Anybody who has ever had the flu can tell you it is no picnic, and in some situations it can happen to be life-threatening.

Medical professionals want to protect society against such a sickness, so there is little case against flu shots. Every year, almost 40,000 people die of flu in the U.S. alone. Flu cases also cause about 200,000 hospitalizations, not counting the many more that stay at home sick.

Two kinds of flu vaccines exist. The traditional vaccine, which we know as the flu shot, is classified as an inactivated vaccine. Inactive vaccines contain a virus which is not alive; it is typically administered via a hypodermic needle. Flu shots can be given to anyone over six months of age in reasonable health.

The other type of vaccine is called a Live Attenuated Influenza Vaccine (LAIV). LAIVs contain weakened, live viruses. The Attenuated flu shot is administered by nasal-spray; it is only approved for use in healthy people between the age of 5 and 49.

The flu shot and the flu nasal-spray vaccine both work to develop the body's antibody defenses against the influenza strain. Antibodies are exposed to the virus in the vaccines; the antibodies then specialize themselves to attacking the invading flu. As a result, the antibodies become efficient fighting machines, lying in wait for future attacks of that influenza strain.

People are recommended by medical professionals to get a flu vaccine at least once a year. For those living in North America, the flu season generally lasts from November to April. Most people get the virus during this period, which means infections within the general populace are at its height.

Flu vaccines don't work immediately, so it is recommended that the flu vaccine is taken prior to November.

Antibodies take two weeks minimum to improve their power against a flu virus; meanwhile the individual remains at risk from the illness.

Getting vaccinated during the months of September, October, and November is a good idea because of this.

Don't forget flu viruses mutate each year, so to prevent the flu, you need to get a shot of the latest vaccine at least once a year.