It's the worst year for measles since the disease was declared eliminated in the US in 2000.

George Frey / Getty Images

Measles, an extremely contagious and potentially dangerous disease, continues to spread in the US, with more than 700 cases so far this year in outbreaks that public health officials say are driven by communities refusing vaccines based on misinformation and conspiracies. Across the country, local leaders have struggled to gain the upper hand against new measles infections — now the worst in decades — and which experts believe will become a new normal. Lawmakers in several states are considering who should be exempt from vaccine mandates: Should religious or personal belief exemptions be allowed in addition to medical ones? Should debunked fears that vaccines cause autism result in medical exemptions?

With this in mind, BuzzFeed News asked each 2020 presidential candidate to lay out their stance on vaccines. We asked: What do you believe about vaccines?

Do you believe vaccines are a possible cause of autism?

Do you support efforts to end religious and personal belief exemptions, leaving only medical exemptions? Eleven Democrats provided answers to BuzzFeed News, describing vaccines as necessary, but taking different approaches to exemptions. Others have supported vaccines but have not publicly spoken about who should be able to refuse immunity — a topic that's prompted heated debate and protests in some communities as low vaccination rates have put more people at risk of infection. On the Republican side, the White House pointed to recent comments made by President Trump supporting vaccination, though he's previously spread false claims about their danger.

President Donald Trump Saul Loeb / AFP / Getty Images

Trump addressed the measles outbreaks for the first time last week while speaking to reporters outside the White House. "They have to get the shots," he said. "The vaccinations are so important.”

That's a departure from what he's said about vaccines for years on Twitter. In dozens of tweets, Trump has said vaccines cause autism — which multiple studies have shown is not true. "Healthy young child goes to doctor, gets pumped with massive shot of many vaccines, doesn't feel good and changes - AUTISM," he said in 2014. "Many such cases!" Trump also promoted the idea of spacing out vaccines, suggesting it could be safer. But the Centers for Disease Control and Prevention have also warned parents against deviating from their vaccine schedule; it leaves young children exposed to some diseases at an age when they're particularly vulnerable. During his transition, Trump sought to create a vaccine safety panel led by Robert F. Kennedy Jr., a prominent vaccine skeptic. That never happened, and Trump hasn't since publicly repeated his prior claims that vaccines cause autism.

Joe Biden Jeff Swensen / Getty Images

The former vice president did not respond to questions. Biden has been an advocate for medical research, however, and has promoted the use of vaccines against cancer. "I look forward to the day when your grandchildren and my grandchildren and their children show up at the office to get their physical to start school and get a shot for measles and they get a vaccine that affects significant causes of cancer," he said while discussing the Cancer Moonshot coalition in 2016. In particular, the Biden Cancer Initiative promotes the HPV vaccine for all boys and girls by age 12 to prevent cancer.

Sen. Bernie Sanders Mark Makela / Getty Images

"Bernie believes that vaccinations work and are crucial to overall public health. Instances of serious but preventable diseases have been significantly reduced and many have been eliminated altogether as a result of vaccines," a Sanders spokesperson told BuzzFeed News. Vaccines go through rigorous clinical trials as well as oversight by the Food and Drug Administration, and there isn't evidence they cause autism, the campaign added. Exemptions should be rare. "Bernie believes opting out can create deadly risks for children suffering from illnesses who may not be able to receive a vaccination and are then exposed to children who are not vaccinated. Any exemptions should be rare and consistent with public health needs," the spokesperson said.

Sen. Kamala Harris Ethan Miller / Getty Images

A spokesperson for Harris kept it simple: "She thinks people should get vaccines." The California senator declined to answer additional questions.

Mayor Pete Buttigieg Spencer Platt / Getty Images

"The law of the land for more than a century has been that states may enforce mandatory vaccination for public safety to prevent the spread of a dangerous disease. Pete does support some exceptions, except during a public health emergency to prevent an outbreak," a spokesperson for the South Bend, Indiana, mayor told BuzzFeed News. In particular, Buttigieg believes exemptions are appropriate for people who can't be vaccinated for medical reasons. Personal belief and religious exemptions should only be allowed in states that aren't facing a public health crisis and where herd immunity rates of vaccination are maintained. "These exemptions include medical exemptions in all cases (as in cases where it is unsafe for the individual to get vaccinated), and personal/religious exemptions if states can maintain local herd immunity and there is no public health crisis," the spokesperson said.

After this article was published, the campaign added in a "clarifying statement" early Wednesday that Buttigieg only supported medical exemptions to vaccinations. "Pete believes vaccines are safe and effective and are necessary to maintaining public health," the spokesperson said. "There is no evidence that vaccines are unsafe, and he believes children should be immunized to protect their health. He is aware that in most states the law provides for some kinds of exemptions. He believes only medical exemptions should be allowed."



Sen. Elizabeth Warren Ethan Miller / Getty Images

The Massachusetts senator responded after publication, saying she supported ending religious and personal exemptions. "The more we do on the front end to ensure that everyone gets access to vaccines, the less we'll see individuals contracting hepatitis A, measles, whooping cough, and all of the other vaccine-preventable diseases. We must make sure there is robust public health funding so people have access to vaccines," Warren said. "Medical data proves vaccines are not linked to autism, that they are safe, effective, and our best chance of protecting people from diseases. I support efforts to end religious and personal belief exemptions and believe that we must have real standards for what constitutes a medical exemption."



Beto O'Rourke Stephen Lam / Getty Images

A campaign spokesperson provided O'Rourke's views on vaccines after publication, but he did not respond to questions on autism or exemptions.



