2B). Good selleck chemical correlation could be drawn between vaccine dose and total IgG levels to homologous and heterologous H7 strains as seen by the dose-dependent decrease of antibody levels in most cases. Moreover, we could detect considerable cross-reactivity

against subtypes H15 and H3 across all tested sera. Levels of neutralising antibodies elicited by each vaccine were measured by hemagglutination inhibition (HI) assay in which sera from vaccinated mice were evaluated for their ability to prevent virus-induced agglutination of turkey RBCs. Results show that the VLP-based H7 vaccine induced high HI-active antibody titres up to 1:40 for PR8:SH1 and up to 1:80 against PR8:AH1 (Table 1). Both VLP vaccines were also able to induce levels of HI antibodies that prevented virus-induced hemagglutination by a panel of divergent H7 strains of the Eurasian and the more distant North American lineage, with titres of up to 1:40. Single vaccination with the two higher SH1-VLP vaccine doses (3 μg and 0.3 μg) generated similar amounts of HI-active antibodies for all tested virus strains and negligible HI titres were measured for the lowest vaccine dose (0.03 μg). The second dose of SH1-VLP vaccine led to a 2-fold enhancement of average levels of HI-active

antibodies for most of the virus strains tested. No HI antibodies most were detected in the two control groups (naïve and M1-vaccinated mice). On 31 March Antiinfection Compound Library 2013, the Chinese

Health and Family Planning Commission notified the WHO of three cases of human infections with a novel influenza A (H7N9) strain [1], which has been the causative agent for 137 infections with a mortality rate of 33% as of 25 October. It remains unclear whether the virus will persist in the human reservoir and cause sporadic infections, or whether it will gain the ability to transmit from human to human through mutations or re-assortment [29]. Limited reports on new human incidences might be due to the shutdown of live poultry markets throughout the country. However, H7N9 may also follow a seasonal outbreak pattern similar to H5N1, therefore an epidemic could re-occur in fall [30]. Since no vaccine for H7N9 is available for humans, antivirals are the only treatment options, but bear the risk to yield treatment-resistant viruses, which were already associated with poor clinical outcome [6] and [7]. The potential threat of a pandemic outbreak serves as catalyst for enhanced research and vaccine development efforts in both academia and industry. Human H7 vaccines are underway and have been evaluated in preclinical [8], [9], [10], [11], [13], [14], [31] and [32] or phase I or I/II studies [12], [33], [34] and [35].