The H3 N2 Flu - Are We Ready For The Onslaught? What About An Avian (H5 N1) Pandemic?

Electron micrograph of the H3 N2  influenza virus.


My first introduction to the H3 N2 flu virus arrived in December, 1968, after I'd just flown home to Miami from New Orleans for the Christmas holidays.   Within 2 days of my arrival I was hit by one of the nastiest flu viruses,  called "the Hong Kong flu".   A micrograph of the virus is shown below:


I was basically laid up in bed with body aches, chills, severe nausea and fever for 8 days, and could not partake of any Christmas dinner. Since I was unable to do so, my parents decided to visit my younger brother, John, at his Naval Air base in northern Florida.  They asked if I'd be ok alone, and I assured them I could tough it out. There were plenty of cans of chicken noodle soup, as well as bread (for toast) and other assorted stuff - even some slices of spiral ham -  if I was able to consume such later.

Most of my time was spent just watching the tube, and reading - when I could. I was perhaps 90 percent better by the time I returned to New Orleans but within two days had to take extra time off from the oil company I worked at - after a relapse. (At that time, most proper companies gave employees 2 weeks sick leave, unlike the penny pinching, greedy rats today.)

We now know the arrival of the Hong Kong flu in 1968, started with a half million cases in Hong Kong. This was also the first (then known) arrival of the H3 N2 flu virus.   From Wikipedia we learn:

"The Hong Kong Flu was a category 2 flu pandemic caused by a strain of H3N2 descended from H2N2 by antigenic shift, in which genes from multiple subtypes reassorted to form a new virus. This pandemic of 1968 and 1969 killed an estimated one million people worldwide"

We also learn:

"Both the H2N2 and H3N2 pandemic flu strains contained genes from avian influenza viruses. The new subtypes arose in pigs coinfected with avian and human viruses and were soon transferred to humans. Swine were considered the original "intermediate host" for influenza, because they supported reassortment of divergent subtypes."

And:

The Hong Kong flu strain shared internal genes and the neuraminidase with the 1957 Asian flu (H2N2). Accumulated antibodies to the neuraminidase or internal proteins may have resulted in much fewer casualties than most pandemics.The Hong Kong flu was the first known outbreak of the H3N2 strain, though there is serologic evidence of H3N? infections in the late 19th century. "

This is useful to know now as the medical gurus are warning of a new onslaught and incarnation of this flu - after it literally tore through Australia during the Aussie winter. Even two months ago, because of our ages - we were warned by our PCP to not miss the flu shots this year. Not long after we each got the  quadrivalent recombinant flu vaccine, as well as the special   PCV13   pneumonia vaccine. Given severe flu can easily lead to pneumonia (and my dad died from pneumonia in 2009) this was a no brainer.

What we know already is that the the flu vaccine is only about 10 percent effective, and the quadrivalent vaccine may be slightly better. Each year matching the vaccine to the projected influenze virus to emerge is a literal crap shot, because the virus mutates so easily.. So what might have worked 8 or 9 months ago now no longer does.  Like other life forms, viruses adapt as well to external conditions and even to other flu viruses.  As noted earlier, one can have an antigenic shift, in which genes from multiple influenza subtypes reassort to form a new virus.

Professor Robert Dingwall, a public health expert at Nottingham Trent University, told the UK Daily Express it is expected to be the oncoming H3 N2 season is expected to be the most serious flu outbreak since the 1968 pandemic that started in Hong Kong and killed more than a million people world wide.

From 2003 to 2013, the three flu seasons that were dominated by H3N2 strains of the flu had the highest mortality rates - causing more deaths on average than other years (excluding the 2009 H1N1 pandemic flu).  All this is happening - with the new H3 N2 outbreak almost upon us - as we near the 100th anniversary of the Spanish Flu pandemic. This was estimated to have wiped out nearly ten percent of the global population at the time - or up to 50 million.

Coincidentally, the World Health Organization is closely monitoring a new strain of H7 N9 in China, also known as Avian flu. To be sure this is a cross species form or Avian flu and not anywhere as deadly as the H5 N1 which is keeping researchers like Pardis Sabeti of Harvard up at night.  Why? Because it holds the greatest potential for human annihilation.

In 2003, world-renowned virologist Robert G. Webster published an article titled:  "The world is teetering on the edge of a pandemic that could kill a large fraction of the human population" in American Scientist. He called for adequate resources to fight what he sees as a major world threat to possibly billions of lives. 

On September 29, 2005, David Nabarro, the newly appointed Senior United Nations System Coordinator for Avian and Human Influenza, warned the world that an outbreak of avian influenza could kill anywhere between 5 million and 150 million people. The reported mortality rate of highly pathogenic H5N1 avian influenza in a human is high; WHO data indicate 60% of cases classified as H5N1 resulted in death. My take, given the H5N1 would incept a "cytokine storm"  similar to what the H1N1 Spanish Flu did, is that at least 500 million would perish, and possibly as many as 1 billion

Electron micrograph of H5N1 influenza virus particles. 

Research on genetically restored Spanish flu discloses that death likely arrived via a cytokine storm, i.e. the victim basically "drowns" in their own lung fluids. the current Avian flu cases.  In a number of  documented Asian cases, victims with H5N1 experienced diarrhea followed rapidly by a coma without developing respiratory or flu-like symptom. This shows that one can perish that suddenly, and with no evident breathing problem.  The inflammatory cascade triggered by H5N1 has been called a 'cytokine storm' by some, because of what seems to be a positive feedback process of damage to the body resulting from immune system stimulation. H5N1 induces higher levels of cytokines than the more common flu virus types.

There have been studies of the levels of cytokines in humans infected by the H5N1 flu virus. Of particular concern is elevated levels of tumor necrosis factor-alpha, a protein associated with tissue destruction at sites of infection and increased production of other cytokines. Flu virus-induced increases in the level of cytokines is also associated with flu symptoms, including fever, chills, vomiting and headache.

Genetic sequencing of avian influenza A (H5N1) viruses from human cases in Vietnam, Thailand, and Indonesia shows resistance to the antiviral medications amantadine and rimantadine, two of the medications commonly used for treatment of influenza. This leaves only two remaining antiviral medications (oseltamivir and zanamivir) that should still be effective against currently circulating strains of H5N1 viruses.

Highly pathogenic H5N1 symptoms in people can include:


• Fever and cough

• Acute respiratory distress

• Shortness of breath/difficulty breathing

• Abdominal pain

• Diarrhea

Complications:

• Pneumonia

• Respiratory failure

• Shock

Will next year, the 100th since the Spanish Flu pandemic,  usher in a killer flu pandemic of its own? We don't know, but as Prof. Pardis Sabeti pointed out on a recent CBS Early Show health segment, the virus does keep changing, mutating - adapting. This is why she's "kept up at night"  pondering the consequences if it seized on the right confluence of factors to trigger another deadly pandemic. And the next one - possibly of H5 N1 - may also eliminate 10 percent of humans...or more.  There is little pre-existing natural immunity to H5N1 virus infection in the human population. If H5N1 viruses gain the ability for efficient and sustained transmission among humans, an influenza pandemic could result, with potentially high rates of illness and death worldwide.  Let us hope we dodge that infernal
"bullet" with Avian flu on it.