Influenza, commonly called the flu, is a contagious respiratory illness that can cause symptoms ranging from fever and body aches to more serious complications. While many people recover at home, influenza can cause severe illness, particularly among young children, older adults, pregnant people, and individuals with certain chronic medical conditions.
One of the most important ways to reduce the risk of seasonal influenza and its complications is an annual flu vaccination. Because influenza viruses change over time and protection from vaccination decreases, flu vaccines are updated and recommended each flu season.
At iCare ER & Urgent Care, we provide care for patients experiencing flu symptoms and other respiratory illnesses, and flu shots are among the preventive services available through urgent care. Understanding who should receive a flu vaccine, when to get vaccinated, and what to expect afterward can help you prepare for flu season.
What Is the Flu Vaccine?
The flu vaccine is designed to help your immune system recognize and respond to influenza viruses.
Seasonal influenza vaccines are updated to protect against influenza viruses expected to circulate during the upcoming flu season. Because circulating strains can change and immune protection decreases over time, getting vaccinated during a previous flu season does not replace the need for the current season’s vaccine.
Flu vaccination cannot guarantee that you will not get influenza. However, vaccination can reduce your likelihood of becoming sick and can reduce the severity of illness in people who become infected despite being vaccinated.
It is important to remember that influenza is different from the common cold and other respiratory illnesses. A flu vaccine specifically targets influenza viruses and does not prevent every illness that can cause coughing, congestion, or fever.
Who Should Get a Flu Shot?
Annual influenza vaccination is recommended for most people 6 months of age and older, with rare exceptions.
That broad recommendation includes:
- Children
- Teenagers
- Adults
- Older adults
- Pregnant people
- People with many chronic medical conditions
The specific vaccine that is appropriate can depend on a person’s age, health history, allergies, and other individual factors.
If you have questions about whether a particular influenza vaccine is appropriate for you or your child, talk with a healthcare professional.
Why Are Flu Shots Needed Every Year?
Unlike some vaccines that may provide long-lasting protection after a completed series, influenza vaccination is recommended annually.
There are two major reasons.
First, influenza viruses continually change. The vaccines available each season are formulated to target influenza viruses expected to be most relevant during that season.
Second, immune protection from vaccination decreases over time.
Getting the current seasonal vaccine helps provide updated protection rather than relying on a flu shot received during a previous year.
When Is the Best Time to Get a Flu Shot?
For most people who need only one flu vaccine dose during the season, September or October is generally a good time to be vaccinated.
Ideally, vaccination should occur before influenza is widely circulating in the community, but getting vaccinated too early may result in reduced protection later in the season.
There are some important exceptions. Certain children who need two doses during a flu season may need to begin vaccination earlier so there is enough time between doses. Timing during pregnancy and for some older adults can also involve individual considerations.
If you miss the early fall vaccination window, that does not necessarily mean it is too late. Flu vaccination can continue to provide value while influenza viruses are circulating.
How Long Does a Flu Shot Take to Work?
Your body does not develop its full immune response immediately after vaccination.
It generally takes about two weeks for antibodies to develop after receiving a flu vaccine. This is one reason vaccination is recommended before influenza activity becomes widespread whenever possible.
During that period, it is still possible to become infected with influenza.
Someone who develops flu symptoms shortly after vaccination may have been exposed before protection had time to develop. They may also have another respiratory infection with similar symptoms.
Can the Flu Shot Give You the Flu?
A flu shot cannot cause influenza.
Injected flu vaccines do not contain infectious influenza virus capable of causing the flu. Some vaccines contain inactivated virus, while others use only specific components of the virus to trigger an immune response.
It is possible to experience mild side effects after vaccination, such as soreness or fatigue. These symptoms are related to the body’s immune response and are not the same as developing influenza.
It is also possible to become sick with an unrelated respiratory virus around the same time as receiving a flu shot, which can sometimes lead people to incorrectly associate the illness with vaccination.
What Should You Expect When Getting a Flu Shot?
Getting a flu shot is generally quick.
