ProMED reported a new cases of H7N9 influenza today – suggesting that H7N9 will be re-emerging in China this winter. Three cases have been reported this Fall within the period of about a month – relatively early for influenza season. While many groups (including the Chinese government) report having developed an H7N9 vaccine, the efficacy of these vaccines remains to be determined. EpiVax published a report on H7N9 early in the epidemic (http://bit.ly/H7N9Project) that describe the low T cell epitope content of the H7N9 HA protein, which is the primary component of influenza vaccines. The H7N9 was predicted to be extremely low, raising concerns about whether the standard approach to making flu vaccines would be effective against influenza, in this particular case.
The latest case of H7N9 influenza occurred in a 3 year-old boy in the Guangdong province of China. This is the third H7N9 reported this autumn in China adding to the 134 cases reported for 2013 by the end of August. This may indicate that China may see a resurgence of H7N9 cases, in conjunction with non-avian seasonal influenza, with the onset of the winter flu season. Furthermore the previous H7N9 epidemic largely affected adults, with children experiencing minimal symptoms. The circumstances of how the child was infected have not been disclosed but it does not appear to be connected with the two previous cases reported this autumn. Chinese officials have been able to significantly reduce the transmission of H7N9 infections by closing down live poultry markets. Hopefully we shall see an emergence of a more effective H7N9 vaccine to prevent further epidemics.