The CDC has spoken: It’s time to get your yearly flu shot. Because it takes two weeks to take full effect, experts recommend getting it as early as possible, since flu season begins to hit the U.S. in October.

As always, everyone six months old and over should receive the flu vaccine. Children who are being vaccinated for the first time should receive two doses for maximum protection, so make sure to tell your pediatrician if it’s your child’s first one.

By getting the vaccine in September or early October, you and your family will have the best chance to avoid the flu completely.

There are certain vulnerable groups who should take special care to get the shot. Young children (under 5), older people (over 65), pregnant women, and people with compromised immune systems are at greater risk of complications if they get the flu, which is why it’s especially important for these individuals to be vaccinated.

People who take care of others in any capacity (parents, caretakers for the elderly, or healthcare workers) should also make sure they are vaccinated to protect themselves and others.

Getting a flu shot every year is important for everyone, however, since immunity can fade over time. The flu virus is also constantly changing, so the strains of flu that are active change from year to year. This year’s flu shot will be slightly different from last, and so on.

There are several different varieties of the flu vaccine. Trivalent vaccine protects against two influenza A strains, and one influenza B strain. A high-dose version is available for people over 65. The standard vaccine is incubated in eggs, but an egg-free version is available for people between the ages of 18 and 49 with egg allergies.

Quadrivalent vaccine protects against two influenza A strains, and two influenza B strains. There is also a nasal spray version available for children and adults. It is not recommended for people with asthma, a weakened immune system, egg allergy, or those taking aspirin.

The nasal spray version may be even more effective than the shot for young children, and the CDC recommends it as the preferred method for children from two to eight years old.

Wash hands regularly with soap and warm water; sneeze or cough into the crook of your arm instead of your hand; and try not to spend time around people who have already contracted the flu.

The CDC also urges people to remember that the flu vaccine is safe and extremely effective. It protects millions of people from the flu and its complications, which can include hospitalization from a number of causes and, unfortunately, death.

You may experience mild achiness or fever after the vaccine — this is not the flu, however, and these side effects should fade within a day or two.

And, as always, remember to protect your self and your kids in other ways as well. Wash hands regularly with soap and warm water; sneeze or cough into the crook of your arm instead of your hand; and try not to spend time around people who have already contracted the flu.

If you or your family members come down with the flu, stay home from work if you can, and keep your kids home from school. Taking a fever-reducing medication and going back to work is the worst thing, since it’s a very good way to spread the flu.

Influenza is a serious illness, and you don’t want to mess around with it. Last year many people were slow to get the shot, which the CDC says is one reason why 2013-2014 was such a bad flu season. By getting the vaccine in September or early October, you and your family will have the best chance to avoid the flu completely.

For more information on the flu, visit the CDC’s flu site or www.flu.gov. And for more information on who should not get vaccinated, see http://www.cdc.gov/flu/protect/whoshouldvax.htm.