Attempt to develop universal flu vaccine
A brand new vaccine against seasonal flu has to be created once a year for both the northern and southern hemispheres.
The constant and rapid evolution of the virus means a vaccine which is effective this year could be useless by the next.
Scientists in Belgium are determined to beat the virus by producing a vaccine that works long-term, against many types of flu, including pandemic strains.
The Health Show is broadcast on BBC World News on Saturdays at 1010 and 2010 GMT and on Sundays at 0710 and 2310 GMT. The programme is supported by the Gates Foundation.