CNN  — 

Three years ago, Joshua Nerius, a 30-year-old software product manager in Chicago, developed a high fever and a rash. Doctors prescribed antibiotics, but Nerius just got sicker and sicker.

Joshua went to the emergency room, where a doctor said it looked a lot like the measles. Had he been vaccinated as a child?

Nerius texted the question to his mother. She sent back a thumbs-down emoji.

His next stop was an isolation room at Northwestern Memorial Hospital.

Nerius became so weak that at one point, he couldn’t walk without assistance. He lost 25 pounds. It took months to fully recover.

“I felt horrible,” he said. “It took a serious toll.”

He thinks about the current measles outbreak, which started in Washington state, where dozens of children have suffered because their parents chose not to vaccinate them.

He knows that their suffering – and his own three years ago – could have been avoided.

“It makes me so angry. My parents thought they were doing the right thing. They were persuaded by the anti-vaxers,” he said.

Measles kills

Nerius is something of a unicorn: a living adult who experienced measles recently and can describe what it feels like.

It’s easy to forget how sick people get from measles or how it killed 400 to 500 people in the United States each year before the vaccine came into use in 1963, according to the US Centers for Disease Control and Prevention.

“Measles is out of sight and out of mind, so we think it’s no big deal, as Bill Shine’s wife has said,” said Dr. Paul Offit, director of the Vaccine Education Center at the Children’s Hospital of Philadelphia.