The 2018 flu is one of the most complex in many years. Although seen as a H3N2 avian flu, the H3N1 swine flu virus has been the underlying base of all flu since the pandemic years ago. The swine flu virus has the unique feature that humans cannot develop effective antibodies so it circulates endlessly in the population.
Flus are delivered by parasites which contain the flu viruses, other parasites, fungi, biofilm, and other pathogens. The parasites endlessly replicate reproducing all the pathogens which makes flu long lasting.
This particular flu repeats itself. People get better, then relapse, then get better and relapse. Frequencies have been included to stop the relapses.