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

Their skepticism helped shape policy — the Covid vaccine mandate never happened. And it led to greater caution. More parents started scrutinizing 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 percent in 2024, and the vaccine for polio reached 99 percent.

“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.