This is what happens to the body when HIV drugs are stopped for millions of people

A generation has passed since the world saw the peak in AIDS-related deaths. Those deaths — agonizing, from diseases or infections the body might otherwise fight off — sent loved ones into the streets, pressuring governments to act.

The United States eventually did, creating PEPFAR, arguably the most successful foreign aid program in history. HIV, which causes AIDS, is now manageable, though there is still no cure.

Now the Trump administration has put the brakes on foreign aid while alleging it's wasteful, causing chaos in the system that for over 20 years has kept millions of people alive. Confusion over a temporary waiver for PEPFAR — and the difficulty of restarting its work, with U.S. workers, contractors and payments in upheaval — means the clock is ticking for many who are suddenly unable to obtain medications to keep AIDS at bay.

The U.S.-led global response to HIV has been so effective that AIDS wards of people wasting away are a vision of the past. Now health experts, patients and others fear those days could return if the Trump administration doesn’t reverse course or no other global power steps into the void, and fast.

“In the next five years, we could have 6.3 million AIDS-related deaths,” the U.N. AIDS agency told The Associated Press. That's a shock at a time of rising complacency around HIV, declining condom use among some young people and the rise of a medication that some believe could end AIDS for good.

The agency has begun publicly tracking new HIV infections since the aid freeze.

Here’s a look at what happens to the body when HIV drugs are stopped:

An immune system collapse

HIV is spread by bodily fluids such as blood, breast milk or semen. It gradually weakens the body’s immune system and makes it vulnerable to disease, including ones rarely seen in otherwise healthy people. The surprising emergence of such cases in the 1980s is what tipped off health experts to what became known as the AIDS epidemic.

Years of intense advocacy and shocking sights of children, young adults and others dying of pneumonia and other infections led to the response that created PEPFAR, the President’s Emergency Plan for AIDS Relief. Twenty million people around the world died before the program was founded. Now millions of people take drugs known as antiretrovirals that keep HIV from spreading in the body.

Stopping those drugs lets the virus start multiplying in the body again, and it could become drug-resistant. HIV can rebound to detectable levels in people’s blood in just a few weeks, putting sexual partners at risk. Babies born to mothers with HIV can escape infection only if the woman is properly treated during pregnancy or the infant is treated immediately after birth.

If the drugs are not taken, a body is heading toward AIDS, the final stage of infection.

The daily danger of germs

“Without HIV treatment, people with AIDS typically survive about three years,” the Centers for Disease Control and Prevention says.

For a long time, there may be no noticeable symptoms. However a person can easily spread HIV to others, and the immune system becomes vulnerable to what are called opportunistic diseases.

The National Institutes of Health says opportunistic diseases include fungal infections, pneumonia, salmonella and tuberculosis. For a country like South Africa, with the world’s highest number of HIV cases and one of the largest numbers of TB cases, the toll could be immense.

Unchecked by HIV treatment, the damage continues. The immune system is increasingly unable to fight off diseases. Every action, from eating to travel, must consider the potential exposure to germs.

Every day counts

For years, the importance of taking the drugs every day, even at the same time of day, has been emphasized to people with HIV. Now the ability to follow that essential rule has been shaken.

Already, hundreds or thousands of U.S.-funded health partners in countries such as Kenya and Ethiopia have been laid off, causing widespread gaps in HIV testing, messaging, care and support on the continent most helped by PEPFAR. At some African clinics, people with HIV have been turned away.

Restoring the effects caused by the Trump administration's foreign aid freeze during a 90-day review period, and understanding what’s allowed under the waiver for PEPFAR, will take time that health experts say many people don't have.

Meanwhile, the head of the U.N. AIDS agency, Winnie Byanyima, told the AP that more resistant strains of the disease could emerge.

And an additional 3.4 million children could be made orphans — another echo of the time when the world raced to confront AIDS with few tools at hand.