New research that looks at the durability of influenza vaccination indicates ebbing protection just months after the jab.
Maximum influenza vaccine efficacy in adults occurred shortly after vaccination, followed by an average decline of 8% to 9% each month and an even swifter drop among older adults.
Even a 1- or 2-month delay in annual flu vaccination could improve vaccine effectiveness by 10% to 20%, according to the study, published August 15 in Clinical Infectious Diseases.
Analyzing vaccine timing relative to influenza-associated hospitalizations among more than 5500 adults, the findings are broadly consistent with both early and more recent studies, said study author Jill Ferdinands, PhD, an epidemiologist in the Influenza Division of the National Center for Immunization and Respiratory Diseases at the US Centers for Disease Control and Prevention (CDC).
