As very simply written on the Center for Disease Control’s (CDC) website, “Young babies can get very ill from vaccine-preventable diseases.”

Many readers probably already know about the source of the conspiracy that vaccines are dangerous or can cause autism: Andrew Wakefield’s study from 1998, based on only 12 patients, which was based on falsified data that suggested a link between vaccinations and autism. His medical license was subsequently stripped, but the idea has continued to stay in the spotlight for a variety of reasons.

Of course, parents must be cautious with their children’s health. Any research that suggests that they are putting their kids at risk is likely to make them hesitate. It’s human nature, it’s understandable. However, another large component is the inexplicable celebrity support that the movement has had over the past two decades. Jim Carrey, for one, is extremely anti-vaccine—or, in his words, “anti-thimerosal” (a mercury-containing compound that is in flu shots to prevent contamination). The information is out there. Everyone should know better by now. 

We don’t have to think about the consequences of actually getting the diseases that the vaccinations prevent anymore, making vaccines seem less and less necessary. Know why? The fact that the vast majority of the U.S. population has been receiving these vaccines for decades has led to widespread eradication of what they prevent. Smallpox is completely gone: We don’t even give the vaccine anymore because the only known existing samples of it are kept in laboratories for various reasons. (Namely, to make an antidote in the case of an outbreak, which is certainly possible considering that, in 2014, samples of smallpox were found in a store room in Maryland that had been entirely forgotten about.)

It’s easy to forget, but measles is dangerous. It’s so easy to forget because we’ve fixed this problem. We developed a vaccine. But, in 2014, 667 people in the United States contracted the measles. It is often likened to chicken pox and made to seem less serious than it really is. 1 in 20 children who contract the measles will also develop pneumonia, 1 in 10 will get ear infections, and 1 in 1000 will develop encephalitis, a swelling of the brain that can lead to permanent intellectual disability. As reported by the Center for Disease Control (CDC), most people that contracted it were unvaccinated; however, some had gotten the vaccine. Many point to this as a reason to not vaccinate their children, because it may not work anyway. Although I am sympathetic to parents not wanting to put their children at risk, not vaccinating kids is a selfish act.

Here are the facts: For the immunity of individuals, we need herd immunity. Herd immunity is the concept that a single unvaccinated individual can take down an entire community if they become infected. It is impossible to test that the effectiveness of a vaccine because of course we can’t test the effectiveness of a vaccine. How would we? By exposing children to the disease?

Let’s answer this easy question: What usually happens when you get a vaccine? You’re protected from the disease. That’s it. Actual real risks to getting vaccinated include swelling at the site of injection. In extremely rare cases, a severe allergic reaction can occur, but that is the most dramatic (and unlikely) reaction. 

Vaccines are safe. Please know that. For your safety, for the safety of your family, and for the safety of those in your community, get vaccinated. I understand that you may not want to personally take a risk. It’s not a risk. Do it anyway.

There is no link between autism and vaccines. To quote Sean Spicer, “Period.”

Now, as everything must, here’s where it gets political.

On March 28, 2014, Donald Trump tweeted: “Healthy young child goes to doctor, gets pumped with massive shot of many vaccines, doesn’t feel good and changes – AUTISM. Many such cases!”

Now, we all know that just because an idea is comes out of his mouth—or, more often, his small, Twitter-hungry fingers—it won’t necessarily be acted on. And this was three years ago. His perspective has probably switched by now, or at least he’s forgotten about the whole issue. Right?

On Jan. 10, 2017, Trump met with Robert F. Kennedy, Jr., who is outspoken in his opposition to vaccines. An NPR article on the meeting reported that Trump was considering forming a committee to research autism, which is, in his mind, apparently still linked to being vaccinated. So this is yet another bizarre example of Trump maintaining views that are entirely based in falsehood.

Unfortunately, this is a debunked theory that seems to be sticking: According to a 2015 study, nearly 1 in 10 Americans believe that there is a link between vaccines and autism, but there is no reason to give any legitimacy to this “argument.” So, if you need another reason to mistrust President Donald Trump and where he gets his information, look at his views on vaccines.

Reale is a member of the Class of 2020.