When I was a resident in pediatrics in the 1980's (I know, I'm getting pretty old), I spent a great deal of my time taking care of kids with HiB (a bacterial infection, not to be confused with "the flu", caused by influenza viruses). I saw kids with HiB cellulitis, HiB meningitis, HiB epiglottis, and just plain old HiB sepsis. It's not a pretty disease. The meningitis can cause brain damage and/or hearing loss, and some HiB infections cause the most feared complication: death. I saw so many HiB infections that I wonder what pediatric residents do all day now, since HiB took up a major part of my time.
Okay, class, second question. Do you know why no one in our class has seen HiB disease in the last ten years? Because we developed a vaccine for it that has nearly eradicated the disease from developed countries. It's been great to see; in my career, I've seen a vaccine developed and then stamp out a terrible disease, just like earlier generations of pediatricians saw vaccines wipe out terrible diseases like polio and small pox. When you've seen the scourge of a disease, you're especially grateful for the vaccine.
Maddeningly, there are still some people who are opposed to vaccinations, such as my ex-brother-in-law and Muslin Imams in Nigeria, where polio still kills kids because the Imams say polio vaccine is part of a plot by the U.S. to harm kids. It's crazy. People claim that vaccines are not safe, but that's not really the question. The question is, which is safer, vaccines or taking your chances with the diseases? Unquestionably, the vaccines are. Even if you believe a lot of the malarkey that anti-immunization folks say - most of which is not true - it would still be safer than getting, say, measles, or pertussis (yes, we still see these diseases) and certainly safer then getting HiB disease.
And if you don't believe me, I could probably find you some parents from my residency days who are still grieving their kid's death from HiB.