"The evidence is clear and there is wide agreement among doctors and scientists that vaccination is the best course for our kids and our communities," he said. "Beto and Amy have chosen to vaccinate their three children because they believe it is important to ensuring our country’s children are healthy, safe, and secure." Bills related to vaccines and exemptions have regularly come up in O'Rourke's home state of Texas, and during his 2018 run for Senate, anti-vaccine group Texans for Vaccine Choice confronted him on whether he believed parents should be able to opt out of vaccinating their children.

"I know just about as much as any parent. All three of my kids are vaccinated," O'Rourke said in a video posted by the group. "I know that this is an issue that some people have a difference of opinion on. I’m not as informed as I should be to give you a thoughtful answer."

Sen. Cory Booker Scott Olson / Getty Images

"First and foremost, vaccines are proven to reduce the incidence of terrible disease. Vaccines keep people safe and healthy. We need to trust the scientists who work to develop vaccines and the medical professionals who administer them," the New Jersey senator told BuzzFeed News in a statement. Booker added that there is no scientific link between vaccines and autism. "We should limit the number of exemptions from vaccinations to a small number of medical circumstances," he said.

Sen. Amy Klobuchar Ethan Miller / Getty Images

The Minnesota senator did not respond to questions. In April, she signed onto a Senate resolution on the importance of vaccinations. The resolution noted the scientific consensus that vaccines are effective and safe, and that communities with low vaccination rates present a public health risk.

Andrew Yang Alex Wong / Getty Images

"I believe the science. Numerous studies indicate no connection between vaccines and autism," Yang told BuzzFeed News. Yang, an entrepreneur from New York, added he supported California's standard for vaccination, which requires children attending school or daycare to be vaccinated unless they have a medical exemption.

Julián Castro Ethan Miller / Getty Images

Castro, the former secretary of Housing and Urban Development under then-president Barack Obama, did not respond to questions.

John Hickenlooper Zach Gibson / Getty Images

Hickenlooper did not respond to questions. But while Colorado's governor, he was faced with the lowest immunization rates in the country. “Kids that can be vaccinated should be vaccinated,” Hickenlooper told the Colorado Independent in 2015. “There are these urban myths — and in many cases these are now suburban myths and rural myths — that somehow vaccinations increase the probability of autism or other unnamed maladies. But there is no science to support this. The science clearly states that having more and more people unvaccinated puts other children at risk.”

Hickenlooper released multiple public service announcements while in office, but critics questioned whether he did enough. Colorado allows religious and philosophical exemptions from vaccines as well as exemptions for medical reasons.

Sen. Kirsten Gillibrand Mandel Ngan / AFP / Getty Images

"Vaccines save lives. Not only do they provide individual protection, but they protect vulnerable populations, including young children, pregnant women, and people with underlying health issues," Gillibrand told BuzzFeed News. "Simply put, they are essential to protecting public health." The New York senator added that research has shown no correlation between vaccines and autism and called for more education to counter misinformation about vaccine safety. She did not detail her position on exemptions.

John Delaney Don Emmert / AFP / Getty Images

"I think they are necessary," the former US representative from Maryland told BuzzFeed News in a statement. Delaney added that he doesn't believe vaccines are a cause of autism, and that exemptions should be considered based on the nature of particular diseases. For a highly contagious disease like measles, only medical exemptions should be permitted.

Gov. Jay Inslee Mario Tama / Getty Images

The Washington governor responded after publication, calling out anti-vaccine information as dangerous. "I believe in science — and the science on vaccines is crystal clear: vaccinations are safe and protect public health," Inslee said. "Anti-vax misinformation is a danger to public health, as we've seen with the Southwest Washington measles outbreak this year."

The legislature in his home state recently passed a bill to end personal belief exemptions to vaccines, which he is expected to sign into law. Washington continues to allow religious and medical exemptions. "That's why we took action in Washington state," he said, "I'm proud to support a new bill that removes personal exemptions to the MMR vaccine."



Rep. Tulsi Gabbard Eric Baradat / AFP / Getty Images

The Hawaii representative did not respond to questions.

Rep. Seth Moulton Scott Eisen / Getty Images

"Vaccines have saved more lives than almost any other advancement in the history of mankind," Moulton told BuzzFeed News. "They’re the reason we no longer die from smallpox or lose our legs to polio." The Massachusetts representative blamed the current measles outbreaks on the anti-vaccine movement as well as the kind of skepticism exhibited by President Trump. To counter it, he called for tying federal education funds to stricter vaccine compliance — allowing only medical exemptions — while also providing vaccines to all Americans at a low or no cost. "Measles are bad. Vaccines are good. Those truths, for lack of a better term, are self-evident. Not vaccinating kids is dangerous for them and a public health risk for everyone," he said. "Trump might not understand that, but the vast majority of the American people do."

Rep. Tim Ryan Zach Gibson / Getty Images

"I believe mandatory immunizations and vaccinations are critical to keeping our families, our kids, and our communities safe," said Ohio Rep. Tim Ryan. Ryan told BuzzFeed News he does not believe vaccines cause autism, and he supports ending religious and personal belief exemptions.

Rep. Eric Swalwell Joe Raedle / Getty Images

"The recent measles outbreak is a completely avoidable crisis that puts the health of the public, particularly children, at risk," the California representative told BuzzFeed News. "Rather than lead our nation out of this crisis, President Trump, who has previously peddled unfounded theories on vaccines, has instead dedicated his time toward tweeting his grievances with the Mueller report, the media, and his political opponents."

Swalwell said he does not believe vaccines cause autism, and he supports ending religious and personal belief exemptions. "Nobody's beliefs should put other people's lives at risk," he said.

Bill Weld Daniela Kirsch / Sipa USA via AP