H7N9: the stealth bomber virus.

As described by EpiVax Inc. previously and now described in a scientific paper in Human Vaccine and Immunotherapeutics, the H7N9 virus is not just stealthy in poultry, its also hard to find in humans. There is concern over whether it will be possible to produce a vaccine that will be effective against a virus with such low predicted immunogenic potential. 

An H7N9 vaccine, without the right concoction of boosting additives, is predicted to be a poor trigger of our immune system's response to it. This is because H7N9 doesn't have as many T cell epitopes as other flu viruses...these are the bits recognized by important white blood cells that fight infection and shorten disease. Because of this human 'stealth' capability, it may evade the human response. 

This has obvious implications for disease (more severe if the host cannot shut the virus down quickly) and may also have implications for the usefulness of existing serodiagnostic (virus-specific antibody-detecting) assays.