KVIG Informative

Measles was declared eliminated from the United States in 2000. In 2025, it surged across North America. Canada lost its elimination status. The U.S. may follow in 2026. Vaccine exemptions are at a record high. The public health infrastructure that would respond is being dismantled. None of this is a surprise to the people who study it.

In 2000, the Centers for Disease Control declared measles eliminated from the United States — meaning the disease was no longer spreading continuously within the country. That status, achieved through decades of sustained vaccination campaigns, represented one of the clearest victories in the history of American public health. In 2025, measles surged across North America. Canada lost its measles elimination status in November, with case counts at levels not seen in decades. The United States is projected to follow in 2026.

The resurgence is not the result of a new variant or a vaccine failure. The vaccines work. The problem is that fewer people are getting them. Vaccine coverage in U.S. kindergartners has declined from approximately 95 percent to 92 percent over the past dozen years. Exemptions from one or more recommended vaccines reached a record high of 3.6 percent in the 2024-25 school year, according to the CDC. At the population level, 95 percent coverage is the threshold required to maintain herd immunity against measles. The U.S. is now below it.

Why Measles Specifically

Measles is among the most contagious diseases ever documented. One infected person can transmit the virus to 12 to 18 others in a susceptible population. For comparison, seasonal flu transmits to roughly 1.3 people. COVID-19’s original variant transmitted to approximately 2 to 3. The reason measles was the target of elimination campaigns — rather than simply suppression — is precisely because its contagiousness means that once community coverage drops below the herd immunity threshold, the virus does not slowly return. It comes back fast.

The consequences of infection are also more severe than many people remember. Before widespread vaccination, measles killed approximately 2.6 million people globally per year. In children under five, it remains one of the leading causes of preventable death worldwide. Even in previously healthy children in wealthy countries, measles can cause encephalitis, permanent hearing loss, and a condition called subacute sclerosing panencephalitis — a fatal brain disease that can develop years after the initial infection.

The Infrastructure Problem

The resurgence of measles in 2025 is occurring against a backdrop of deliberate weakening of the public health infrastructure that would normally respond to it. Robert F. Kennedy Jr., appointed to lead the Department of Health and Human Services in 2025, has a documented history of promoting vaccine skepticism. His department oversees the CDC, the FDA, and the NIH — the agencies responsible for vaccine policy, safety monitoring, and outbreak response.

Whooping cough — pertussis — is also rising alongside measles. Both diseases were effectively controlled in the United States for generations through vaccination programs that are now being undermined by the same combination of declining coverage and political pressure on public health institutions. Epidemiologist William Moss at the Johns Hopkins Bloomberg School of Public Health said there have been enormous changes in 2025, driven by the current administration and their attitude towards both foreign aid and domestic vaccine policy.

What History Tells Us

In 1989 and 1990, a measles outbreak in the United States infected more than 55,000 people and killed 123 — most of them children. The outbreak occurred after years of declining vaccination coverage and was concentrated in cities with large unvaccinated populations. The response required a national vaccination campaign, changes to school immunization requirements, and years of sustained public health effort to restore elimination status.

Over the past 50 years, immunization programs have saved an estimated 154 million lives globally. That number represents the accumulated effect of exactly the kind of sustained, politically unglamorous public health infrastructure now being questioned, defunded, and in some cases actively undermined. The science did not change. The political will did. And the disease is coming back to show exactly what that costs.

Measles does not care about policy debates. It spreads through the air. It infects the unvaccinated. It is entirely preventable. And it is back.