How
viruses work
Before
preparing for the End Times, it’s necessary to understand the
ins and outs of influenza and pandemics. Bob England, Director
of the Maricopa County Health Department and former State Epidemiologist
of Arizona, explains, “there are different classes of flu virus
and then there are particular individual strains of flu within
those classes. Every year when you get your flu shot there are
three classes of flu–an influenza B virus and two influenza
A viruses: the influenza A viruses are H3N2 and H1N1.”
‘H’
and ‘N’ stand for two different proteins, hemagglutinin and
neuraminidase. “Hemagglutinin binds to a receptor on the human
cell that allows the virus to get inside you and the neuraminidase
is used when the virus is on its way out of the cell to look
for other cells to invade,” he continues.
There
are 16 different types of hemagglutinin and nine different types
of neuraminidase. “There are only specific ones that fit OK
with animal cells, but birds can catch and transmit all 16 hemagglutinins
and all nine neuraminidases–and the vast majority of these flus
don’t make birds (or humans) sick.
“Once
in a while you can get weirdo new bird viruses that can infect
people.”
One
way infection can occur is through an “antigenic shift,” a drastic
change in the structure of the virus caused by what England
refers to as “shuffling the deck.” This happens through ribonucleic
acid (RNA), the substance that codes for H and N and other parts
of the virus. Some animals can be infected by both an influenza
B and an influenza A virus–and the RNA from each will mix together.
The
problem arises when the resulting virus is able to be transmitted
from animals to humans, and then from human to human.
“They
used to think that all pandemic strains came about this way.
We think there’s more of a bird to human transmission possibility.
There have been lots of different episodes of avian influenza
infecting people if you go back 15‑20 years; they peter
out because they don’t have a characteristic that makes them
easy to spread from person to person the way flu usually does,”
England explains.
England
says that three conditions must be present for a virus to become
a pandemic: A brand new virus that we haven’t been exposed to
(hence, humans have no immunity), the virus is able to replicate
in people to make them sick, and the virus must be a virus that
can be efficiently transmitted from person to person.
“H5N1
meets two of the criteria,” he says, “but not the third.”
He
feels that there is a reason H5N1 has gotten so much attention:
“Most of those outbreaks were very brief in 1997, but over the
last few years it just keeps infecting people scattered everywhere.”
There
is, he says, a fourth variable that must be taken into consideration.
“If all three things are present you have a pandemic, but the
fourth is how virulent is that virus. Some seasons it’s really
mild, and in some seasons if it didn’t kill you, you wish it
did.”
H5N1
has a mortality rate of more than 50 percent–and that’s the
known mortality.
Two
Schools of Thought
England
describes two schools of thought when it comes to the danger
of H5N1: the first, that, “because it’s been hanging around
infecting select groups for such a long time, the greater the
possibility is that it will mutate and become able to pass from
person to person.”
The
second takes its cue from history: “Past pandemics probably
arose from single jumps to people and just took off. If this
virus has been hanging around this long and it hasn’t made the
jump yet, then maybe it can’t.”
Yes,
there will be mass human mortality.
Will
four chickens in China become our four horsemen of the apocalypse?
When
asked what we could do if a bird flu pandemic hit today, Dr.
Michael Osterholm, Director of The Center for Infectious Disease
Research and Policy (CIDRAP) was quoted as saying: “I don’t
know what we could do about it, except say, ‘We’re screwed.’’’
In
an article he wrote for the 2005 July/August issue of Foreign
Affairs, Dr. Osterholm reported the following: “Recent clinical,
epidemiological, and laboratory evidence suggests that the impact
of a pandemic caused by the current H5N1 strain would be similar
to that of the 1918‑19 pandemic.”
He
went on: “More than half of the people killed in that pandemic
were 18 to 40 years old and largely healthy. If 1918‑19
mortality data are extrapolated to the current U.S. population,
1.7 million people could die, half of them between the ages
of 18 and 40.”
