Last month, a 6-week old baby in Florida died from whooping cough. The death was completely preventable and is a tragic illustration of just how important childhood vaccines are–to all of us.

The baby himself was too young to have been immunized, but because babies are so vulnerable, everyone around him should have been. Someone, however, wasn’t. The family’s philosophy on chidhood vaccines isn’t known, so let’s give them the benefit of the doubt and assume that whoever wasn’t up to date on his or her immunizations simply made a mistake and had no idea there was a problem. In a way, though, that makes this death even more heart-rending. Here’s why:

Over the years I’ve occasionally argued with other parents about childhood vaccines and whether kids should get them or not. Often, the arguments revolve around purported connections between immunizations and autism (which have been thoroughly debunked), the possibility of contracting the disease that the vaccine is supposed to prevent (nearly impossible, given that most—if not all—childhood vaccines are made from dead viruses, not the live ones that were used in the past), or the risks of having a dangerous, negative reaction to the vaccine (which does happen, but incredibly rarely).

While I try to respect others’ opinions, the facts are pretty straightforward. If you don’t want to vaccinate your child, okay. But understand that the only reason why your un-vaccinated child is alive at all is because my children—and the majority of others like them—are. If my kids weren’t immunized, they could transmit a potentially deadly disease to any un-immunized children (which is exactly what happened in Florida), who would, in turn, transmit it to still more un-immunized kids. But the children whose shots are up to date would be protected themselves and, perhaps even more importantly, they would be protecting others (which is exactly what should have happened in Florida).

If enough parents make the choice to opt out of child vaccines, we’ll end up with epidemics that could kill thousands–the kinds of epidemics and pandemics that vaccines have been preventing for quite some time. Bottom line: childhood vaccines are safe and they save lives. What else is more important than that?