US anti-vaccine policies ripple across the world

When Vietnam considered making Covid-19 vaccines mandatory for children deep into the pandemic, many parents resisted, fearing side effects and rumors of expired doses.

Their scepticism helped shape policy — the Covid vaccine mandate never happened. And it led to greater caution. More parents started scrutinising packaging to ensure that every vaccine jabbed into an arm came from a reputable company.

What Vietnam’s Covid concerns did not do was metastasize into a broader anti-vaccine movement like what the world is now watching in the United States. Instead, Covid revived gratitude for routine vaccination. Coverage for the first dose of the measles vaccine in Vietnam reached 98% in 2024, and the vaccine for polio reached 99%.

“There was a scare, and that’s why there was an almost global commitment to say, ‘We will now work toward making a more robust system,’” said Basil Rodrigues, UNICEF’s Regional Health Adviser for East Asia and the Pacific. “Countries are trying to ensure that they strengthen their vaccine systems.”

Brazil, Nigeria, Hungary and Samoa are just a few of the nations investing more in vaccination to try to catch up after COVID, during a global rise in outbreaks of measles and yellow fever.

That makes the United States an obvious outlier, though not because of public opinion, which still favors vaccination. Rather, experts say, it is because of the government. Health Secretary Robert F Kennedy Jr and other vaccine critics are now in charge of public health and — under a banner of MAHA or “make America healthy again” — they are stripping away support for vaccine development, promotion and distribution.

Florida recently became the first US state to announce an end to mandates for vaccines. Experts say that weakens a policy devised to ensure that — in a decentralized and unequal health care system — nearly every child could be protected from horrific infections.

Kennedy has defunded vaccine research. He has replaced vaccine experts with critics on a key advisory panel, limited access to Covid-19 shots and muddied official guidance on many others, worrying experts who see confusion eroding vaccine confidence worldwide.

As Heidi J. Larson, who leads the Vaccine Confidence Project at the London School of Hygiene and Tropical Medicine, recently put it in an essay for The Lancet: “The US, long a cornerstone of global health leadership, has become an unexpected source of global instability in vaccination confidence.”

The Department of Health and Human Services, responding to such critiques from experts, said in an email that Kennedy was simply “being honest and straightforward about what we know — and what we don’t know — about medical products, including vaccines.”

But scientists see facts being cast aside, with effects that could last for years.

“The threat is this: that the US style anti-vax movement linked to MAHA wellness-influencer grifting and authoritarianism is now globalising,” said Peter J Hotez, a vaccine expert at Baylor College of Medicine and the author of a new book, The Deadly Rise of Anti-Science. 

Doubts Are Common. So Are Mandates.

Americans are not unique in having doubts about vaccines, not now and not before COVID.

During French rule in Vietnam, medicines, including vaccinations, were seen as tools of colonization. They were rumored to be used for sterilizing women and girls, fears that also arose elsewhere, including in parts of Africa and among Indigenous groups in Canada.

Decades later, the CIA’s deployment of a fake hepatitis B vaccination program to locate Osama bin Laden in Pakistan significantly damaged trust.

In China, many still resist vaccination after one of the country’s main vaccine manufacturers falsified inspection and production reports in 2018.

Governments have typically responded to concerns, both valid and unfounded, with outreach and science. Over decades, they have added clinics in remote areas, collaborated with international partners on public service campaigns and relied on doctors to recruit families.

Mandates, usually focused on entry to school, have also been common for decades.

In a recent study of 194 countries by international academics, 106 nations had policies requiring vaccination for at least one disease. Vaccines against diphtheria, measles, and tetanus were the most mandated, while Covid vaccines were among the least.

Enforcement varies. Some countries (48 of the 106) do not let children attend school without certain shots. In others, like Vietnam, which has 11 mandatory vaccinations, schools play a role in checking vaccine coverage and nudging parents to comply.

Mandates are far from the only method of persuasion. In Argentina, the unvaccinated are excluded from getting passports. In Australia, since 2016, only families that immunize their children receive family assistance payments, including subsidized child care.

