In a study, polymerase chain reaction–confirmed second episodes of herpes zoster occurred in 2 of 660 patients receiving a placebo and 1 of 321 patients receiving ZVL.
Herpes zoster is the result of reactivation of the varicella zoster virus (VZV) that established latency in sensory and autonomic neurons during primary infection. Shingles Prevention Study results show that the same virus causes recurring shingles.
The study, a large efficacy trial of live attenuated Oka/Merck zoster vaccine (ZVL), enrolled 38,546 immunocompetent participants 60 years or older. They were actively followed for a mean of 3.13 years after receiving a placebo or the vaccine.
Polymerase chain reaction—confirmed second episodes of herpes zoster occurred in 2 of 660 patients receiving a placebo and 1 of 321 patients receiving ZVL. An additional 2 ZVL vaccine recipients experienced a second episode of herpes zoster in the long-term persistence substudy. Among those 5 participants, the second episodes occurred between 12 and 28 months apart. Investigators considered 1 of the 5 participants immunocompromised at the onset of his first and second episodes of herpes zoster.
The investigators used VZV DNA isolated from rash lesions to sequence the fulllength VZV genomes. The results indicated that the VZV genomes from the first and second episodes of herpes zoster in each of the 5 patients were caused by the same strain. The authors noted that their results are consistent with those of previous studies, which suggested that the risk of herpes zoster recurrence has been generally greater in female patients than in male patients.
Harbecke R, Jensen NJ, Depledge DP, et al. Recurrent herpes zoster in the Shingles Prevention Study: are second episodes caused by the same varicella-zoster virus strain? Vaccine. 2020;38(2):150-157. doi: 10.1016/j.vaccine.2019.10.038.