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Varicella Zoster Virus (VZV) Cell-Mediated Immunity 3 Years After the Administration of Zoster Vaccine to Septuagenarians Immunized 10 Years Previously

Year: 2016

Type: article

Abstract: Background. Zoster vaccine (ZV) significantly decreases the incidence and morbidity of herpes zoster (HZ), but the vaccine-conferred protection against the incidence of HZ wanes over time, suggesting that a booster dose may be warranted. We previously showed that a booster dose of ZV administered ≥10 years after the initial dose to adults ≥70-year old is safe and well-tolerated. Cell-mediated immunity (CMI) was significantly higher before and after vaccination in the boosted group compared with the first-time immunized controls. Here we present the magnitude and persistence of VZV CMI three years after booster vaccination. Methods. ZV was administered to participants ≥70-year old as a second dose (G1; N = 201) to subjects who had received ZV ≥10 years previously and as a first dose to age-matched controls (G2; N = 199). CMI was measured by dual-color IL2 and IFNγ FluoroSPOT. The same assay control was used during the entire study to ensure consistency of the results. Results. At 3 years after ZV administration, 156 of 201 G1 and 137 of 199 G2 participants contributed to analysis. The number of VZV-specific IFNγ + IL2 + /− effector, IFNγ + / − IL2+ memory and IFNγ + IL2+ effector-memory spot forming cells (SFC) did not differ between entry and 3 years in either group (p ≥ 0.45). The SFC comparison between the two groups showed similar IFNγ + IL2 + /− and IFNγ + / − IL2+ SFC at 3 years (p ≥ 0.14) and a trend towards higher IFNγ + IL2+ SFC in G1 versus G2 (p = 0.07). Conclusion. VZV CMI in adults ≥70-year 3 years after a second (booster) dose of ZV was similar to the baseline. At 3 years, the boosted group maintained only a marginal advantage in IFNγ + IL2+ effector-memory T cells and had similar IFNγ + / − IL2+ total memory and IFNγ + IL2 + /− total effector T cells compared with the first-time immunized group. The clinical significance of these findings remains to be determined. Disclosures. A. Weinberg, Merck: Investigator, Research grant; M. Levin, Merck: Investigator, Research support; K. Schmader, Merck: Investigator, Research support; M. Johnson, Merck: Investigator, Research support; Y. Caldas, Merck: Investigator, Research support; J. Canniff, Merck: Investigator, Research support; A. Cho, Merck: Investigator, Research support; B. Mccarson, Merck: Employee, Salary; J. Martin, Merck: Employee, Salary; Z. Popmihajlov, Merck: Employee, Salary

Source: Open Forum Infectious Diseases

DOI: 10.1093/ofid/ofw172.578