Hello,
There is nothing to worry for you.
The virus that causes zoster can be passed on to others, but they will develop
chicken pox, if susceptible, not zoster.
Shingles is much less contagious than chicken pox because chicken pox can be spread through the air, whereas spread of shingles occurs only with direct contact or indirect contact with the
blister fluid which contains the virus particles. A person who has never had chicken pox may contract chicken pox by exposure to the shingles
rash.
But since you had chicken pox in your child hood, you can't get chicken pox now.
You also had shingles
vaccine,so there is nothing to worry and just relax.
Zoster occurs only if chicken pox virus gets reactivated but how it gets reactivated,is not known.It is said that weak immune system results in re activation of virus and this generally happens in people above the age of 50 years.However you appear safe.
Thanks