I do not think it is harmful to get the shingles vaccine if you have not had chicken pox. I cannot find anything on the CDC website that says that people who have never had chicken pox should not receive shingles vaccine. I think that the difference between shingles vaccine and chickenpox vaccine is the dose—higher in the shingles vaccine because the immune system of older people is not as strong as that in younger people. Also, the immunity from the shingles vaccine only lasts about 5 years.
You can get tested for chicken pox immunity. I was tested recently for chicken pox, rubella, and measles immunity, and I am immune against all three. I had shingles about 4 years ago, and was vaccinated for rubella and measles in the 1980s. Anyway, the kind of blood test you are looking for is a titer test for immunity against chicken pox. They can do titers for the other diseases, to see if you need those vaccinations, as well.
If you have not ever had chicken pox, you will not get shingles. But you can still get chicken pox, which puts you at risk of shingles later on.
I could not remember having chicken pox so when my husband got shingles I was concerned. He was miserable, he hurt and itched at the same time. A titer test told me that I indeed had chicken pox.
I got the shingles vaccine immediately.
Thanks.