According to study findings presented at the virtual 2021 American Society of Clinical Oncology (ASCO) Annual Meeting, patients with chronic lymphocytic leukemia (CLL) are prone to infection due to impaired humoral immunity as a complication of the disease, treatments received, and age at diagnosis.

Herpes zoster (HZ), a viral infection from the reactivation of varicella-zoster virus and better known as shingles, is common among immunocompromised patients. However, even with an existing HZ vaccine, vaccine rates are low.

Thus, Nirav Antao, DO, Department of Internal Medicine, St. Louis University, and colleagues developed a study to determine the effect of the HZ vaccine on rates of HZ infection in patients with CLL.

A total of 7,155 patients with CLL who received treatment for HZ were identified using the Veterans Administration Central Cancer Registry (VACCR) between September 1999 and October 2015. Of that, 2,640 patients (36.9%) received first-line chemotherapy and 1,161 patients (16.2%) received second-line chemotherapy. There were 1115 cases of HZ detected throughout both arms and 615 patients (8.6%) had a HZ vaccination.

Patients with HZ were younger (mean age, 68 vs 69.8 years; P = .001), had similar co-morbidities, and were more likely to get treatment for CLL (58.1% vs 33%; P <.001).

Using a time-varying analysis, HZ vaccines decreased the risk of developing HZ (hazard ratio [HR], 0.71; 95% CI, 0.49-1.04; P = .082). When adjusting for age and co-morbidity, patients with CLL treated with first-line chemotherapy had higher risk of HZ (HR 2.34; 95% CI, 2.02-2.71; P <.001) compared to those who never received therapy. Second-line chemotherapy increased the risk for HZ (HR, 1.32; 95% CI, 1.13-1.55; P <.001) more than first-line treatment.

Researchers concluded that HZ is prevalent in patients with CLL and affects younger patients who need chemotherapy. The risk of developing HZ also increases in patients of first- and second-line chemotherapy. In the time-varying analysis, a trend toward decreased infection was seen in patients with the HZ vaccine.

“Further studies in a more modern cohort that assess infection risk using a larger vaccinated group with the newer and more effective HZ vaccine are warranted,” reported Dr Antao and colleagues.—Emily Bader

Antao N, Chilkulwar AR, Luo S, et al. Herpes zoster in chronic lymphocytic leukemia: Effect of vaccination and treatment. Presented at: the 2021 ASCO Annual Meeting; June 4-8, 2021; virtual. Abstract 7527