Influenza: Misplaced Complacency

Dr. David J. Holcombe
Dr. David J. Holcombe

Most people shrug off the flu as an inevitable and annoying bother.  The fact remains, however, that this worldwide recurrent scourge, depending on the severity of the strain, kills anywhere from 3,000 to 30,000 Americans each year, many of them elderly.  Influenza A is not just a human affliction, but infects a host of birds and mammals, and can jump from species to species with remarkable regularity.  Influenza’s extraordinary capacity for genetic “antigenic shift and drift” allows it to mutate and recombine in new deadly combinations every year as it sweeps around the globe.


Although most Americans have only vaguely heard of the “Spanish Flu”, that particular pandemic killed around 50 million people worldwide (500,000 in the U.S. alone) in 1918 and resulted in more deaths than all those killed in the First World War (around 17 million).  While we now have antibiotics and intensive care units, the carnage from a 1918-like flu (with 2% mortality) would cause over a million deaths in Louisiana alone.


Flu vaccine must be altered each year to reflect the current strains of influenza.  This year, the trivalent (3 component) flu vaccine contains the H1N1 (A/California), H3N2 (A/Switzerland) and B (Phuuket) viral components.  These are updates from the 2014-2015 vaccines.  The quadrivalent (4 element) vaccine also contains an additional B (Brisbane) viral component.  Some newly approved vaccines include the jet injector device and Fluzone Intradermal Quadrivalent.  The appearance of a H3N2v (swine variant) in Michigan is being followed closely, but should not hinder anyone for getting vaccinated with the current preparations.


Although not 100% effective, the efficacy of flu vaccine usually approaches 60%.  During the 2014-15 flu season, the H3N2 strain underwent some antigenic drift (genetic changes) which reduced its effectiveness to as low as 23% protection.  But vaccination, despite whether it is by shot, injection or nasal spray, and even without a perfect match, still helps reduce the severity of the illness in those who get infected.  This is especially true in high risk groups including those over 65 and less than 2 years of age, pregnant women, the morbidly obese and the immune-compromised.  Readily available in supermarkets, physicians’ offices and other venues, flu vaccine cost is usually covered by most insurance plans, well aware of the benefits to their policy holders.


Why the largess from insurers?  Simply put, the cost of the vaccines is far less than the cost of the disease.  Flu causes $10 billion in absenteeism and direct medical costs every year.  Sixty-two million Americans get the flu each year, and around 200,000 are hospitalized.  As mentioned, anywhere between 3,000 and 30,000 will die, most of them elderly, but some young children and some chronically ill persons of any age as well.


While many children (56%) and older Americans (66%) get vaccinated, only 35% of young adults bother to do so.  Healthy People 2020 goals are to achieve 80% vaccination rates in children, 70% in young adults, and 90% of all senior citizens and healthcare workers.  The latter group is of particular interest because, left on their own, only about 67% choose to be vaccinated.  This jumps to over 90% when flu vaccination is mandated by healthcare employer policy.


Although other diseases such as Legionnaire’s or Ebola may capture the headlines from time to time, it is important to remember our wily viral enemy, influenza, and get vaccinated whether it is mandated or not.  The cost of vaccination is minimal, but the cost of influenza may be as high as death.