Influenza vaccine manufacturers require antigenically relevant vaccine viruses that have good manufacturing properties and are safe to use. In developing pandemic vaccine viruses, reverse genetics has been employed as a rational approach that can also be used effectively to attenuate the highly virulent H5N1 virus and at the same time place the H5 HA and N1 NA on a background of PR8, a virus th...

A natural reassortant influenza A virus consisting of seven genome segments from pandemic (H1N1) 2009 virus and a neuraminidase segment from a Eurasian porcine H1N1 influenza A virus was detected in a pig herd in Germany. The obvious reassortment compatibility between the pandemic (H1N1) 2009 and H1N1 viruses of porcine origin raises concern as to whether swine may become a reservoir for furthe...

BACKGROUND Oseltamivir has been used as a drug of choice for the prophylaxis and treatment of human influenza A(H1N1)pdm09 infection across the world. However, the most frequently identified oseltamivir resistant virus, influenza A(H1N1)pdm09, exhibit the H275Y substitution in NA gene. OBJECTIVES This study aimed to determine the prevalence and phylogenetic relationships of oseltamivir resist...

Levels of preexisting antibodies to the hemagglutinin of pandemic influenza A(H1N1) 2009 (hereafter pandemic H1N1) virus positively correlate with age. The impact of contemporary seasonal influenza vaccines on establishing immunity to other pandemic H1N1 proteins is unknown. We measured serum antibodies to the neuraminidase (NA) of pandemic H1N1 in adults prior to and after vaccination with sea...

BACKGROUND The human B-cell response to natural influenza virus infection has not been extensively investigated at the polyclonal level. METHODS The overall B-cell response of patients acutely infected with the 2009 pandemic influenza A(H1N1)pdm09 virus (A[H1N1]pdm09) was analyzed by determining the reactivity of plasmablast-derived polyclonal antibodies (PPAbs) to influenza proteins. Recipie...

BACKGROUND No examination of simultaneous vaccination against pandemic H1N1 and the seasonal influenza virus strains, in children with cancer receiving chemotherapy, are yet published. We investigated the immunogenicity of a whole-virion, inactivated, adjuvanted pandemic H1N1, and seasonal influenza vaccines administered simultaneously to children with cancer undergoing chemotherapy. PROCEDUR...

BACKGROUND Recent pandemics of influenza A H1N1pdm09 virus have caused severe illness, especially in young people. Very few studies on influenza A H1N1pdm09 in post-pandemic periods exist, and there is no information on the severity of both seasonal influenza A(H1N1) and A(H3N2) from the same season, adjusting for potential confounders, including vaccine. METHODS AND RESULTS We performed a re...

BACKGROUND The population-based impact of infection with swine origin influenza A (H1N1) virus infection was not clear in the early days of the epidemic towards the end of May 2009. Australia had seven confirmed cases by 22 May 2009. We aimed to compare available data on swine origin influenza A (H1N1) virus infection overseas with seasonal influenza A (H1N1) virus infection in Australia to ass...

BACKGROUND In response to the novel influenza A H1N1 outbreak in the NY City area, 6090 patient samples were submitted over a 5-week period for a total of 14,114 viral diagnostic tests, including rapid antigen, direct immunofluorescence (DFA), viral culture and PCR. Little was known about the performance of the assays for the detection of novel H1N1 in the background of seasonal H1N1, H3N2 and ...

INTRODUCTION Little is known regarding compliance with management guidelines for epidemic influenza in adult emergency department (ED) settings during the 2009 novel influenza A (H1N1) epidemic, especially in relation to the Centers for Disease Control and Prevention (CDC) guidance. METHODS We investigated all patients with a clinical diagnosis of influenza at an inner-city tertiary academic ...