Taking
those estimates to a global scale, he estimates that the virus
could “yield 180‑360 million deaths, more than five times
the cumulative number of documented AIDS deaths.”
No,
there will not be mass human mortality.
“Essentially
what we’re seeing in the Asian bird flu virus is certainly a
pandemic for birds, but not necessarily for humans,” says David
Engelthaler, State Epidemilologist of Arizona.
“The
human cases to date have been incidental and low in number,”
he reports. He points out that extreme cases occur when people
live in close contact with their poultry, something that doesn’t
happen in many Western countries.
“A
new or novel virus would come out of birds that may end up causing
a large human outbreak. Humans
don’t have immunity to this, and do become infected by it,”
Engelthaler says.
However,
he explains, the virus has to adapt to humans under all the
right conditions, with all the right possibilities of mutations.
“No one knows what those odds are, but at this point in time
the more science learns about this virus and how it does affect
humans, the less likely (it will be).”
Pandemics
occur often, and they are certainly not limited to avian influenza.
“There’s potential here, but there’s potential for viruses to
come out of any area of the world and become a pandemic,”he
says.
“I’m
not raising an alarm bell, ‘the bird flu is coming! the bird
flu is coming!’’’
“Maybe
there’s something about H5N1 that just isn’t a good match for
human cells and therefore it will never make that transmission,”
England muses. “One piece of evidence is that flu incubation
is very short (one to three days), but H5N1 has an incubation
period closer to 10 days. That’s a hint that even after people
have been exposed, it just has a hard time replicating in human
cells.”
The
Road to Prevention
Whether
the opinion is “no, we have nothing to worry about,” or “yes,
death of the human race is unavoidable,” the experts do agree
on one thing: Discussion of pandemic influenza should be used
to raise awareness of any disease‑related emergency, avian
flu or otherwise.
“The
key isn’t to figure out just what we are going to do to minimize
death. A huge chunk of it is how are we going to hold society
together,” England asserts. He looks at how the country deals
Avian Influenza as a model for any other possible outbreaks.
“The
system we have right now for producing flu vaccine is just archaic,”
England says. “We take fertile chicken eggs and then we inject
them with flu virus. And it take one egg per dose to create
a vaccine. You need hundreds of thousands of fertile chicken
eggs each day to pull off a process that starts in February
so we can start administering it the following October. And
we don’t have the capacity in this country to create enough
vaccines.”
Alan
Kraft, the Director of Environmental Health and Engineering
for Indian Health Services in Arizona echoed Engelthaler’s sentiment.
“People
who are worried about avian flu need to be worried about other
flus as well. Nationally we lose 30,000 people a year from the
flu. We do have concerns that if we go into major production
of vaccines for avian flu, it might knock the flu vaccine off
production.”
Further
complicating matters is the fact that the human body has to
experience the H1N1 and the H3N2 at least once before in order
to mount an effective immunity.
“The
first dose is a primer and the second dose is when you start
to make antibodies,” says England. “How many of us have ever
seen H5N1? We’re all going to need two doses a month apart.”
“We
have a prototype against H5N1; we just don’t know whether it
will work well at all against a particular strain after it’s
made the mutation that becomes the strain that pops out to be
a pandemic,” England says. “There are really national policy
issues here.”
He
estimates that there are only enough vaccines to vaccinate one
percent of the population a week.
England
asks a series of questions to illustrate all the aspects of
pandemic outbreaks that have not yet been discussed: “How are
we going to vaccinate priority groups? Are healthcare workers
first in line? There are 11 million healthcare workers. It will
take a month to vaccinate them. What about first responders?
What about VIPs (key leaders)? What about people important to
the infrastructure (bus drivers, utility workers, food delivery
system)? Who gets it the first week versus week number two and
three? Where does the military come in? Do we really want to
be fighting a war in Iraq and not have the troops get the vaccine
first?”
“As
we do this planning, we all have to follow the same hierarchy.
The implications for social disruption are just huge,” England
points out.
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