A new study has reported a rare instance of shingles reactivation following vaccination with the recombinant zoster vaccine (RZV), Shingrix, manufactured by GSK. The case, detailed in a recent publication, involved a 59-year-old male who developed herpes zoster ophthalmicus (HZO) after receiving the RZV immunization. This finding suggests that while RZV is highly effective, rare adverse events, including shingles reactivation, can occur.
The patient presented with a rash on the nasolacrimal area, forehead, and V1 dermatome, accompanied by facial tingling, nine days after RZV administration. Initial treatments with amoxicillin, valacyclovir, and eye drops proved ineffective, leading to hospitalization. The patient tested negative for herpes simplex virus but positive for varicella-zoster virus (VZV). He was subsequently treated with mupirocin and a full course of valacyclovir, leading to resolution of the V1 dermatome rash within 20 days.
Background on Shingles and Vaccination
Shingles, caused by the reactivation of the varicella-zoster virus (VZV), manifests as a painful, blistering rash. The FDA approved Zostavax (ZVL; Merck & Co., Inc.) in 2006 for the prevention of VZV. RZV was subsequently approved in 2017 as an updated vaccine. The CDC's Advisory Committee on Immunization Practices recommends RZV as the preferred vaccine due to its superior efficacy and safety profile compared to ZVL, demonstrating approximately 90% efficacy against shingles across all age groups in clinical trials. RZV is administered intramuscularly in two doses, spaced two to six months apart.
Mechanism of Action and Immunological Response
RZV utilizes glycoprotein E, a surface protein, combined with the adjuvant ASO1B, composed of monophosphoryl lipid A and saponin. This combination generates a robust and long-lasting immunological response, proving more effective in reducing herpes zoster (HZ) incidence, particularly in older adults, compared to ZVL.
Implications and Recommendations
Despite the established benefits of RZV, this case highlights the importance of continued monitoring for potential adverse events. While dermatomal reactions post-RZV vaccination have been reported, they were not observed in initial clinical trials. The study authors emphasize that healthcare providers should remain vigilant and aware of the possibility of rare adverse reactions and reactivation events following RZV administration.
"This underscores the need for constant monitoring and assessment of the RZV. Further studies are necessary to better understand how the immunomodulatory effects of RZV may provoke reactivation of HZ," the study authors stated.
