Everyone knows what it is like to get the flu, but do you really know what the flu is? The flu is a sickness caused by the influenza virus. It can enter your body through your eyes, nose, mouth, or open cut, and it can cause havic on your body. The flu virus is very common and comes in three types, A that infects animals, B that infects humans, and C that infects humans, but very mildly. These three types are the cause of the flu you may have gotten this winter. Type A of the flu is also broken down into more groups. The groups go by what proteins are the virus made of. If you have ever heard a name like H1N1 or H3N2 that stands for the proteins that can be found on a virus. The H stands for hemagglutinin and the N stands for neuraminidase. The hemagglutinin is responsible for attaching the virus to one of your cells, while the neuraminidase are responsible for detaching it. Each one is followed by a number standing for a diffrent type of each protein. The H can be followed by a number 1 through 16 and the N can be followed by 1 through 9. This leaves us with a total of 144 combinations, that is 144 diffrent flus that could infect you or other animals. Not all the strains can infect humans though. The ones that have infected people are H7N7, H5N1, H9N2, H7N2, H5N1, H7N3, and H1N1. The flu though is constantly mutating, so more types of flu are possible in the future. It is hard to create a vaccine for the flu. Because it is always changing, the antibodies your body may have produced before will no longer work on a mutated virus. The smallest change to the viruses genes will cause the anitbodies that used to fight the old infection barly work or even not work at all. Near flu season a vaccine is made for what is predicted to be the most harmful virus that season, so even if you get the seasonal flu shot you still could get sick. Weve talked alot about type A influenza, but what about type B and C? Type B and C are not as dangerous as type A is and are also more common. Type A influenza found in only dangerous pandemics. Type B and C are not as wide spread and cause less seriuos symptoms. But wait, what makes one strain of the flu more dangerous than another? The answer is how fast it mutates. If the virus can quickly it can adapt faster. It can change to quickly infect another type of animal or to jump from an animal to a person. It can adapt to change its genes slightly so antibodies won't work against it. If it can change fast enough it will either run out of people to infect or will slowly decline through a few months. If you think you have the flu you should stay home form school, work, or daycare. After being exposed to the virus you may not feel sympotoms for right away, but you still can spread the sickness. You can also spread it 4 to 7 days after you are sick, so becarful even after getting the flu. Symptoms include often high fever, headache, extreme tiredness, dry cough, sore throat, runny or stuffy nose, muscle aches, nausea, vomiting, and diarrhea, but symptoms vary by the virus strain. If you can get vaccinated for the flu, you should. It is recomended by the CDC that children, pregnent women, edlerly, and people who are at a high risk for getting sick to get vaccinated. Some people belive you can get sick from a vaccine because it contains a live and wekend virus, but this is not true. If you get sick after you got vaccinated, it is because you already may have had the virus in you and you just have not yet felt the symptoms. A vaccine does not stop the virus in its tracks, but allows your body to create antibodies to fight it. Remeber only you can prevent the flu.