Some things to
think about in the event of a Pandemic.
This document is broken into sections. There is a short ‘Main Body’ the aim of which is to give a basic understanding of the virus & associated risks and what you may be able to do to mitigate the effects of a pandemic. The rest of the document – in fact the bulk of it – is given over to more detailed explanations and practical tips.
Some things to think about in the event of a Pandemic.
1 What is a Pandemic, how likely is
it to occur and how bad might it get?.
2 Viruses, flu and the Biology
stuff.
What medicines are available to fight this flu?
How will people react if it reaches their community?
What of the moral, legal and ethical questions?
4 If it all goes pear shaped what
can I do to protect me & mine?
Financial Prepping (Kindly supplied by Florida1 of
Flutrackers)
Sites to check for the latest situation updates
Medical Prepping & Patient Care
Appendix B –More detailed flu biology
Appendix C – The 1918 flu pandemic & other lessons
from History
Appendix D – Experts & Institutional Planning.
Who are the experts and what are they saying?
Appendix E – A Personal View & Conclusion.
What do I think is a likely scenario and what do I
recommend?
First of all DON’T PANIC! This guide is really to prepare you for a worst case scenario which hopefully won’t happen. Having said that the probability is not negligible and it is worth investing the time to try and understand the problem and at least think about how well prepared you are to cope. All the worlds’ governments are spending significant amounts of time and money preparing, however if you read on you will find that there is not that much they can realistically do beyond trying to protect what they perceive to be their key workers. You may, or may not, fall into that category and even if you do it is unlikely that all your loved ones do.
An epidemic is an illness that spreads exponentially, that is to say that if after a week 10 people are infected, two weeks 100, three weeks 1000 etc. rather than one week 10, two weeks 20, three weeks 30 etc. A pandemic is just an epidemic with global reach. Pandemics occur when a new disease, to which humans have no natural resistance, emerges and which has the ability to easily transmit from person to person e.g. HIV/AIDS. This can also be an old disease introduced to a new population, explorers inadvertently wiped out whole tribes of Amazonian Indians with what we would class as ‘childhood diseases’.
Pandemics have occurred throughout recorded history major ones being caused by Cholera, Smallpox, Bubonic Plague, Influenza and others. Wikipedia lists major pandemics in 430BC, 165AD, 541, 1300s, 1800s & 1918. Fortunately for us modern medicine has answers for many of these old killers, however viruses – like the common cold & flu – still have the upper hand. The reason for this should become clearer in section 2.
How likely is it to occur? Tricky question, the short answer is quite likely but to really answer the question you need to define ‘it’. Is ‘it’ a virulent highly infectious outbreak like the 1918 ‘Spanish flu’ or something much closer to an ordinary winter flu outbreak?
Lee Jong-wook,
(director-general of the World Health Organization) said in November 2005
"It is only a matter of time before an avian flu virus - most likely H5N1
- acquires the ability to be transmitted from human to human, sparking the
outbreak of human pandemic influenza”, while at the same meeting a World Bank
spokesman put the possible cost of such an outbreak at $800 Billion.
The WHO operates a 6 level alert scale 1
being no danger & 6 Pandemic, at the time of writing (
Figure 1 - WHO Pandemic Scale 1
Viruses mutate all of the time, within the bird population this virus changed first into a virulent form killing many of the infected birds and then again into a form that could jump the species barrier to humans. It would be a mistake to think of this as two mutations there would have been millions since the first reported case in 1996 (a goose in China) and it will continue to mutate as there seems to be little chance of eradicating from the wild bird population, some of which are asymptomatic (carriers without symptoms). The virus may continue to gradually mutate into forms which may be more easily transmitted or in the event of two different viruses infecting the same person (or other species) at the same time these virus may recombine to form hybrids with characteristics from each genetic donor. There are two competing models for influenza mutation; I favour a model including recombination but see text box for details.
Recombination vs. Shift & Drift The flu virus has 8 strands of Recombination allows for a third
option, in which the new viral strain can have half a strand from one
‘parent’ and half from the other. In fact it allows for the inserted
section to be of any length so Reassortment can be viewed as an example of
Recombination where the inserted length happened to equal the strand
length. This may appear to be a trivial
distinction but has profound implications regarding both vaccine production
and the likelihood of Pandemic emergence. See Appendix for more details
Why is there all the fuss about this flu when we get flu outbreaks every winter?
H5N1 is a form of flu in the same way as a tiger is a form of cat.
