What Causes Outbreak Of Shingles Despite Taking Vaccinations?

Hi, I am a 58 year old female and have had shingle outbreaks on my face since I was 12 years. These outbreaks occur about every 3-4 years. I took the shingle vaccine when I\I turned 50. I am on my second dosage of 3000 mg of Valtrex for ten days I have had predisome tablets and shots and yesterday was prescribed lyrica. The outbreak began in February. Could there be another reason I keep having the shingles?