Last week, House Republicans released their plan to replace Obamacare, giving Americans a sense, at long last, of how their health insurance might change under the Trump administration. Today the Congressional Budget Office followed up with an estimate on what would happen if the law is passed, and its findings were grim: 24 million people would lose their coverage by 2026. That’s much larger than anyone anticipated, and it’ll be devastating for many Americans.

In its report, the CBO outlined another alarming effect on health: If implemented, the GOP’s American Health Care Act would kill the funding that established the Prevention and Public Health Fund, the federal budget’s largest budget allocation for disease prevention, by 2019.

“Funding under current law [Obamacare] is projected to be $1 billion in 2017 and to rise to $2 billion in 2025 and each year thereafter,” the CBO report says. “CBO estimates that eliminating that funding would reduce direct spending by $9 billion over the 2017-2026 period.” This assessment “fails to take into account that these dollars will have to be replaced through the regular appropriations process,” the American Public Health Association pointed out in a statement, calling this a “health policy disaster.”

The ACA established the Prevention and Public Health Fund with a simple mission: to boost public health money, much of it for the US Centers for Disease Control and Prevention (CDC), to support activities that keep people from becoming sick. (At a time when more Americans would be gaining insurance, keeping people healthy and out of the health care system carried extra appeal for lawmakers.)

The Prevention Fund helps kids and their families get the vaccines they need. It supports programs that reduce the risk of heart disease, cancer, and lead poisoning in communities. “It also pays for key elements of the emergency preparedness systems that are in place throughout the nation,” explained John Auerbach, president and CEO of the public health nonprofit the Trust for America’s Health, “including the people who respond quickly when there is a weather disaster, a new infectious disease outbreak like Zika or an elevated number of fatal drug overdoses.”

Over the years, the fund has become a prime target for Republicans, who generally regard public health as paternalistic and have called the program a “slush fund for jungle gyms.” Congress has subjected it to a slew of cuts. So it’s not a surprise that the American Health Care Act plans to sever the fund altogether.

But killing that funding is going to have an outsize impact on many of America’s key public health activities.

It’ll cripple the Section 317 vaccines program, which has been called “the backbone of our nation’s immunization infrastructure.” Section 317 ensures that doctors get the vaccination doses they need, helps people who can’t afford vaccines gain access to them, and mobilizes responses to outbreaks such as measles, among other things. Getting rid of the fund will mean Section 317 would lose half its funding, which is frightening at a time when vaccination rates are already down in some states.

Eighty percent of the funding for evidence-based education and health programs prevent heart disease — the No. 1 cause of death in America — comes from the Prevention and Public Health Fund, so that’ll disappear, too. So will 100 percent of the funding for programs to reduce the risk of health care–associated infections at hospitals.

The CDC will also face a major cut. Over the years, several items in the CDC’s core budget have been shifted over to the fund. With the fund’s disappearance, $890 million (or about 12 percent) of the CDC’s annual budget would be lost.

“Simply put, without the Prevention Fund the American people will be less healthy and some will die unnecessarily,” said Auerbach. The effects here will be a lot more slow-burning and subtle than the immediate tragedy of an individual losing her insurance. But over the long run, they could be just as devastating.