I don't think your car seat analogy is a very good one. Vaccines have risks and side effects, unlike car seats.
I never said that the vaccine has a higher mortality rate than chicken pox. In fact I said the exact opposite. However, I did say that they are "comparable".
I agree that pneumococcus and meningococcus are frightening bacteria. However, as you point out, they exist commonly out in the world. So how come everyone isn't succumbing to these? Apparently, some people have stronger immune systems than others. Rather than injecting people with rather toxic substances (see more below) to prepare their bodies to fend off an attack, it would seem preferable to strengthen their immune systems, with organic fruits & vegetables, physical activity, sunlight, clean water, clean air, etc.
Before injecting one's children with a vaccine, two questions need to be asked:
1. Is it safe?
2. Is it effective?
I want to be able to confidently answer "yes" to both questions before I'll give a vaccine to my daughter. Currently, I answer both questions with "not sure".
First, are vaccines safe? Vaccines contain a number of potentially harmful substances. Mercury has gotten the most bad press in recent years, and it has finally been removed from most vaccines. Many vaccines contain human & animal tissues. Yes, they are screened, however, there remains the potential for tiny infectious agents (prions, or whatever) to pass through. Aluminum is added to a number of vaccines. Aluminum is well-known to cause neurologic harm. Has anyone determined a safe level of injected aluminum? As far as I can tell, the answer is "no". Formaldehyde, used as a preservative in many vaccines, is a known carcinogen. And MSG is used in some vaccines. It can damage nerve tissue. Vaccines can have both short-term and long-term side effects. The short-term side effects are better understood. Quite commonly, vaccines cause vomiting, diarrhea, headaches, rashes, etc. More rarely, they may cause Guillain-Barre syndrome, encephalitis, SIDS, paralysis, and vision problems. The long-term side effects may include autism, ADHD, learning disorders, and autoimmune diseases (all of which seem more prevalent now than they did 20 years ago, perhaps due to the increased number of vaccinations given today).
Second, are vaccines effective? The number of diagnoses of many diseases fell rapidly following the introduction of the corresponding vaccine. Vaccine proponents credit the vaccine, of course. Vaccine opponents often credit improvements in public sanitation, hygiene, & nutrition, along with the "expectation bias". The expectation bias basically says that doctors are less likely to diagnose a disease when they know that the vaccine has been given. The way to really prove that vaccines work is to have double-blind placebo-controlled studies. However, these studies are never done. Why not? Well, for one thing, the studies are always funded by the vaccine manufacturers, and so the expectation bias is working in their favor, and so there is no reason for them to eliminate it. Because the proper studies have never been done, I think the jury is still out as to vaccine's effectiveness.
Finally, let's address the issue of social responsibility. Unvaccinated kids benefit from so-called "herd immunity" (the protection of all the vaccinated kids around them) without risking taking the vaccines themselves. Is this selfish? Perhaps. Are you supposed to make decisions that are good for the country as a whole? Or do you base your decision on what's best for your own child as an individual? I think we all put our children first in most situations.
I like to think of it this way. If you choose to vaccinate your children, you are actively taking a risk. If one of your kids suffered a bad side effect, it would be because of something you did. If, on the other hand, you don't vaccinate, you are taking a passive risk. You would be taking the chance that a disease would not happen to your kids. You are leaving it up to nature, or chance, or God. In this case, if they become ill, it won't be because of something you did, but rather something you didn't do. I personally find that type of guilt easier to live with.