roess, a professor of global health and epidemiology at George Mason University, Virginia, agrees that the outbreaks in the US pose a threat to neighboring countries. "Now, you're more likely to encounter someone with an infectious disease [in the US]. You visit the US, you go home with souvenirs—and you might also go home with measles," she warns.
Mexico's first measles case in February was imported from Texas by an unvaccinated Mennonite boy. Similarly, Bolivia's initial cases spread through pockets of unvaccinated people living in Mennonite settlements.
Mennonites, Anabaptist Christian communities of European descent, reject many aspects of modern life, including vaccines.
Daniel Salas, executive manager of PAHO's special program for comprehensive immunisation, highlights the challenges posed by close-knit communities resistant to vaccination and the large flows of people across the region. "Having close-knit communities that are often reluctant to receive vaccinations and having large flows [of people] from country to country through the region are aggravating factors," he said.
Health authorities must identify and target these resistant communities, Salas emphasized.
Measles, a disease with no cure, can lead to serious complications and even death. However, it is easily preventable with two doses of the MMR vaccine, which provides 97% protection. MMR vaccination rates in Latin America suffered during the Covid pandemic and the preceding years, but they have recovered since 2022, reaching 86% last year, according to the World Bank. Despite this improvement, the region still falls short of the 95% threshold needed for herd immunity, with a lag in the uptake of second doses and significant disparities between and within countries.
Lack of information and access to healthcare have contributed to lower vaccination rates, but doctors also attribute this to the growing influence of the anti-vaxxer movement in the US.
"A lot of South American countries look to the US," said Carlos Paz, head of infectious diseases at the Mario Ortiz Suárez paediatric hospital in Santa Cruz, Bolivia, where 80% of the country's cases have been reported. "The population sees what a US minister says about vaccines, and some people start to say, 'well, we shouldn't get vaccinated here either.'"
While the US health secretary did endorse the MMR vaccine after an outbreak in Texas in April, Kennedy has also spread misleading information about the vaccine and misinformation about measles treatment.
This month, the US Centers for Disease Control and Prevention, now led by a biotech investor, suggested that the MMR vaccine should be given as three separate jabs, despite decades of research demonstrating the safety and efficacy of combined shots and going against the CDC's own longstanding advice.
Bolivia declared a national health emergency in June, extended school holidays to reduce contact between children, and launched a widespread vaccination drive, relying partly on donations from Brazil, India, and Chile. However, coverage in October remained low at 45%, while the government still has 1.6 million doses available.
"We've been campaigning to increase the vaccination rate. Each doctor, each pediatrician, is a soldier advocating for vaccination," said Paz.
But here's where it gets controversial: Should we solely blame the anti-vax movement for this global health crisis? Or is there more to this story? What are your thoughts on the role of misinformation and its impact on public health? Feel free to share your opinions and insights in the comments below!
