Avian Influenza Viruses Infect Primary Human Bronchial Epithelial Cells Unconstrained by Sialic Acid α2,3 Residues

Avian influenza viruses (AIV) are an important emerging threat to public health. It is thought that sialic acid (sia) receptors are barriers in cross-species transmission where the binding preferences of AIV and human influenza viruses are sias α2,3 versus α2,6, respectively. In this study, we show that a normal fully differentiated, primary human bronchial epithelial cell model is readily infected by low pathogenic H5N1, H5N2 and H5N3 AIV, which primarily bind to sia α2,3 moieties, and replicate in these cells independent of specific sias on the cell surface. NHBE cells treated with neuraminidase prior to infection are infected by AIV despite removal of sia α2,3 moieties. Following AIV infection, higher levels of IP-10 and RANTES are secreted compared to human influenza virus infection, indicating differential chemokine expression patterns, a feature that may contribute to differences in disease pathogenesis between avian and human influenza virus infections in humans

Gain-of-function experiments on H7N9

Since the end of March 2013, avian a influenza viruses of the H7N9 subtype have caused more than 130 human cases of infection in China, many of which were severe, resulting in 43 fatalities. Although this A(H7N9) virus outbreak is now under control, the virus (or one with similar properties) could reemerge as winter approaches. To better assess the pandemic threat posed by A(H7N9) viruses, NIAID/NIH Centers of Excellence in Influenza Research and Surveillance (CEIRS) investigators and other expert laboratories in China and elsewhere have characterized the wild-type avian A(H7N9) viruses in terms of host range, virulence, and transmission, and are evaluating the effectiveness of antiviral drugs and vaccine candidates. However, to fully assess the potential risk associated with these novel viruses, there is a need for additional research including experiments that may be classified as 'gain-of-function' (GOF). Here, we outline the aspects of the current situation that most urgently require additional research, our proposed studies, and risk-mitigation strategies

Pause on avian flu transmission research

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Transmission studies resume for avian flu

Lette

Improving reliability of judgmental forecasts

All judgmental forecasts will be affected by the inherent unreliability, or inconsistency, of the judgment process. Psychologists have studied this problem extensively, but forecasters rarely address it. Researchers and theorists describe two types of unreliability that can reduce the accuracy of judgmental forecasts: (1) unreliability of information acquisition, and (2) unreliability of information processing. Studies indicate that judgments are less reliable when the task is more complex; when the environment is more uncertain; when the acquisition of information relies on perception, pattern recognition, or memory; and when people use intuition instead of analysis. Five principles can improve reliability in judgmental forecasting: 1. Organize and present information in a form that clearly emphasizes relevant information. 2. Limit the amount of information used in judgmental forecasting. Use a small number of really important cues. 3. Use mechanical methods to process infomation. 4. Combine several forecasts. 5. Require justification of forecasts