Influenza

Influenza is a viral respiratory infection that causes an acute febrile illness with myalgia, headache and cough, and can result in high morbidity and mortality rates during an epidemic. Annual epidemics are thought to result in between three and five million cases of severe influenza and between 250,000 and 500,000 deaths worldwide. 

There are occasional pandemics.  The deadly 1918 influenza pandemic infected 500 million people and killed 50-100 million, 3-5% of the population. [2]

Development of strategies for mitigating the severity of a new influenza pandemic is a top global public health priority. Treatment of clinical cases can reduce transmission, but only if antivirals are given within a day of symptoms starting. Given enough drugs for 50% of the population, household-based prophylaxis coupled with reactive school closure could reduce clinical attack rates by 40–50%. [1]

Anti viral drugs and vaccines show mixed results but are the first line of defence.  Once a new strain of influenza is identified it takes a few months for a vaccine to be developed and distributed however once available infection rates are considerably reduced.  

Aromatherapy.  Essential oils are used in personal care for their useful properties including antiseptic first aid for skin injuries and respiratory conditions. Wiping surfaces with diluted essential oils and diffusing essential oils in a room is useful.  Essential oils properties include both anti viral effects and immune stimulation.  Methods of use include diffusion and steam inhalation into the lungs.  Essential oils have the important feature that unlike drugs immunity to them is not acquired by viruses and bacteria. One studied antiseptic oil blend includes clove bud, cinnamon, pine, thyme, peppermint, lavender, rosemary.  There are also the oils of eucalyptus and tea tree,

Chinese medicinal herbs are a therapy of choice.  
Cochrane review of evidence

[1]  Strategies for mitigating an influenza pandemic
http://www.nature.com/nature/journal/v442/n7101/full/nature04795.html
[2] The 1918 Pandemic
http://en.wikipedia.org/wiki/1918_flu_pandemic