The Centers for Disease Control and Prevention (CDC) reported that between January 1 and May 23 of this year, there were 288 cases of measles reported in the US. That’s more than the total number of cases in any year since 2000, when measles was eliminated in the U.S..

We have got to get more people immunized.

Essentially all of the cases were linked to “importations,” cases brought in from other countries were measles is common. Most of the cases were in people who weren’t immunized. Of the 195 U.S. residents who caught measles and weren’t immunized, 85% chose not to be immunized — as opposed to being too young or having a medical reason that prevented getting the vaccine.

It got me thinking about the families I see who choose not to immunize their children. While I think that vaccines are a great idea and have immunized my children, I respect every family’s right to make the medical decisions that they think best for their children. And while I think that the recommended vaccine schedule is safe, I am always willing to work with families if they really want to do something different. Better to have some vaccinations, or vaccinations on a different schedule, than none at all.

But when I read about the resurgence of vaccine-preventable diseases like measles, polio or pertussis, I worry — and wish that there wasn’t so much fear about vaccines. Here are the most common reasons I hear for refusing or delaying vaccines:

1. These illnesses are rare. This one is so interesting, because it’s actually a testament to the effectiveness of vaccines. Many illnesses are rare purely because of vaccines. And when lots of people are vaccinated, it protects those who can’t be or choose not to be vaccinated. We have a name for that: “herd immunity.” But that herd immunity can break down when more people start choosing not to vaccinate — and in our global society, illnesses like measles or polio are just a plane ride away. Even if you or your friends don’t travel, you just can’t know where the family next to you in the elevator or waiting room or food court has been.

2. These illnesses aren’t all that bad. I hear this one often in comments on blogs I write about immunizations. It’s certainly true of many vaccine-preventable illnesses that they aren’t always serious (except perhaps for illnesses like meningococcemia — that’s pretty much always bad). But they all have the possibility of being serious. Measles, for example, can lead to many complications, including brain complications, and can be fatal. Of the U.S. cases this year, 43 were hospitalized, five got pneumonia and three had other complications. Many have died in the measles outbreak in the Philippines. The risk of getting really sick from the disease is always going to be higher than the risk of getting really sick from the vaccine. That’s an important point that sometimes gets lost in the discussion. The other point that often gets lost is that while you or your child might weather chicken pox or measles or whatever just fine, if the newborn next door or your ailing grandmother catches it from you, they might not. Vaccines affect the health of entire communities. I wish it were just a personal decision, but it’s not.

3. Vaccines cause autism. I really, really wish that we knew what causes autism. It is heartbreaking to work with the families of autistic children and not be able to give them an explanation. And when they have a new baby, it’s truly terrifying to be on the journey with them, staring at that child, wondering what, if anything, we should do differently. But we’ve looked at this, again and again, and we just can’t find any solid evidence to show that vaccines cause autism. For more details and information about this, check out the latest report from the Institute of Medicine.

4. Vaccines have side effects. Yes, they do. But that’s true of any and all medical treatments; vaccines are no different and no worse. Most of the time, the side effects are mild and go away quickly. Sometimes, rarely, they are more serious — and what’s hard is that we can’t really predict who will have the more serious side effects. But as I said, that’s true of every medication, every surgery, every procedure, everything we do. It’s important to look carefully at the numbers when it comes to side effects, as serious ones truly are rare. You can find more information at the website of the Vaccine Adverse Effects Reporting System.

5. The preservatives in vaccines are dangerous. I used to hear this only about thimerosal — which was likely never dangerous in the first place, but is no longer in any of the vaccines we give routinely to young children (the flu vaccine has thimerosal-free formulations). Now I’m hearing it about other things that are added to vaccines to make them safe and make sure they work. I hear it about aluminum, which is added to make some vaccines more effective — but babies get more exposure to aluminum in breast milk or formula than they do in vaccines. Lots of what is put in vaccines is found in other medications or in foods. So while it’s totally appropriate to want to know everything that’s in a vaccine (for more information on additives, with a link to a list of all the additives in each vaccine, check out this fact sheet), please talk to your doctor and ask questions before you refuse a vaccine because of one of them.

6. It’s a conspiracy — the pharmaceutical companies and government are keeping secrets from us.  This one puzzles me. Not that I trust every single person that works for a pharmaceutical company or the government, but the conspiracy would also have to include lots of researchers, doctors, nurses and other health workers — who don’t stand to gain in any meaningful way from vaccines. Also, the number of people who would have to be sworn to secrecy, and be amazingly good liars and equally good at creating fake data, well, it’s mind-boggling. And impossible.

7. I trust my family, friends and community more than my doctor. This one makes me really sad. Clearly, my colleagues and I need to do a better job of building trust and communicating. The whole purpose of our job is to get and keep people healthy. If people don’t believe that, or don’t think we can be clear-thinking advocates for them, then we need to do some real soul-searching — and some real talking with people about how we can better help and serve them.

We are at a crossroads: International travel and lower vaccination rates are coming together to make those diseases we wiped out come back. Please, let’s find a way to have some productive, thoughtful conversations, conversations in which both sides are heard, before more people get sick.

Remember, it’s the young, the old and those that are already sick that are most likely to get into trouble from vaccine-preventable diseases. They need us to take care of them.

Claire McCarthy is a pediatrician at Boston Children’s Hospital. She blogs at the Huffington Post, where this article originally appeared, and at Boston.com as MD Mama.