High-Dose Influenza Vaccine in Nursing Homes

SUMMARY: This nationally representative study samples from estimated 6782 Medicare-certified
nursing homes co-located within 50 miles of the 122 cities reporting to Center for Disease
Control and Prevention (CDC) weekly influenza surveillance. In total, 1000 facilities will be
enrolled for random assignment to either: 1) the licensed high dose (HD) trivalent influenza
vaccine (High-Dose Fluzone [HD vaccine]), or 2) the standard dose (SD) trivalent influenza
vaccine (Fluzone [SD vaccine]) for their residents. Additionally, half the facilities will
receive free SD vaccine for their staff and the remaining facilities will practice usual care
(no free vaccine) for staff.

BACKGROUND: Influenza and pneumonia (P&I) are leading infectious causes of hospitalization
and mortality in community-dwelling older adults and residents of long-term custodial care
facilities or nursing homes (NH), and produce substantial annual health care costs. The
elderly incur over 90% of this disease burden and NH residents are especially vulnerable
given immune senescence, multimorbidity, and close living quarters. While hospitalization
rates for NH residents vary considerably between facilities, most occur during the sixteen
weeks of peak influenza activity annually. Influenza vaccination, a mainstay in prevention,
is recommended in the U.S. for all individuals six months of age and older. Vaccination
associates with reduced rates of stroke, heart attack, hospitalization, and death in
non-institutional older adult populations. However, the benefit of influenza vaccine for the
elderly in general has been questioned, a salient concern for frail elderly, such as NH
residents. Influenza vaccination rates vary substantially between nursing homes. Influenza
vaccine response declines with advancing age, indicating the need for a better vaccine.

OBJECTIVES: The primary objective is to estimate the differences in all-cause hospitalization
rates during influenza season experienced by long-stay nursing home residents, between
facilities using HD vaccine vs. SD vaccine. The secondary objective is to estimate the
differences in the likelihood of Activities of Daily Living (ADL) functional decline and
mortality rates in the study nursing homes.

Inclusion Criteria:

- Long-term care facilities within 50 miles of one of the 122 cities that serve as CDC
surveillance sites

Exclusion Criteria:

- Facilities already systematically administering HD vaccine to their residents

- Facilities having fewer than 50 long-stay residents

- Hospital-based facilities

- Facilities with more than 20% of the population under age 65

- Facilities not submitting Minimum Data Set (MDS) data