Should We Plan for Pandemic at All?

Question submitted via ask@mauricearamirez.com

Why should we plan for pandemic if we aren't even sure its going to happen? Is there really a potential for this to be a pandemic?

Let' set the record straight, pandemic will occur.

Almost all of our predictive models for pandemic flu are based on 1917/1918 Spanish flu (which actually originated in Kansas); the 1957/1958 pandemic and the 1968/1969 pandemic.  The 1918 Spanish flu is known in virology circles as H1:N1.  Genetic reconstruction has allowed us to isolate this virus from pathologic specimens collected in 1917 and 1918 and stored by the U.S. military and other organizations.  This means that we can now study the actual virus H1:N1 aka the Spanish flu and compare it to the current pandemic risk H5:N1 aka Avian flu.

As we all know now from the media, influenza virus mutates over time.  Small mutations are known as antigenic drift while large mutations are known and antigenic shift.  These drifts and shifts slowly change the virus from something that the human immune system can recognize and therefore protect against to something that is novel or new to the human population – a pandemic. Antigenic drift occurs every seven years while antigenic shift occurs every 13 years. When antigenic drift and antigenic shift overlap (every 7 time 13 years plus or minus 3 years), a new and novel influenza virus is created. In short, approximately every 91 years there is a virus that the human immune system has never seen before This means that every 91 years there WILL BE a pandemic. Pandemics are very consistent and we can rely on seeing this one between 2006 and 2012.  H5:N1 will act virtually the same H1:N1 did in 1917. 

In 1918 the H1:N1 strain was seen.  Like all of pandemics before, it struck with a predictable infection rate (attack rate); approximately 1 in 3.  Of these 1 in 3 on average in the population that became ill, half would need to be cared for by family or infirmaries. Of those needing assisted care, half would become seriously ill.  Half of the seriously ill would develop severe lung disease and half of those with the severe lung disease would ultimately die. 

Comments

[J]

Maurice- Your avian flu description is very clear. As someone who works with pandemic preparedness- your detailed yet manageable summary is most welcomed. Thank you kindly.