Human beings (8) disease (7) disease (7) Patients (5) Patients (5) effect (4) Lungs (4) Diseases (4) Models (4) mortality (3) immunity (3) age (3) approach (3) Mortality (3) Diseases (3) Vaccination (3) Mortality (3) Infection (3) Immunity (3) Example (3) Animals (3) Age (3) Vaccination (3) Age (3) cohort (3) society (2) science (2) risk (2) need (2) model (2)