We have shown that sialylated Fc compounds can inhibit agglutination of human erythrocytes by two genetically divergent influenza A (H1N1) and influenza B (Hong-Kong) viruses using the WHO standard  haemagglutination inhibition assay (HIA). Although HIA is a good correlate for the potential in vivo efficacy of these reagents, this work needs to be supported with more demanding virus neutralisation (VN) experiments, the aim of this application. This approach will provide the extra data and justification  required to support onward commercialisation in an application to the MRC DPFS scheme for further testing of the compounds in ferret and/or primate models prior to phase 1 clinical testing in humans.