Before vaccination, a healthcare professional may ask about:
- Your age
- Previous reactions to vaccines
- Allergies
- Current illness
- Medical history
- Pregnancy, when relevant
The vaccine is typically administered into the muscle of the upper arm. Younger children may receive an injection in a different location based on age.
Afterward, you may be advised to remain briefly for observation, particularly if there are concerns about allergic reactions.
Most people can return to their normal activities after receiving a flu shot.
Common Flu Shot Side Effects
Most flu vaccine side effects are mild and resolve without treatment.
Common reactions can include:
- Pain or tenderness at the injection site
- Redness or mild swelling
- Headache
- Fatigue
- Muscle aches
- Low-grade fever
These symptoms usually indicate that the immune system is responding to the vaccine.
A cool compress may help with soreness at the injection site. Rest and fluids can also be helpful if you feel tired or mildly unwell.
Contact a healthcare professional if you have concerns about symptoms following vaccination.
When Is a Reaction to a Flu Shot an Emergency?
Severe allergic reactions to vaccines are rare, but they require immediate medical attention.
Call 911 for symptoms of a severe allergic reaction, including:
- Difficulty breathing
- Swelling of the face or throat
- Widespread hives accompanied by breathing problems
- Severe weakness or collapse
- Dizziness or loss of consciousness associated with other signs of a serious reaction
These symptoms can indicate anaphylaxis, which requires emergency treatment.
Emergency Disclaimer: If you or someone else is experiencing severe difficulty breathing, swelling of the face or throat, loss of consciousness, or another potentially life-threatening reaction after vaccination, call 911 immediately. This article is for general educational purposes and is not a substitute for emergency medical evaluation, diagnosis, or treatment.
Flu Vaccines for Children
Influenza can cause significant illness in children, making annual vaccination an important preventive measure for most children 6 months and older.
Depending on age and vaccination history, some children between 6 months and 8 years old may need two doses of influenza vaccine during a single season. When two doses are necessary, they are given at least four weeks apart.
Parents should discuss their child’s vaccination history with a healthcare provider to determine how many doses are appropriate.
Children younger than 6 months are too young to receive a flu vaccine. Vaccination of pregnant people and other household members can help reduce opportunities for influenza exposure around young infants.
Flu Vaccines During Pregnancy
Flu vaccination is recommended during pregnancy because pregnancy can increase the risk of serious complications from influenza.
An injectable influenza vaccine can be given during any trimester of pregnancy.
Vaccination during pregnancy also provides antibodies that can help protect the baby during the first months of life, before the infant is old enough to receive a flu vaccine.
Pregnant patients with questions about vaccination should discuss them with their healthcare provider.
Flu Vaccination for Older Adults
Adults 65 and older have a higher risk of serious complications from influenza.
For this age group, certain flu vaccines are preferentially recommended when available because they are designed to produce a stronger immune response.
If a preferred vaccine is not available, older adults generally should not delay vaccination simply to wait for a particular product. A healthcare professional can help determine which available option is appropriate.
Flu Shots and Chronic Medical Conditions
Influenza can be particularly concerning for people with certain chronic health conditions.
These may include people living with:
- Asthma
- Diabetes
- Heart disease
- Chronic lung disease
- Kidney disease
- Conditions that affect the immune system
Respiratory infections can sometimes worsen underlying medical conditions, making prevention especially important for higher-risk patients.
People with chronic conditions should discuss vaccine selection and timing with their healthcare provider when they have questions or specific medical concerns.
Should You Get a Flu Shot If You’re Sick?
Having a minor illness does not always mean vaccination needs to be postponed.
For example, someone with mild cold symptoms may still be able to receive a flu vaccine. However, people who are moderately or severely ill may be advised to wait until they have recovered.
The decision depends on the severity of the illness and the person’s overall condition.
If you arrive for vaccination while feeling sick, tell the healthcare professional about your symptoms before receiving the vaccine.
Flu Shot vs. Flu Treatment
A flu vaccine is preventive. It is not a treatment for an active influenza infection.
If you already have the flu, getting vaccinated will not make the current infection disappear.
