Adults with rheumatoid arthritis face significantly elevated risks for herpes zoster complications, but new research demonstrates that the recombinant zoster vaccine provides robust protection without triggering disease flares. Two complementary studies presented compelling evidence for both the efficacy and safety of RZV in this vulnerable population.
Vaccine Effectiveness Against Herpes Zoster
A large-scale retrospective cohort study through Kaiser Permanente Southern California examined 1,926 vaccinated and 5,746 unvaccinated adults with rheumatoid arthritis aged 50 and older. The research revealed that two doses of RZV delivered substantial protection against herpes zoster, with an adjusted vaccine effectiveness of 60.7% (95% CI, 41.0%-73.8%).
The protection remained consistent across different dosing intervals, with subgroup analysis showing 57.9% effectiveness (95% CI, 34.4%-73.0%) among participants who received doses between 4 weeks to 6 months apart. More notably, the vaccine demonstrated exceptional efficacy against postherpetic neuralgia, achieving 88.7% effectiveness (95% CI, 12.1%-98.5%).
Safety Profile in Inflammatory Conditions
Complementary safety data from an ongoing prospective study of 150 adults with inflammatory rheumatic and musculoskeletal diseases provided reassuring tolerability findings. The study included patients with rheumatoid arthritis, axial spondyloarthritis, and giant cell arteritis, with 21.3% having a previous history of herpes zoster.
Most adverse events occurred within days of vaccination, with 139 (46.8%) localized and 158 (53.2%) generalized adverse events reported through Month 3. Pain at the injection site was the most frequent adverse event, affecting 32.7% of patients, followed by fever (14.1%), fatigue (9.4%), and musculoskeletal pain (8.1%).
Disease Flare Risk Assessment
Critical safety analysis focused on the risk of triggering rheumatoid arthritis flares post-vaccination. The Kaiser Permanente study found no heightened risk of RA flares within 30 days of vaccination among 2,606 adults who received at least one RZV dose (RR, 1.02; 95% CI, 0.75-1.37).
The prospective study corroborated these findings, with disease flares reported at various follow-up points, but only 1.6-8.6% fulfilled predefined flare criteria. Lead author Uta Kiltz noted that "over the observed period of 12 months, this can be interpreted as a low rate of events." Only three patients required hospitalization due to disease flares - two with giant cell arteritis and one with rheumatoid arthritis.
Clinical Implications for High-Risk Populations
These findings address a critical gap in vaccination guidance for immunocompromised patients. Herpes zoster carries a lifetime risk of 25% in the general population, but patients with rheumatic and musculoskeletal diseases face elevated risks due to both advanced age and immunosuppression.
The European Alliance of Associations for Rheumatology (EULAR) recommends herpes zoster vaccination for high-risk patients with autoimmune and inflammatory conditions. However, live vaccines pose challenges for patients on immunosuppressive therapies, making the safety profile of the non-live recombinant vaccine particularly significant.
The recombinant zoster vaccine contains recombinant glycoprotein E, the major target of CD4+ T-cells, offering an alternative to live-attenuated versions. The research authors concluded that the findings support confidence in RZV safety for patients with inflammatory rheumatic and musculoskeletal diseases and indicate the efficacy and safety of RZV in immunocompromised populations.
