With regard to the chicken pox vaccine, I understand what you are saying in terms of chicken pox generally being a mild disease. But it still causes ~150 deaths per year in the US and costs $1B to US society due to hospitalization and lost productivity (see links below). These deaths are of previously healthy individuals unlike deaths from influenza which kills immuno-compromised individuals. From briefly searching, it appears that the cost of the vaccination program is on par with the hospitalization cost of the disease. This means that the benefit of the vaccine is due to decreased societal costs due to lost productivity, i.e. parents staying home with sick kids. From a societal point of view, this is a very reasonable reason to create a vaccine. http://www.cbc.ca/health/story/2005/02/02/chicken-pox-050102.html http://www.wrongdiagnosis.com/artic/facts_about_chickenpox_varicella_cdc_oc.htm The question about shingles after vaccination is interesting. Pre-vaccine, the vast majority of individuals contracted chicken pox, so I'm guessing the incidence rate for shingles will be equivalent before and after the vaccine was introduced. It will be interesting to see how the severity of shingles for vaccinated individuals compares to that for unvaccinated individuals. I have seen quotes saying that it is less severe for those who had the vaccine. I think this is disingenuous since the vaccine has only been around for 15 years and we already know that shingles is less severe in younger individuals. It will take another 30-40 years to determine what happens with the severity of shingles. With regard to many vaccines at the same time, it is my belief (based only on the data of my two children) that for healthy children this is not a problem at all, but for immuno-compromised individuals it could be an issue.