Shingrix induces persistent immune responses in older adults, regardless of Zostavax dose
Two doses of the recombinant herpes zoster vaccine Shingrix induced “strong and persistent” immune responses in older adults, irrespective of whether they previously received the live-attenuated herpes zoster vaccine, Zostavax, according to results from a study published in The Journal of Infectious Diseases.
“Our results further support the U.S. Advisory Committee on Immunization Practices (ACIP) recommendation of Shingrix for immunocompetent adults who previously received Zostavax,” Alemnew Dagnew, MD, MSc, senior clinical research and development lead at GlaxoSmithKline Vaccines, told Healio. “Both anti-[glycoprotein E (gE)] antibody and gE-specific CD4 T-cell responses persist through 1 year following Shingrix vaccination, with no apparent differences between previous Zostavax recipients and Zostavax-naive study participants.”
Dagnew said the findings indicate that the persistence of immune responses to Shingrix — which has been shown in previous research to last a decade — “may also be expected in previous Zostavax recipients.”
“However, long-term follow-up studies may be required to definitively address this question,” he added.
Dagnew and colleagues group-matched 215 adults aged 65 years or older who had been previously vaccinated with Zostavax at least 5 years earlier with 215 Zostavax-naive individuals and vaccinated them with Shingrix. They assessed gE-specific humoral and cell-mediated immune responses, polyfunctional gE-specific CD4 T-cell responses, safety and confirmed herpes zoster cases.
According to the researchers, 32.5% of previous Zostavax recipients had CD4 T cells expressing one marker at 12 months, whereas 26.3% of Shingrix recipients who did not previously receive Zostavax showed CD4 T cells expressing one marker at 12 months. Results showed that anti-gE antibody concentrations, gE-specific CD4 T-cell frequencies and activation marker profiles were similar between the two groups. Safety outcomes were also found to be similar.
“Unlike the previous study in which Zostavax-naive only individuals were included, our study has novel data from both Zostavax recipients and Zostavax-naive individuals in terms of Shingrix-elicited polyfunctional immune responses and correlation between anti-gE antibody concentrations and CD4[2+] T-cell frequencies,” Dagnew said.
Dagnew noted that it is “encouraging” to demonstrate that prior vaccination with Zostavax does not interfere with the immune responses to Shingrix in older adults, further supporting the ACIP’s decision.
He cautioned that time intervals less than 5 years between the previous Zostavax dose and subsequent Shingrix doses have not been evaluated in his study, but “there are no scientific data or theoretical concerns to indicate that Shingrix would be less safe or effective when administered at an interval of less than 5 years.”
“However, ACIP notes that Shingrix should not be given within 2 months following receipt of Zostavax,” he said. – by Eamon Dreisbach
Disclosure: Dagnew reports being an employee of the GSK group of companies and holding shares in the GSK group of companies as part of employee remuneration. Please see the study for all other authors’ relevant financial disclosures.