Influenza is an acute respiratory disease, which is caused by infection of the respiratory tract by influenza viruses.
When you have full-blown influenza, you know it.
You have a fever, you have aches and pains, you have a cough, sore throat, muscle aches throughout.
You have chest pain, joint pain, not being able to get out of bed. You’re knocked down, you’re sick for ten days, you feel really, really miserable.
Influenza is a microscopic little package almost. It looks kind of like a ball.
The virus has two major surface proteins that stick out like spikes. They look, in a sense, like little lollypops and these are sort of the business end of the virus.
One protein is called Hemagglutinin.
It allows the virus to get into the cells it wants to infect and the other protein, called Neuraminidase has the opposite effect.
It allows the virus to escape as newly made viruses are being released from cells.
There are different subtypes of influenza and they’re named by the two surface proteins – Hemagglutinin and Neuraminidase – we tend to shorten that to just H and N.
Each of those proteins has its own variant, one, two, three, four and so on.
So, you can have an H1N1 flu virus or an H2N2.
So, influenza is not one virus, but really a whole group of viruses and they come in a wide variety of flavors.
There are thousands and thousands of different influenza sprays. But what makes it particularly crazy is that the influenza virus has a lot of sex.
If two different viruses infect one cell at the same time, you can create a new mixed and matched virus. And then it can mutate and recombine with other flu. So, the possibilities are, are, are virtually endless.
Unlike measles and other types of commonly known viruses that stayed exactly the same through years and decades, influenza is characterized by the ability to drift, meaning it changes a little. But every once in a while, you have a brand new virus in the sense of a pandemic.
It’s still influenza, but it’s a new kind of influenza, that’s not seasonal and has not infected humans before.
An influenza pandemic is the emergence of an influenza virus that is new. So, the impact of the virus can be much more severe. Basically, no one’s seen it before. So, you can have huge numbers of deaths.