Background Annual influenza vaccination is recommended for older adults but repeated
vaccination with standard-dose influenza vaccine has been linked to reduced …

Background Annual influenza vaccination is recommended for older adults but repeated
vaccination with standard-dose influenza vaccine has been linked to reduced …

Background Enhanced influenza vaccines may improve protection for older adults, but
comparative immunogenicity data are limited. Our objective was to examine immune …

Background Many health authorities recommend influenza vaccination of older adults to
reduce disease burden. We hypothesized that in tropical and subtropical areas with more …

Background The 2014/15 influenza season in Canada was characterized by an early
epidemic due to vaccine-mismatched influenza A (H3N2) viruses, disproportionately …

Background The effectiveness of repeated vaccination for seasonal influenza remains
controversial. Here, we measured antibody responses to the influenza virus (A/H1N1 …

Background Little is known about factors associated with maintenance of hemagglutinin
inhibition (HAI) antibodies after influenza vaccination in older adults. Methods Adults≥ 50 …

Background: Since 2007, trivalent inactivated influenza vaccine has been provided free-of-
charge to older adults aged≥ 60 years in Beijing, China, but the data regarding influenza …

BACKGROUND: The recent H1N1 pandemic virus that emerged in 2009 resulted in high
morbidity rates mainly in younger individuals, albeit with relatively low mortality. We …

Antigenic drift is a major driver of viral evolution and a primary reason why influenza
vaccines must be reformulated annually. Mismatch between vaccine and circulating viral …