Zanamivir administered once daily is efficacious and well tolerated in the prevention of influenza for a 4-week period in healthy adults.

Ether treatment was studied as a method of increasing the ability of type B influenza antigen to detect antibody by hemagglutination inhibition. Comparisons were made with the untreated antigen, with an eluate made from the same virus, and with a standard type B antigen of an earlier virus. Results were evaluated based on the comparative ability to detect rises in antibody titer, as well as the relative frequency of antibody prevalence determined by each method. The ethertreated antigen was far superior to the untreated antigen in both respects; it was also superior to the eluate, although the difference was less pronounced. The treated antigen performed better than the standard type B antigen in detecting antibody in children, but there was little difference in adults. This pattern was felt to be a result of the closer relation of the treated antigen to the infecting strain. The method is, therefore, proposed as a means of producing more reactive antigens of currently circulating strains of type B influenza virus.

Our objective was to identify predictors of severe acute respiratory infection in hospitalised patients and understand the impact of vaccination and neuraminidase inhibitor administration on severe influenza. We analysed data from a study evaluating influenza vaccine effectiveness in two Michigan hospitals during the 2014-2015 and 2015-2016 influenza seasons. Adults admitted to the hospital with an acute respiratory infection were eligible. Through patient interview and medical record review, we evaluated potential risk factors for severe disease, defined as ICU admission, 30-day readmission, and hospital length of stay (LOS). Two hundred sixteen of 1119 participants had PCR-confirmed influenza. Frailty score, Charlson score and tertile of prior-year healthcare visits were associated with LOS. Charlson score >2 (OR 1.5 (1.0-2.3)) was associated with ICU admission. Highest tertile of prior-year visits (OR 0.3 (0.2-0.7)) was associated with decreased ICU admission. Increasing tertile of visits (OR 1.5 (1.2-1.8)) was associated with 30-day readmission. Frailty and prior-year healthcare visits were associated with 30-day readmission among influenza-positive participants. Neuraminidase inhibitors were associated with decreased LOS among vaccinated participants with influenza A (HR 1.6 (1.0-2.4)). Overall, frailty and lack of prior-year healthcare visits were predictors of disease severity. Neuraminidase inhibitors were associated with reduced severity among vaccine recipients.

No abstract