Background Predominance of 2 antigenically drifted influenza viruses during the 2019–2020
season offered an opportunity to assess vaccine effectiveness against life-threatening …

OBJECTIVE. The goal was to estimate the effectiveness of influenza vaccination against
laboratory-confirmed influenza during the 2003–2004 and 2004–2005 influenza seasons in …

Background. No studies have examined the effectiveness of influenza vaccine against
intensive care unit (ICU) admission associated with influenza virus infection among children …

Abstract Background Annual United States (US) estimates of influenza vaccine effectiveness
(VE) in children typically measure protection against outpatient medically attended influenza …

Objective To measure vaccine effectiveness (VE) in preventing influenza-related health care
visits among children aged 6 to 59 months during 2 consecutive influenza seasons. Design …

OBJECTIVES. Influenza is a leading cause of illness among children. Studies rarely have
measured influenza vaccine effectiveness among young children, particularly when …

To estimate the effectiveness of influenza vaccine against medical care visits for laboratory-
confirmed influenza in young children we conducted a matched case–control study in …

BACKGROUND: Influenza A (H1N1) pdm09 viruses initially predominated during the US
2018–2019 season, with antigenically drifted influenza A (H3N2) viruses peaking later. We …

The effectiveness of influenza vaccine over multiple influenza seasons in children less than
5 years of age has not been well studied. This is especially important to assess because of …

Background. Influenza vaccines may be reformulated annually because of antigenic drift in
influenza viruses. However, the relationship between antigenic characteristics of circulating …