A topical science lesson

I was trying to determine if I had anything interesting or relevant to talk about in this blog and I chose swine flu for a few reasons.

a)I read up on it every day as

b) I do like the risk of a good old fashioned plague/apocalypse

c)it is a chance to teach you some basic bits and pieces of the sciencey stuff I love so much (apologies if you find it terribly and insultingly dumbed down or way above your head, I have been immersed in it all for too long and can’t remember what’s common understanding and what’s not.)

Stats on swine flu

As of today the WHO (World Health Organisation)reports that 985 people have been infected with influenza A(H1N1). This is the technical term for the disease the media has dubbed “swine flu”

590 of those infected have been in Mexico. In total 20 countries have shown infection and in the UK the number of those infected is 27. Today, the only reported deaths from the infection are in Mexico and a baby in America.

More about ‘Flu

Seasonal influenza is the term for the type of flu that we normally get in the winter months. During the winter when we stay inside more the close proximity, lack of fresh circulating air and dampness help the virus survive outside of the body for longer, and this means that more people get infected. Worldwide seasonal ‘flu causes 3-5million cases of severe illness each year and kills around 250-500,000 people.

Every year projections are made about the type of ‘flu viruses that are believed to be the most prevalent in both the northern and southern hemispheres and vaccines are made that protect against a few of those strains for each. The vaccines are given to those at the most risk of death, in particular:

-the elderly-whose immune systems are no longer as strong as they used to be,

-babies-who do not have properly developed immune systems and

-asthmatics-as influenza infects the respiratory system (i.e. lungs)

How does a vaccine work?

The hands represent the antibodies. The fingerprints on each hand are very subtly different and unique.

The Influenza virus particle is unique in the same way, but instead of fingerprints it has neuraminidase (N) and hemagglutanin (H) proteins on the surface. In Swine flu (H1N1) an antibody with fingerprints that perfectly match the surface of virus particle is needed if the two are to bind. It must be a perfect match and for this reason antibodies against one virus do not protect against another in most cases. When the antibody is bound the portion that we are imagining like a wrist acts as a flag. Other immune cells come and use the flag as a target and destroy the infected cell to which the antibody is bound. The immune system sacrifices the infected cell for the greater good. Virus particles that are in our systems but have not infected cells yet can also be bound by antibodies which neutralise them and stop them from infecting cells. So by a process of neutralisation and by targeting the immune cells to kill infected cells, antibodies help fight an infection. In our blood we do not have lots of the same type of antibody circulating unless we have had an infection. In the same way that the number of people in the army is increased during a war, the number of antibodies only increase in response to invasion by a virus. If an antibody recognises something it tells the body to increase its numbers. This way the body produces a select team perfect for fighting this infection. A vaccine uses either an inactivated virus (killed so that its contents are missing or dead- like a corpse it looks like it did while alive but cant do any of the same things) or just the neuraminidase or hemagglutanin proteins to trick the immune system into thinking it is infected with that specific virus. This makes it increase the amount of antibodies specific for the virus, a process which takes about 7 days. If the person is then infected with the virus they already have the antibodies and so do not have to spend around a week being infected while they wait for their immune system to catch up; they are already protected.

What is a ‘flu pandemic?

‘flu viruses do not only infect humans. Influenza A can also infect domestic animals like pigs, horses, chickens, ducks and also some wild birds. As we talked about the H and the N particles on the surface of flu virions are the bits that make each flu virus unique. Once we have seen a flu virus we are protected against it as we recognise its H and N particles.

In some instances birds or pigs have been shown to become infected with more than one type of ‘flu viruses. The H and N particles of the different viruses can get mixed up and produce a new type of virus that the immune system now doesn’t recognise e.g. H5N1 (bird flu) or H1N1 (swine flu). As this virus appears completely new on the outside out bodies do not recognise it and as such we have no immunity. This can lead to each individual who comes into contact with it getting infected and if it passes well from human-human a pandemic can occur.(a pandemic is a worldwide epidemic)

Swine flu so far has not shown that it passes very easily from human-human. This is why we haven’t seen millions of cases. In 1918 spanish flu (another type of H1N1 virus distinct from this type) was shown to pass very well from human to human and ended up killing an estimated 50 million people worldwide. More than the first world war had killed. There have been two other major pandemics since then, Asian flu in 1957 and Hong Kong flu in 1968.

Swine flu so far doesn’t appear to be as savage as either those strains or bird flu. People in this country are already recovering and it has been described as being more like “seasonal flu” which, although can be deadly, is something more like the infections we normally see.

Swine flu vaccine

The WHO reckons it will take around 6 months to get a vaccine properly developed. When it is produced they think they can ensure 1-2 billion doses are made each year. 90% of the global capacity for making the vaccine is in Europe and North America (although this doesn’t mean we’d get to keep it all).

The vaccine would most likely be given to the at risk groups although who that is as yet is currently hard to determine. Another problem is that the virus might mutate to a more dangerous form that the vaccine doesn’t protect against. If this happens we still have antiviral drugs which can help. These are like the virus version of antibiotics (which kill bacteria). The UK is the most prepared country in the world for bird flu and have lots of Tamiflu stockpiled. Lucky for us Tamiflu can also be used to treat swine flu. Good eh?

How to avoid getting swine flu

The WHO suggests avoiding those who look feverish or ill. This is common sense and is probably best applied all the time.

If you know someone has swine flu, again best to treat them like a leper.

The WHO isn’t suggesting restricting travel (but this is probably for political reasons) they do however suggest avoiding people who have swine flu, and as most of the swine flu is in Mexico….well, it’s pretty obvious where I won’t be choosing to go on holiday.

Try not to hang out with pigs too often.

However it is important to note that you CANNOT get swine flu from properly cooked pork or pork products. The price of this meat will probably go down in supermarkets while silly people who do not know this fact avoid the meat all together, so beat the credit crunch and stock up on pig meat.(Do remember to cook it properly, not just to make sure there is definitely no ‘flu but also because no one likes worms)

Wash your hands every few hours, you only need some snotty person to start shaking hands with you and then for you to touch your nose etc to increase your risk of infection.

You could try wearing a face mask but most transmission of ‘flu only occurs when a person is showing symptoms, so unless you are around someone who is infected you just look like an idiot for no good reason.

Throw away tissues and facemasks properly. Flinging them into the face of the nearest baby isn’t really an option.

The WHO also suggests getting plenty of sleep, eating healthily and avoiding things damaging to health (probably alcohol and cigarettes). This is probably all a cunning ruse to make us get healthy.

So, are we all going to die?

Probably not at the moment. Just in case though, avoid people who look ill and stay clean!

(I will keep you updated if this all changes)