It may still be hot outside, but flu season is around the corner. And The FDA has just approved the 2010-11 flu vaccines.

This year, the Center for Disease Control and Prevention (CDC) recommends that everyone six months of age and older get vaccinated as soon as the vaccine is available.

The best time to get the vaccine is in the fall before flu viruses start to circulate. If that's not possible, getting it later on will still provide protection.

In 2009, people had to take two different flu vaccines, because the H1N1 virus emerged after the flu vaccines were prepared. This year, it's expected that only a single vaccination will be necessary.

According to the CDC, between 5% and 20% of the U.S. population develops influenza each year, leading to more than 200,000 hospitalizations and around 36,000 deaths. The best way to protect against catching the flu is to get a yearly flu vaccination.

Flu vaccines are made by several different companies, but they all protect against the same strains of flu virus. Some vaccines contain inactivated or killed virus and are given by an injection in the arm. Others contain weakened virus and are given as a nasal spray. Neither type of vaccine will cause the flu.

In 2009, people had to take two different flu vaccines, because the H1N1 virus emerged after the flu vaccines were prepared. This year, it's expected that only a single vaccination will be necessary.

Each year, experts from FDA, World Health Organization, CDC and other institutions study virus samples and patterns collected worldwide to identify strains likely to cause the most illness during the upcoming season. The flu strains included in the U.S. vaccine are chosen from this information.

Some years, the exact viruses circulating during flu season turn out to be different from those in the vaccine. Even then, the vaccine often provides partial protection and may lead to milder illnesses in those who do catch the flu.

This year's vaccine contains three flu strains: the H1N1 strain responsible for the 2009 pandemic, a second type A influenza strain (H3N2, Perth 2009-like) and an influenza B strain (Brisbane, 2008-like).

Despite some problems with the flu vaccine Afluria® when it was introduced in the Southern Hemisphere (where it has been winter), it will be marketed in the U.S. this year.

In Australia and New Zealand Afluria® caused a higher-than-expected incidence of fever and febrile seizures in children five years of age and younger. Investigations of these events are still ongoing. Febrile seizures usually only last for a minute or two. While they can be quite frightening, they are usually harmless. Afluria®'s labeling has been changed to reflect these events and the 0.25 ml single dose version of Afluria® , which was used in very young children, will not be used at all in the U.S. this year.

The FDA announced the upcoming 2010-11 flu vaccines in a press release on July 30, 2010. The FDA website also has a Question and Answer Section that provides more information about the 2010-11 flu vaccine, Afluria® and flu vaccines in general