From the Guidelines
Yes, varicella zoster shingles can occur in vaccinated adults, although the risk is significantly reduced with the use of vaccines like Shingrix, which has been shown to be over 90% effective in preventing shingles 1. The vaccine efficacy of Shingrix, a recombinant zoster vaccine, was demonstrated in the ZOE-50 and ZOE-70 trials, with a vaccine efficacy of 97.2% and 89.8%, respectively, in preventing herpes zoster (HZ) 1. Key points to consider include:
- The persistence of protection conferred by Shingrix was maintained above 83.3% for up to 8 years, and decreased to 73% at 10 years 1.
- Shingrix is recommended for immunocompetent adults aged 50 years and older, with a preference over Zostavax (ZVL) due to its higher efficacy and longer duration of protection 1.
- While Shingrix is associated with a higher rate of injection-site and systemic reactions compared to ZVL, there were no differences in serious adverse events (SAEs) between the two vaccines 1.
- The use of Shingrix is recommended for adults 50 and older, regardless of prior varicella vaccination status, as it provides significant protection against shingles and its complications 1.
From the Research
Varicella Zoster Shingles in Vaccinated Adults
- Varicella zoster shingles, also known as herpes zoster, is a neurocutaneous disease caused by the reactivation of the varicella zoster virus (VZV) 2.
- The virus can remain latent in the dorsal ganglia of the spine after resolution of the varicella episode and reactivate years later, causing shingles 2.
- Vaccination with an attenuated form of the VZV can activate specific T-cell production, avoiding viral reactivation 2.
- Two types of herpes zoster vaccines are currently available: the live attenuated zoster vaccine (LZV) and the recombinant zoster vaccine (RZV) 2, 3.
Effectiveness of Vaccines in Preventing Herpes Zoster
- The LZV and RZV vaccines have been shown to be effective in preventing herpes zoster in older adults, with a lower cumulative incidence of herpes zoster in vaccinated participants compared to those who received a placebo 2.
- The RZV vaccine has been shown to have a higher vaccine efficacy, with an overall efficacy of 97.2% among participants 50 years of age or older 3.
- However, the vaccines can produce systemic and injection site adverse events of mild to moderate intensity 2, 3.
Risk of Herpes Zoster in Vaccinated Adults
- The risk of herpes zoster in adults immunized with varicella vaccine is similar to published data for the US population in the prevaccine era, with a rate of 1.00 case/1000 person-years 4.
- However, some studies suggest that vaccination may lead to an increase in the incidence of shingles, particularly in older adults 5.
- The mechanisms for maintaining immunity against varicella and zoster are critical for predicting the long-term effects of vaccination 5.