Immunogenicity of Varicella Zoster Vaccine and Immunologic Predictors of Response in a Cohort of Elderly Nursing Home Residents.
Lelic A, Verschoor CP, Lau VW, Parsons R, Evelegh C, Bowdish DM, Bramson JL, Loeb MB.
BACKGROUND: Little is known about the immunogenicity of live-attenuated Oka/Merck varicella zoster vaccine (VZV) vaccine in frail nursing homes residents nor about immune phenotypes associated with a response.
METHODS: A cohort of 190 frail nursing home residents between the ages of 80 and 102 years and a cohort of 50 community dwelling seniors, ages 60 to 75 years, a comparison group, were vaccinated with the VZV vaccine. IFN-γ ELISpot assay was measured prior to and six-weeks following vaccination. Cellular markers of immunosenescence were measured in the nursing home elderly.
RESULTS: The average number of IFN-γ spot forming cells at baseline was significantly lower in the nursing home elderly than in the community dwelling seniors. However, following vaccination, the VZV immune response increased in both cohorts and no difference was noted in the fold difference of the response between the two cohorts. Upon further examination of the frail elderly, we found that higher frequencies of T regulatory cells and CMV-specific CD4+ T cells correlated negatively with the magnitude of VZV-specific responses.
CONCLUSIONS:The Oka/Merck VZV vaccine induces VZV-immunity in elderly nursing home residents similar to the immunity produced in community dwelling seniors.
CLINICAL TRIALS REGISTRATION: NCT01328548.