Then there is Pakistan. In 2023, authorities in the province that includes Karachi threatened to imprison parents for up to a month if they failed to get their children immunized against polio and eight other diseases.

Governments often harden childhood mandates when threats intensify. For example, Italy and France added measles to their mandatory schedules after outbreaks in 2017 and 2018. Within two years, vaccination rates had risen nearly 6 percentage points in Italy, and around 4 in France.

That is usually how it goes, though less so with Americans.

After a measles outbreak in 2015 led California to stop letting parents opt out of vaccines for nonmedical reasons, such as “personal belief,” fewer kindergartners showed up at school without their shots. But studies later found that medical exemptions had quadrupled. The medical exemption rate at private schools was 10 times higher than the median nationwide.

America the Free. America the Sick?

America did not start out determined to avoid vaccines.

In 1806, President Thomas Jefferson wrote a letter to Edward Jenner, an English scientist, thanking him for developing the world’s first vaccine, against smallpox. Jefferson wrote that he “took an early part in recommending it to my countrymen.”

In 1855, after a rash of smallpox deaths, Massachusetts became the first state to require that children be vaccinated for school. In 1905, the Supreme Court upheld the right to mandate vaccination for public safety.

None of that history earned a mention when Joseph Ladapo, the Florida surgeon general, announced last week that Florida would end vaccine mandates.

“Who am I to tell you what to put in your body?” he said to loud applause, at an event near Tampa. “Your body is a gift from God.”

Ladapo and others — including Kennedy — have celebrated a “your research, your choice” approach that, according to various studies, bolsters false claims of vaccine danger. Worldwide, the U.S. is a major exporter of vaccine misinformation.

But infectious diseases move along vectors of logic. And Americans are not immune.

Between 2018 and 2023, the Americas, including the United States, reported nearly 50,000 confirmed cases of measles in 18 countries, according to the World Health Organization. Between December 2024 and April 2025, there were 212 confirmed cases of yellow fever in the region, including 85 deaths, triple the number of cases from 2024.

Many of the outbreaks had been imported from other countries, with cases coming from as far away as Thailand.

That global exchange of vaccine-preventable diseases will become more common, experts argue, because worldwide vaccination levels are still below those from before COVID — the pandemic disrupted the supply chain for many vaccines and kept people from scheduled vaccination. It is also, many add, because the U.S. government is backing away from the country’s role as a champion of immunization.

“It’s a cliché that infectious diseases know no borders, but it is true that our global preparedness and response to infectious diseases relies on a strong US presence and US commitment to vaccination, from research to development to deployment,” said Jason L Schwartz, a public health professor at Yale. “So the steady weakening of US government support for all aspects of vaccination will invariably weaken our response to vaccine preventable diseases around the world.”

What makes the current moment especially disconcerting for those who see vaccines as the saviors they were when they first appeared is that senior US officials are validating a view that often treats vaccines as a contaminant.

Over the years, Covid vaccines have elicited a similar sentiment from some other leaders — Jair Bolsonaro of Brazil, President John Magufuli of Tanzania, Aleksandr Lukashenko of Belarus. But officials in their countries still stressed that vaccination was generally safe.

Experts say that the US retreat from vaccination is more unusual. Never before has a country as large, educated, rich and influential as the United States put the weight of government behind an argument focused on vaccine harm.

“Governments tend to promote and support vaccination as a public health good,” said Samantha Vanderslott, a vaccine expert at Oxford University.

“What is happening in the US right now,” she added, “is starkly different.”

Maybe Vietnam and a few others with vaccination rates above 95% will have enough immunity to avoid the fallout. But in many countries, a small dip in vaccination could create huge vulnerabilities.

Vaccine veterans such as Rodrigues, who has spent 40 years at UNICEF, worry about countries like Papua New Guinea, where the reemergence of polio a few years ago required six rounds of vaccination and many millions of dollars to control.

In May, another outbreak emerged with two infected children. As of mid-August, polio had spread to at least 31 people, setting off alarms around the Pacific.

“If anyone is unprotected,” Rodrigues said, “there’s a risk to everyone.”