When I was a child, my mother deliberately exposed me to other children who had it, in an attempt to have me get the illness, and then be immune to it. I didn't get it.
Since then, I have been directly caring for at least 7 different people who had chickenpox, and I didn't get it. Working in the healthcare industry for over 22 years, I had multiple employers test me to see if I had developed antibodies to the virus, and I had not. So, they insisted that I get the vaccine.
I have had the vaccine no fewer than 5 times in my life. I still do not develop antibodies, and I still have never caught the illness. What do doctors say about this?
Adults who have no demonstrable VZV antibodies after 3 doses of vaccine must be presumed to remain susceptible to varicella. There are no data on vaccination with more than 3 doses.Now, I know why there is no data. The reason for this is that fewer than 1 in 100,000 adults fail to seroconvert after 3 doses. There is just no money to be made in doing a study of such a small population. The reason that I bring this up is to remind everyone that there is much that we we don't know about our universe, and unless there is money to be made or some other compelling reason, we likely will never investigate it.
The good news here for me means that I will likely never have shingles, either.