Guan, Yi, Amber Farooqui, Huachen Zhu, Wei Dong, Jia Wang, and David J Kelvin. 2013. “H7N9 Incident, Immune Status, the Elderly and a Warning of an Influenza Pandemic”. The Journal of Infection in Developing Countries 7 (04):302-7. https://doi.org/10.3855/jidc.3675.