Flu symptoms commonly include:
- Fever or chills
- Cough
- Sore throat
- Body aches
- Headache
- Fatigue
- Runny or stuffy nose
Some people may also experience vomiting or diarrhea, particularly children.
If symptoms develop, treatment depends on their severity, duration, risk factors, and whether complications are suspected.
When to Visit Urgent Care for Flu Symptoms
Urgent care can be appropriate for flu symptoms when the patient is stable but needs medical evaluation.
Consider urgent care for:
- Persistent fever
- Significant cough
- Sore throat
- Body aches
- Flu-like symptoms that are not improving
- Concerns about dehydration without severe symptoms
- Flu symptoms in someone at increased risk of complications
A healthcare provider can evaluate whether symptoms are consistent with influenza or another respiratory illness and determine whether testing or treatment may be appropriate.
When Flu Symptoms Require Emergency Care
Some influenza infections can lead to serious complications, including pneumonia or worsening of underlying medical conditions.
Seek emergency medical attention for concerning symptoms such as:
- Severe difficulty breathing
- Persistent chest pain or pressure
- Blue or gray lips or face
- Severe dehydration
- Confusion
- Difficulty waking
- Seizures
- Severe weakness or instability
Children may show additional warning signs, including difficulty breathing, significant dehydration, poor responsiveness, or symptoms that improve and then suddenly worsen.
Call 911 for life-threatening breathing problems, loss of consciousness, or other immediately dangerous symptoms.
Ways to Reduce the Spread of Influenza
Vaccination is an important preventive tool, but everyday habits can also help reduce the spread of respiratory viruses.
Helpful measures include:
- Wash hands regularly.
- Cover coughs and sneezes.
- Avoid close contact with others when sick.
- Avoid touching your eyes, nose, and mouth with unwashed hands.
- Clean frequently touched surfaces when someone in the household is sick.
- Stay home when you are ill when possible.
Parents can also teach children good handwashing and respiratory hygiene habits.
iCare ER & Urgent Care: Flu Shots and Flu Care
Preparing for flu season can include getting vaccinated and knowing where to seek care if influenza symptoms develop.
At iCare ER & Urgent Care, flu shots are available through urgent care, and our medical team can also evaluate adults and children experiencing flu symptoms and other respiratory illnesses.
With locations in Frisco, Forney, and Fort Worth, patients have access to both urgent care and emergency services depending on the severity of their symptoms.
Urgent care is available for non-life-threatening illnesses and preventive services, while emergency care is available 24 hours a day, 7 days a week for serious medical concerns.
Frequently Asked Questions
Who should get a flu shot?
Annual influenza vaccination is recommended for most people 6 months of age and older, with rare exceptions. The appropriate vaccine can vary based on age, medical history, pregnancy, allergies, and other factors.
What month should I get my flu shot?
September and October are generally good times for most people who need one dose during the season. However, vaccination later in the season can still be beneficial while influenza viruses continue circulating.
How long does it take for a flu vaccine to work?
It takes approximately two weeks for the body to develop antibodies following vaccination. You can still become infected with influenza during that period.
Can you get the flu from a flu shot?
No. Injectable flu vaccines cannot cause influenza. Mild soreness, fatigue, muscle aches, or low-grade fever can occur after vaccination, but these are not the same as having the flu.
Should children get a flu vaccine every year?
Most children 6 months and older should receive seasonal influenza vaccination each year. Some children between 6 months and 8 years may require two doses depending on their previous vaccination history.
Conclusion
Getting a seasonal flu vaccine is one of the primary ways to reduce the risk of influenza and its potential complications. Annual vaccination is recommended for most people 6 months and older, including children, adults, older adults, and pregnant people.
For most people, September or October is an appropriate time to receive the vaccine, but vaccination can remain beneficial later in the flu season. Side effects are generally mild, and the injected flu vaccine cannot give you influenza.
At iCare ER & Urgent Care, patients in Frisco, Forney, and Fort Worth can receive flu shots through urgent care and seek evaluation when flu symptoms require medical attention. If influenza causes severe breathing problems, chest pain, confusion, loss of consciousness, or other serious symptoms, seek emergency care immediately.