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Too Late for the Flu Vaccine?

Flu season runs from October to May, with most cases happening from late December to early March. But the flu vaccine is usually offered from September until mid-November. Getting vaccinated before the flu season is in full force gives the body a chance to build up immunity to (protection from) the virus.

Even though it's best to get vaccinated as soon as the flu vaccine is available, getting the vaccine later can still be helpful. Even as late as January, there are still a few months left in the flu season, so it's still a good idea to get protected.

Who Should Get the Flu Vaccine?

The flu vaccine is recommended for everyone age 6 months and older. It's especially important for people who are at greater risk of developing health problems from the flu to get vaccinated. They include:

  • all kids 6 months through 4 years old (babies younger than 6 months are also considered high risk, but they cannot receive the flu vaccine)
  • anyone 65 years and older
  • all women who are pregnant, are considering pregnancy, have recently given birth, or are breastfeeding during flu season
  • anyone whose immune system is weakened from medications or illnesses (like HIV infection)
  • residents of long-term care facilities, such as nursing homes
  • anyone (adults, teens, and kids) with a chronic medical condition, such as asthma
  • kids or teens who take aspirin regularly and are at risk for developing Reye syndrome if they get the flu
  • caregivers or household contacts of anyone in a high-risk group (like children younger than 5 years old, especially those younger than 6 months, and those with high-risk conditions)
  • Native Americans and Alaskan Natives

Kids under 9 years old will receive two doses this flu season if they have received fewer than two doses of flu vaccine before July 2015. This includes kids who are getting the flu vaccine for the first time. Those under 9 who have received at least two doses of flu vaccine previously (in the same or different seasons) will only need one dose. Kids older than 9 only need one dose of the vaccine.

It can take 1 to 2 weeks for the flu vaccine to become effective, so it's best to get vaccinated as soon as possible.

Types of Flu Vaccine

Different types of vaccines are available. One type (called trivalent) protects against three strains of the flu virus (usually, two types of influenza A viruses and one influenza B virus). Another (called quadrivalent) protects against four strains.

The vaccine can be given to kids in two different ways: by injection with a needle (the flu shot), or sprayed into the nostrils (nasal spray or nasal mist).

Both ways of delivering the vaccine are safe and effective, and experts don't recommend one type over the other, except for kids with certain medical conditions or pregnant women, who should not get the nasal spray.

Some vaccines are approved only for adults at this time, such as egg-free vaccines and intradermal shots, which are injected into the skin (instead of muscle) with a smaller needle.

Those Who Should Not Get the Vaccine

Certain things might prevent a person from getting the vaccine. Talk to your doctor to see if the vaccine is still recommended if your child:

  • has ever had a severe reaction to a flu vaccination
  • has Guillain-Barré syndrome (a rare condition that affects the immune system and nerves)

In the past, it was recommended that anyone with an egg allergy talk to a doctor about whether receiving the flu vaccine was safe because it is grown inside eggs. But health experts now say that the amount of egg allergen in the vaccine is so tiny that it (but not the nasal mist) is safe even for kids with a severe egg allergy. This is especially important during a severe flu season.

Still, a child with an egg allergy should get the flu shot in a doctor's office, not at a supermarket, drugstore, or other venue. And if the allergy is severe, it might need to be given in an allergist's office.

If your child is sick and has a fever, talk to your doctor about rescheduling the flu vaccine.

Are There Side Effects?

Most people do not have any side effects from the flu shot. Some have soreness or swelling at the site of the shot or mild side effects, such as headache or low-grade fever.

Some people who get the nasal spray vaccine may develop mild flu-like symptoms, including runny nose, headache, vomiting, muscle aches, and fever.

Where Can My Family Get the Vaccine?

The flu vaccine is available at:

  • many health care settings, including doctors' offices and public, employee, and university health clinics
  • some pharmacies
  • some supermarkets
  • some community groups or centers
  • some schools

If you have an HMO insurance plan, be sure to check with your primary care doctor before having your kids vaccinated outside the office, since most HMOs will pay for shots only if they're given through their plan.

The flu vaccine is covered by Medicare for senior citizens and is generally covered by insurance for people in other high-risk groups. Otherwise, the vaccine may cost anywhere from $10 to $50.

Reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: September 2015