You’d think that between the two major-party candidates for president, plus the two third-party candidates drawing significant support in the polls, there would be at least one person with an unblemished record of support for mandatory public vaccination ― one of the greatest public health achievements in history ― against the bogus idea that vaccines cause autism.

You’d be wrong. While Republican nominee Donald Trump is the only proponent of the autism theory among those four, each of the other candidates has flirted with it at one point or another. The Huffington Post has rated their vaccine views on a booster shot scale:

Alissa Scheller/The Huffington Post

We award Donald Trump zero out of five possible Booster Shots .

Alissa Scheller

The Republican nominee is a full-blown proponent of the notion that vaccines cause autism, a theory that researchers have studied and rejected over and over after a medical journal helped launch the notion with a 1998 article since retracted.

Lots of autism and vaccine response. Stop these massive doses immediately. Go back to single, spread out shots! What do we have to lose. — Donald J. Trump (@realDonaldTrump) October 22, 2012

I am being proven right about massive vaccinations—the doctors lied. Save our children & their future. — Donald J. Trump (@realDonaldTrump) September 3, 2014

“Autism has become an epidemic,” Trump said during a Republican primary debate last fall, referring to the rise in the incidence of autism in recent decades. He then relayed the story of an unidentified employee whose child, he said, “went to have the vaccine and came back and a week later got a tremendous fever, got very, very sick, now is autistic.”

Trump said that he is “totally in favor” of vaccines but that he wants “smaller doses over a longer period of time.”

Delaying vaccine doses for small children is not a safe choice, as the Centers for Disease Control and Prevention has explained on its website: “Some vaccine-preventable diseases remain common in the United States, and children may be exposed to these diseases during the time they are not protected by vaccines, placing them at risk for a serious case of the disease that might cause hospitalization or death.”

Most of the measles cases in the U.S. since 2000, when the disease was officially found to have been eliminated from this country, have been among people who weren’t vaccinated, according to the CDC.

In 2011, then-Rep. Michele Bachmann tanked in the Republican presidential primary after suggesting an unfounded link between the HPV vaccine and mental retardation. For some reason, pushing risky views about vaccines hasn’t had the same effect on Trump’s candidacy.

Jill Stein gets two Booster Shots.

Alissa Scheller

Stein recently said that she is “not aware” of evidence linking vaccines to autism and that it’s false to call her anti-vax. The Green Party nominee made those comments after people criticized her for suggesting there may be vaccine dangers in a July interview with The Washington Post.

“As a medical doctor, there was a time where I looked very closely at those issues, and not all those issues were completely resolved,” Stein told the Post. “There were concerns among physicians about what the vaccination schedule meant, the toxic substances like mercury which used to be rampant in vaccines. There were real questions that needed to be addressed. I think some of them at least have been addressed. I don’t know if all of them have been addressed.”

Stein’s campaign argued that she wasn’t pandering to anti-vaxxers in that interview and that she was just trying to say Americans have legitimate concerns “that the pharmaceutical industry exerts undue influence in our regulatory institutions.”

Several public health experts said Stein’s remarks still amounted to throwing shade on vaccination. “My definition of anti-vaccine is that you put out information about vaccines that’s misleading, that you put out bad information,” Paul Offit, director of the Vaccine Education Center in Philadelphia, told Salon. “She’s done that.”

Gary Johnson gets three Booster Shots.

Alissa Scheller

He tweeted in 2011 “no to mandatory vaccines,” but the Libertarian Party nominee came around this August in an interview with NPR.

“You know, since I’ve said that … I’ve come to find out that without mandatory vaccines, the vaccines that would in fact be issued would not be effective,” he said. “So … it’s dependent that you have mandatory vaccines so that every child is immune. Otherwise, not all children will be immune even though they receive a vaccine.”

Hillary Clinton gets four Booster Shots .

Alissa Scheller

In 2015, Clinton made a forceful statement in favor of mandatory vaccination, saying on Twitter “the science is clear” that vaccines are good. She sent the tweet in the aftermath of a measles outbreak that had prompted less reassuring statements from other politicians.

The Democratic nominee’s only demerit is a statement on a 2008 questionnaire that expressed uncertainty about the autism claim, contrary to the medical establishment.

“We don’t know what, if any, kind of link there is between vaccines and autism ― but we should find out,” Clinton wrote. Then-Sen. Barack Obama also said more research needed to be done.