Something you might consider, unrelated to the vaccine safety issue, is that your family might be genetically more susceptible to those diseases, so even with vaccination, your immune systems weren't able to prevent infection.
It's possible that the additional immunity theoretically provided by vaccination saved your lives, by proactively preparing your less effective immune systems against the diseases.
The only answer for having the diseases after being vaccinated for them ISN'T that the vaccines were ineffective.
As @theaustrianguy points out, different people have different genetics, and our immune systems are different as a result.
This is also something, returning to vaccine safety, that makes giving everybody the same vaccine risky. Some people will be harmed by things that others, even everybody else, isn't.
Before very recently, it would have been impossible to differentiate between people whose genetics and immune systems require different medical treatment.
Thankfully, personalized medicine is being developed, and soon, perhaps these risks will be a thing of the past.
Setting big hopes in this aspect as well!
@valued-customer: I have two explanations for the reasons why my siblings and I did get sick. First of all: my mother didn't breastfeed either of us. She grew up in a very Catholic part of the Netherlands and I think with my brother (who's sixteen years older than me) they would have told her that it was not done to breastfeed. When my sister was born, my mother was a single parent with no support, so she had to leave my sister in care with nuns. When I was born, the midwife somehow told her some crap about how I didn't want her milk because I kept spitting (turns out: her supply was too much for my greedy little self) and talked her into giving up. So that may be a very important factor in the story. I do have to say that neither one of us is ever really sick besides a little flu or cold every few years. My sister and brother would have kept up with their vaccines, I have never had anything after I left the home at 19. I don't really believe us getting sick had much to do with our immune system, because the whole story about genetics that's been given by the medical profession is questionably as well, but of course, it's always a possibility. I am not a medical professional (not in the traditional sense anyway) but I did study pathology and anatomy during my study as a hypnotherapist. Besides this, I've been studying about different areas in the field as well during my research missions. So even though I really don't know everything, I did learn that this subject is definitely not as black and white as both sides think it is. Thank you for your input @valued-customer, you just gave me something new to work on and think about. Your input is always valuable 😎
At least you did receive some colostrum from your mother, which is chock full of antibodies and many immunoresponsive factors. Breastfeeding is extraordinarily important to immune system function in children, and perhaps throughout life.
It is certain that amongst the most important breastmilk is the very first few days, as that is when the initial immune system assets are primarily passed to infants.
You are clearly applying sound thinking to the questions, and I am sure you are better informed than I ever could be about your medical situation.