The best way to prevent or lessen the severity of the flu is to get a flu shot each fall. However, because the particular flu strains that the vaccine protects against may not be the same ones that are going around your area, the vaccine is not always 100% effective.
Types of Flu Vaccines
There are two types of flu vaccines:
The “flu shot” — which is given with a needle, usually in the arm, is an inactivated (or killed) vaccine
The nasal flu spray vaccine (sometimes referred to as LAIV for “Live Attenuated Influenza Vaccine”) — which is a spray taken in the nose — is an attenuated (or weakened) vaccine
Scientists make different flu vaccines every year because the strains of influenza viruses change from year to year. Nine to 10 months before the flu season begins, they prepare a new vaccine made from inactivated (killed) influenza viruses. Because the viruses have been killed, they cannot cause infection. The flu vaccine preparation is based on the strains of the flu viruses that are in circulation at the time. It includes those influenza type A and influenza type B viruses expected to circulate the following winter.
Sometimes an unpredicted new strain may appear after the vaccine has been made and distributed to doctor’s offices and clinics. Because of this, even if you do get the flu vaccine, you still may get infected.
Children 8 years old and younger who are receiving the influenza vaccine for the first time should receive 2 doses (separated by at least 4 weeks for trivalent inactivated vaccine [TIV] and at least 6 weeks for LAIV).
Flu Shot Side Effects
As with other vaccines, there are possible side effects to be aware of. The most common side effect in children and adults is soreness at the site of the vaccination. Other flu shot side effects — especially in children who have never been exposed to the flu virus — include fever, tiredness, and sore muscles. These side effects may begin 6 to 12 hours after vaccination and may last for up to 2 days.
Additionally, you should be aware that viruses for producing the vaccine are grown in chicken eggs and then killed with a chemical so they can no longer cause an infection. The flu vaccine may contain some egg protein, which can cause an allergic reaction. If you or a family member is allergic to eggs or have ever had a serious allergic reaction to the flu vaccine, consult with your health care provider before getting vaccinated.
It’s important to know all your treatment options, such as antivirals, so you can be better prepared if you get the flu.
Think You Have the Flu? What Are Flu Symptoms? Know the FACTS
Flu symptoms can be mild or severe — and if they’re mild can become severe without much notice. Be aware of your body and monitor your body temperature. Flu symptoms can come on suddenly — be sure you know your treatment and prevention options so you can be prepared.
The common symptoms of the flu include:
Fever (usually high)
Runny nose may also occur but is more common in children than adults
Stomach symptoms, such as nausea, vomiting, and diarrhea, may also occur but are more common in children than adults
You don’t need to experience all of these symptoms to have the flu. If you have one or two, it's recommended that you see your doctor. We've prepared a list of helpful questions to ask your doctor to help you make the most of your visit.