715. VZV Cell-Mediated Immunity 3 Years After The Administration Of Zoster Vaccine To Septuagenarians Immunized 10 Years Previously
Session: Poster Abstract Session: Vaccines
Thursday, October 27, 2016
Room: Poster Hall
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 vs. 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.

Adriana Weinberg, MD1, Myron Levin, MD, FIDSA1, Kenneth Schmader, MD2, Michael Johnson, MD1, Yupanqui Caldas, MD1, Jennifer Canniff, MD1, Alice Cho, BS1, Barbara Mccarson, MD3, Jason Martin, MD3 and Zoran Popmihajlov, MD3, (1)University of Colorado Denver Anschutz Medical Campus, Aurora, CO, (2)Duke University, Durham, NC, (3)Merck & Co., Inc., Kenilworth, NJ

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

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