What to Avoid After a Flu Shot

The flu shot is one of the best ways to protect yourself from the flu virus, but what happens after you get vaccinated matters, too. While most people experience only mild soreness or a slight fever, certain medications, activities, or underlying health conditions could affect how well the influenza vaccine works.

For the majority, flu shot side effects are temporary. But in some cases, people develop severe allergic reactions or complications that require immediate medical attention. If you’ve had lasting pain, unusual symptoms, or a serious reaction after your flu shot, it’s important to know what’s normal and when it might be time to speak with a healthcare provider or explore your legal options.

While most people recover quickly from the flu shot, certain medications, activities, or health conditions can affect how well it works. Knowing what to avoid after vaccination can help you manage side effects and recognize when to seek medical or legal help if something goes wrong.

Flu Shot Side Effects

Mild flu shot side effects are common as the immune system works overtime to develop antibodies. Most symptoms go away on their own within a few days, but it’s important to recognize when side effects are normal and when they might signal something more serious.

Common Flu Shot Side Effects

• Arm soreness at the injection site
• Slight fever, muscle aches, and fatigue
• Mild redness or swelling around the injection site

These are signs that the body is building immunity. Drinking plenty of fluids, applying a warm compress, and getting rest can help ease discomfort.

Less Common Reactions

Some people experience flu-like symptoms, such as:

• Chills
• Headache
• Feeling sick or tired for a day or two

This does not mean the flu vaccine gave you the flu virus, the influenza vaccine contains inactive viruses that cannot cause infection.

When to Seek Medical Attention

While severe allergic reactions are rare, they require immediate medical attention. Watch for:

• Difficulty breathing
• Hives or swelling of the face and throat
• Feeling faint or dizzy
• A high fever that doesn’t go away

In certain cases, the flu shot has been linked to Guillain-Barré Syndrome (GBS), a condition that causes muscle weakness and paralysis. If you experience numbness, tingling, or weakness, contact a healthcare provider immediately.

Have an Injury?

Medications That May Affect Flu Shot Effectiveness

Certain medications can interfere with how well the flu vaccine works, affecting your immune response and reducing the protective effects of the flu shot. Some may also worsen flu shot side effects, making recovery more difficult.

Pain Relievers and Anti-Inflammatory Medications

It may be tempting to take pain relievers like ibuprofen (Advil), naproxen (Aleve), or acetaminophen (Tylenol) to ease arm soreness or a slight fever, but research suggests they could impact the immune system’s response.

• NSAIDs (nonsteroidal anti-inflammatory drugs) like ibuprofen and aspirin may suppress immune cell activity, reducing the body’s ability to develop antibodies.
• Acetaminophen can lower fever and ease muscle aches, but some studies suggest it may slightly weaken the flu vaccine’s effectiveness.

If you need relief, moderate exercise, a warm compress, or staying hydrated can help reduce pain naturally.

Steroids and Immunosuppressants

People taking steroid medications (such as prednisone) or immunosuppressive drugs should consult their healthcare provider before getting a flu vaccination. These medications can:

• Weaken the immune system, making it harder for the flu vaccine to work.
• Reduce the body’s ability to develop protective effects against influenza viruses.

Biologics and Chemotherapy

If you take biologic medications for autoimmune conditions or are undergoing chemotherapy, your immune response to the flu vaccine may not be as strong. Speak with your doctor’s office about the best timing for vaccination to maximize its effectiveness.

Tips for Managing Flu Shot Side Effects

Most flu shot side effects are mild and go away within a few days, but there are ways to reduce discomfort and help your immune system recover.

Ease Pain and Soreness

• Apply a warm compress to the injection site to reduce pain and improve blood flow.
• Move your arm gently to prevent stiffness and help reduce soreness.
• Avoid sleeping on the vaccinated arm if it feels tender.

Support Your Immune System

• Drink plenty of fluids to stay hydrated and help the body recover.
• Eat lean proteins, fruits, and vegetables to give your immune system the nutrients it needs.
• Get rest if you feel tired, pushing through fatigue can make side effects worse.

When to Rest & Take It Easy

• Moderate exercise is fine, but avoid strenuous workouts if you’re feeling sick or sore.
• If you experience a slight fever, muscle aches, or chills, listen to your body and take time to recover.
• Postpone non-essential tasks if you’re not feeling well, your body needs energy to develop protective effects from the flu vaccine.

When to Call a Doctor

Most people recover without issues, but seek medical attention if:

• Side effects last longer than a few days or seem to get worse.
• You experience difficulty breathing, hives, or severe swelling (signs of a severe allergic reaction).
• A high fever doesn’t go away or is accompanied by extreme fatigue or dizziness.

Get Help Today

Can You Still Get the Flu After a Flu Shot?

Yes, it’s possible to catch the flu virus even after getting a flu shot. The influenza vaccine helps protect against the most common strains, but no vaccine is 100% effective. It takes about two weeks for the body to develop antibodies, so if you were exposed to the flu virus shortly before or after vaccination, you may still get sick.

Even if you do get the flu, the flu vaccine can still provide protective effects by reducing the severity of symptoms and lowering the risk of severe illness or complications. People who are vaccinated tend to recover faster and are less likely to require hospitalization compared to those who are unvaccinated.

Some people mistake flu shot side effects for the flu itself. Symptoms like arm soreness, a slight fever, and muscle aches are signs that the immune system is building protection, not that the vaccine has caused an infection. The flu shot contains inactive viruses, meaning it cannot cause the flu. However, the nasal spray vaccine does contain weakened flu viruses and may cause mild flu-like symptoms in some people.

Who Should Take Extra Precautions?

Most people recover quickly from a flu shot, but some should be extra cautious about side effects and how their immune system responds. Older adults, pregnant individuals, and those with chronic conditions may experience a weaker immune response, making it important to monitor symptoms closely.

People who should take extra precautions include:

• Those with weakened immune systems – If you’re undergoing chemotherapy, taking immunosuppressive medications, or living with HIV/AIDS, the flu vaccine may not be as effective. Talk to a healthcare provider about timing and whether a higher-dose flu vaccine is needed.
• Individuals with severe allergies – Some flu vaccines contain trace amounts of egg protein, which may cause reactions in people with severe egg allergies. However, most people with mild allergies can still safely receive a flu vaccination.
• Pregnant individuals – The flu virus can lead to severe illness during pregnancy, so getting vaccinated is important. Discuss any concerns with your healthcare provider to guarantee the right vaccine choice.
• People with a history of severe flu shot reactions – If you’ve had a severe allergic reaction to a past flu shot, speak with your doctor’s office before getting vaccinated again.

Work With Us At No Cost

When to Seek Legal Advice for Flu Shot Injuries

For most, flu shot side effects are mild and temporary. But in rare cases, a reaction can lead to serious complications, such as Guillain-Barré Syndrome (GBS), severe allergic reactions, or long-term nerve damage. While symptoms like arm soreness, fatigue, and a slight fever are expected, persistent pain, unexplained weakness, or worsening symptoms may indicate something more serious.

The National Vaccine Injury Compensation Program (VICP) provides financial support for individuals who experience severe vaccine-related injuries. If side effects don’t resolve, worsen over time, or impact daily life, it may be important to understand your legal options and what steps to take next.

Take Control of Your Injury Today