Often when someone misses work for a few
days they say they had flu, in reality many of these cases are just bad
colds. True seasonal flu is quite
debilitating and kills 0.2 to 0.3% of those that catch it, which is known as
the ‘Case Fatality Rate’. Of the confirmed cases of H5N1 over half have died
giving it a > 50%
Multiply
The 1918 H1N1 flu pandemic is thought to have killed over 50 million. In the event that H5N1 kept its current lethality and had a typical pandemic CAR it would kill about 1 billion people or 1/6th of the world’s population, that’s more people than lived on the earth in 1918 – hence the need to at least pay attention.
One definition of life is that living
things respire, that is they take in oxygen and use it to burn fuel in their
cells giving off carbon dioxide. This
definition works well for plants, animals and single celled organisms like
bacteria but by this definition viruses would not be alive. All but the viruses
have one or more cells with a nucleus containing some genetic material (usually
Avian Influenza is subdivided by the
proteins that occur in its outer coating, namely Hemagglutinin (H) and
Nuraminidase (N). There are 16 H variants and 9 type Ns giving 144 possible
combinations. Combination H5N1 is obviously causing concern now but the 20th
century influenza pandemic were caused by H1N1 (Spanish Flu 1918), H2N2 (Asian
flu 1957) & H3N2 (Hong Kong Flu 1968). H5N1 has already caused a pandemic –
in birds not humans – “Since mid-2003, this virus has caused the largest and
most severe outbreaks in poultry on record”2
. H5N1, or any flu, is further subdivided into
strains which are more minor genetic variations. For a fuller explanation of
H5N1 genetics and better understanding if its mutations see Appendix B –More detailed flu biology.
This may be a good moment to point out that the flu we are concerned about does not yet exist. Yes there are avian H5N1 strains that have infected and killed humans but it has a very limited ability to transfer from human to human in its current form and must ‘improve’ this capability before it becomes a pandemic candidate. There are two main defences against flu, anti-viral drugs and vaccines.
Anti-Virals
The anti-virals are effective against a wide range of flu viruses and the one attracting the most attention at present - and which is being used to treat current patients - is oseltamivir (sold by Roche as Tamiflu). This is a neuraminidase inhibitor (i.e. it interferes with the function of the N part of H5N1’s protein coat, so blocking the release of more virus). Oseltamivir was developed for seasonal flu and the standard treatment calls for a 5 day course to prevent viral replication. For the treatment of H5N1 patients a double dose for 10 days seems to be the best option leading to a need to quadruple the stock pile. As stocks have become available they have been bought up by the richer industrialized countries but are unlikely to cover all those infected at the higher dose, poor countries have not been able to build significant stockpiles. Unfortunately most plans do not allow for prophylactic usage; in the event of a pandemic all medical staff, and others with unavoidable exposure to infected patients, will need to take Tamiflu continuously and indefinitely which will rapidly consume stocks. A secondary effect of this environment would be strong positive selection for Tamiflu resistant mutations. It is normal to try and prevent this by combination therapy; regretfully there is no combination candidate. The other anti-virals have proved either more difficult to administer, less effective, more prone to resistance.
Pandemics tend to be made up of waves,
in 1918 the first wave came in the spring and was serious but it died down
over the summer returning in a more virulent form at the beginning of the
traditional flu season. This second wave accounted for 90% of the
fatalities (At the time the death toll was estimated at 20 million but has
been revised up and is currently thought to be 60 to 100 million). The
third wave came the following spring after which the pandemic died out.
Probably because there were not enough people left to sustain it who had
not either already had it or had natural immunity. Typically our natural
genetic diversity means about half the population seems to have a natural
immunity to any given flu virus.
Vaccines work differently; they train the body’s immune system to attack certain foreign objects. If you become ill with the flu and recover you can not then catch the same flu again, at least for a while, the effect will degrade over time. This immunity is caused by the production of anti-bodies which are simple chemical keys that ‘fit’ to the shape of the molecules on the outside of the virus. These anti-bodies circulate in the blood and if they meet the same pathogen again they bind to it ‘attracting’ a heightened immune response, so killing off the attack before it can get a foothold. All well and good but you can not make the key until you know what the lock is like and antibodies are very specific. Once the pandemic form of the virus emerges there will be furious efforts to make the vaccine. Vaccine is normally produced by infecting fertilised hens eggs with the virus, letting it develop and then heat treating the eggs to kill the virus. The inert virus proteins are then extracted ready for vaccination and our immune system makes anti-bodies just as if we had previously had that illness. As always there is a but, it takes several months to bring a vaccine into production and the only suitable plants are those that produce our current winter flu shots which are already working to capaci