Recombinant Influenza Vaccination in U.S. Nursing Homes

Comparative Effectiveness of Recombinant Versus Standard Dose Quadrivalent Influenza Vaccine in U.S. Nursing Homes

Based on recent evidence on the mutation of the A/H3N2 strain in egg-grown vaccine, the investigators will study the quadrivalent recombinant influenza vaccine (RIV4, Flublok) compared to the standard dose quadrivalent vaccine (IV4) in a cohort of long-stay NH residents with a primary endpoint of all-cause hospitalization.

A study sample goal of 1000 U.S. NHs, housing approximately 112,000 overall residents and 92,000 over the age of 65 years, of whom 64,500 are long-stay NH residents, will be recruited for each of the 2019-20 and 2020-21 influenza seasons. Participating facilities will be randomly allocated in a 1:1 ratio to RIV4 or IV4 vaccine for their residents. Also, all staff must be offered the same vaccine in both allocation groups, in order to eliminate differences in transmission of influenza through staff to residents related to differences in vaccine-related protection of staff and will reduce heterogeneity between clusters. The Minimum Data Set from the NH resident assessment instrument will be evaluated from all evaluable facilities meeting inclusion criteria and will be cross-referenced to Medicare claims and drug use data.

Inclusion Criteria:

• Medicare-certified NHs with at least 50 long-stay residents ≥ 18 years of age
• Facilities with at least 80% of their long-stay population ≥ 65 years of age or at least 70 long stay residents ≥ 65 years of age that make up ≥ 45% of their total number of beds

Exclusion Criteria:

• Hospital-based facilities
• Facilities where Fluzone High-Dose or Fluad was used in the previous influenza season (2018-19 or 2019-20), or who's leadership plans to use one of these vaccines in the 2019- 2020 or 2020-21 season
• Facilities not submitting MDS data
• Facilities not in one of the 50 U.S. states