Vitamin D Supplementation And Varicella Zoster Virus Vaccine Responsiveness In Older Long-Term Care Residents

Objectives

• To determine the increase in Varicella-zoster virus (VZV)-specific cell-mediated immune response from pre-zoster vaccination to 3 weeks post-vaccination in nursing home residents after 4 months of high dose vs. standard dose vitamin D3 supplementation.
• In the same participants as Aim 1, to measure the association between pre-zoster vaccination 25-hydroxyvitamin D [25(OH)D] levels and the increase in VZV-specific cell-mediated immune response from pre- vaccination to 3 weeks post-vaccination.
• Characterize the phenotypic and functional VZV-specific T cell responses to Zostavax, including memory, effector, Th1/Th2, and homing receptor-bearing T cells in the high compared to low ELISPOT responders.

Hypotheses

• At baseline, higher serum 25(OH)D levels will be associated with higher levels of VZV-specific cell-mediated immunity (cross-sectional).
• At baseline, higher serum 25(OH)D levels, independent of vitamin D supplementation dose, will be associated with greater increases in VZV-specific cell-mediated immune responses to Zostavax, as measured by the interferon (IFN)-γ ELISPOT assay.
• Compared to standard dose, high dose vitamin D3 supplementation will enhance VZV-specific cell-mediated immune response to vaccination independent of baseline serum 25(OH)D levels.

Inclusion criteria

• Aged ≥ 60 years;
• Residing in a long-term care facility;
• Have not yet received VZV vaccine

Exclusion criteria

• terminal illness (expected survival <6 months);
• anticipated discharge within 12 months;
• unable to take whole or crushed tablets;
• active cancer, except squamous/basal cell carcinoma;
• severe malnutrition (body mass index <18 kg/m2);
• current immunosuppressive medications (including corticosteroids);
• renal failure (eGFR<15 mL/min/1.73m2);
• currently taking >800 IU/d vitamin D supplementation;
• history (or strong family history) of kidney stones;
• history of sarcoidosis or other granulomatous disorders associated with hypercalcemia;
• elevated baseline hypercalcemia (albumin-adjusted serum calcium >10.5 mg/dL);
• serum 25 (OH)D level ≥40 ngl/ml at baseline;
• inability to provide informed consent and no available healthcare proxy;
• inability of participant or proxy to speak/understand English.
• previous receipt of the Zostavax (anticipate <10% of trial;
• known allergy to gelatin, neomycin, or any other component of the vaccine.