The flu virus causes epidemics because so many people are infected at one time.
Flu is always caused a virus, not bacteria, so no flu epidemic will be due to a bacterial agent. This is true of the 1918 "Spanish Flu", it was caused by a virus.
virus, epidemic, cold, the flu
Viral diseases are most likely to cause epidemics. The recent H1N1 flu virus is one example of this. One other major epidemic, which is not of infectious disease origin, is the obesity epidemic in the U.S.
Avian Flu is caused by the virus like Flu virus in man. This virus has evolved with birds.
A flu epidemic is when a lot of people get the flu in a large area.
The flu epidemic.
Influenza is caused by a virus. its straight up a virus...
the most dangerous flu on Earth is h5n1 the bird flu it kills 60% of the people it infects. This virus mutated from a virus that could only affect birds, H5n1 is an epidemic across asia. The h1n1 flu is the next most dangerous flu. In the United States it's become an epidemic. The Swine flu h1n1 does not have a high death rate and this virus mutated from a virus that only affected swine or pigs. Most people that get h1n1 flu don't die, but without proper treatment it can start to kill you within 2 days. Swine flew symptoms are same as normal flew but more severe.
The Swine Flu epidemic hit the United Kingdom in 2009. This strain was the H1N1 virus; previous influenza types had hit the world since 1918.
Short answer: No — you cannot get the flu from the flu shot. Not possible. Zero percent. ✅ Why you can’t get the flu from the flu shot The flu shot contains inactivated (killed) virus, which means: It cannot infect you It cannot multiply in your body It cannot cause the influenza illness So medically, the flu shot cannot give you the flu. ✅ Then why do some people feel sick afterward? A few normal, harmless reactions can happen as your immune system responds: Mild fever Your immune system becomes active → leads to a low-grade fever in some people. Fatigue or body aches This is a side effect, not the flu itself. Sore arm Very common due to the immune response at the injection site. You were already exposed before the shot If someone gets sick right after the vaccine, it’s often because: They were exposed to the virus a few days before the shot They caught a different virus (cold, RSV, COVID) It takes 2 weeks for the flu shot to give full protection ❗ Important note The nasal spray flu vaccine (FluMist) does contain a live-attenuated virus, but it’s weakened so much that it also cannot cause actual influenza. It may cause: Runny nose Cough Mild symptoms But not true flu illness. ✅ Bottom Line No — the flu shot does not and cannot give you the flu. You may feel mild symptoms as your immune system builds protection, but that’s a normal response — not an infection.
hmm. could be that no one knew why the flu kept getting stronger and more advanced
Flu viruses cause disease, they cause influenza (flu). They are the infectious agents of the flu. The viruses are submicroscopic organisms that infect your body and that give you the influenza, the disease.