I had ALL the usual childhood illness as a child...german measles, red measles, mumps, chicken pox...I also received the small pox vaccine and polio immunizations. Dad was military and traveled world wide. His family was required to be uptodate all the time.
Fast forward a bunch of years and now Sageofages is a mom...
Daughter # 1 has had the chicken pox THREE times. She had all her regular immunizations except for the CP shot. She now has Crohn's disease and must avoid everyone with a communicable illness and her immune system is considered very compromised.
Everyone around must get the flu shot etc. Grandson had to stay away for 7 days after getting his immunizations to protect her.
Daughter #2 had chicken pox twice. Once at about 6 months and then again around 3. Her immunizations caused no difficulty otherwise.
Sons all have had Chicken pox. One broke out two saturdays before Christmas, and the other two broke out right on schedule 10 days later

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Son #3 did get the red measles from the shot. Caused a HUGE stink with our local health department, especially when my husband broke out with them at the right incubation period later. The Health Dept was in a dither over it. Dr said "yes it is the measles." when the health dept wanted to shush it up. I guess fed money depends on them not having cases. Made me crazy.
My boss had a daughter die from complications of vaccines, so every time the kids/grandson gets their immunizations I am on pins and needles for the first few days.
All in all it is worth the risk.