Hospital-based vaccination of older adult inpatients: comparison of two delivery models for influenza, COVID-19 and pneumococcal vaccines

Background: Vaccination coverage for influenza, SARS-CoV-2 and pneumococcal disease among older Australians remains suboptimal. Hospital admission is an underutilised opportunity for the vaccination of older adults. Methods: We conducted a 12-week prospective, single-centre evaluation at a tertiary hospital in Australia (August–November 2024). Inpatients aged ≥ 65 years admitted under cardiology, geriatrics, geriatric rehabilitation, respiratory and infectious diseases were screened for eligibility for National Immunisation Program (NIP)-recommended vaccines (influenza, SARS-CoV-2, conjugate pneumococcal). Stage 1 (weeks 1–6) involved academic detailing of medical officers (including education on the clinical benefit and standard of care for older adult immunisation) and weekly reminders to vaccinate as a part of routine care. During Stage 2 (weeks 7–12), we stopped giving reminders to medical officers, and a part-time vaccine prescriber (5 h/week) screened, consented and prescribed vaccines. Barriers to vaccination were recorded during both stages. We compared vaccination uptake between Stage 1 and Stage 2. Results: Of the 851 inpatients screened, 649 were eligible for 1,410 vaccines (76.3%), and 73 vaccinations were administered (5.2%). Overall uptake increased from 19/710 (2.7%) vaccinations during Stage 1, to 54/700 (7.7%) vaccinations during Stage 2 (OR 3.04, 95% CI 1.75–5.49; p < 0.001). An increase in vaccination uptake was observed for SARS-CoV-2 (Stage 1: 1/286, 0.3%; Stage 2: 12/280, 4.3%; OR 12.7, 95% CI 1.86–546.03) and pneumococcal vaccination (Stage 1: 8/247, 3.2%; Stage 2: 30/253, 11.9%; OR 4.0, 95% CI 1.75–10.34), but not for influenza (Stage 1: 10/177, 5.6%; Stage 2: 12/167, 7.2%; OR 1.29, 95% CI 0.5–3.44). Conclusions: Academic detailing and regular reminders for medical officers to vaccinate was associated with lower vaccination uptake of older adult inpatients than the use of a part-time vaccine prescriber.