What to avoid after the flu shot

As summer changes to fall, your doctor’s office and pharmacy begin offering seasonal flu shots. The Centers for Disease Control and Prevention (CDC) recommend that everyone older than six months get an annual flu vaccination during flu season—unless they have a health condition that prevents them from getting it. That means before the end of October you should be heading in for a jab.

If you catch the flu, you could be in for unpleasant symptoms like fever, chills, nausea, vomiting, muscle aches, and respiratory symptoms that can last for weeks and be quite severe. Some people are at high risk for complications, severe illness, and even hospitalizations—including the very young, the elderly, pregnant women, and people with certain medical conditions. The flu illness kills people every year, so protecting yourself and vulnerable members of your community is important. Just keep in mind that the flu shot has some mild side effects and there are a few recommendations for what to avoid after your flu shot. 

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Flu shot side effects

Most people experience a few common side effects after a flu vaccine. These are nothing to worry about and usually go away on their own after a day or so. Common reactions include:

• Site reactions like soreness at the injection site 
• Headache
• Fever
• Nausea
• Muscle aches
• Fatigue

“Feeling a little tired after getting a flu shot is normal. This is because your body works hard to build immunity to the virus,” says Alice Williams, MD, a physician in New Mexico. Mild side effects are just a sign that your body is creating an immune response and building antibodies to protect you from infection. In other words, they mean the flu shot is working.

There are, however, some serious side effects of the flu shot that you should not ignore. Serious side effects of the flu shot include:

• Fainting
• Difficulty breathing
• Shoulder injury at the injection site
• Allergic reaction
• Severe weakness, which can be a sign of Guillain-Barré syndrome 

If you think you’re having an allergic reaction, you may have hives, swelling, trouble breathing, or a rash. Call 911 or seek medical attention immediately.

What to avoid after a flu shot

Generally, if you feel well, you can continue living your life as usual after your flu shot. “There are no activity restrictions after a flu shot,” says Pierrette Mimi Poinsett, MD, a pediatrician and medical consultant at Mom Loves Best. However, there are a couple considerations to keep in mind that will ensure that your seasonal influenza vaccine is most effective and that you feel well in the days following your shot. 

1. Activities that stress your body

“It’s important to avoid activities that will put your body under stress,” Dr. Williams says. “After getting a flu shot, taking care of yourself will help ensure you stay healthy and avoid complications.” That means minimizing emotional stress, avoiding overly strenuous workouts, and making time for some rest and relaxation. 

It’s possible you won’t actually feel too tired, though, and if that’s the case, you don’t need to significantly alter your daily activities. Dr. Poinsett says that while you might feel tired for a day or two after your flu shot, “There is no need to rest after a flu shot unless you feel tired.” 

Exercise after a vaccine is not expressly forbidden by healthcare professionals. However, you’ll want to judge your own personal comfort level when thinking about if or how much exercise you’ll be up for on the day of or the day after your flu shot. Again, keeping your body’s stress level low is a goal right after this shot. Generally, moving the arm you got your shot in is a good idea to prevent soreness, but high impact sports might not feel good while the spot is feeling tender. 

You may want to modify your routine for a couple days, especially if you’re feeling especially fatigued or if you have a fever or muscle aches. Walk instead of run. Go to a restorative yoga class instead of a high impact cardio boot camp. It’s also okay to take a recovery day or two if you feel like you need it.

2. Dehydration

Headache is one of the most common side effects of the flu shot—it’s also a key sign of dehydration. Making sure you’re getting enough fluids can help to alleviate that pain and help your body function better. That also means avoiding things that dehydrate you, including alcohol and caffeine if you’re feeling lousy.

Before you go out for a night on the town, check in with how you’re feeling. Although there is no contraindication with alcohol and the flu shot, Dr. Poinsett says you might want to avoid it because of the possibility of worsening flu shot side effects.

 “You might feel headaches and tiredness after drinking, which may add to the exhaustion and headache that you may have after a flu shot,” she says. “You may want to avoid alcohol until the headache and tiredness have passed after receiving a flu shot.” Drinking alcohol also affects the immune system and may reduce the effectiveness of the vaccine. If you do have a glass of wine or a beer with dinner, keep a close eye on your hydration levels and symptoms and try to avoid dehydration or headache.

3. Junk food

When you’re tired or under the weather, it can be tempting to reach for a bag of potato chips or box of cookies. Even though there are no food restrictions after a flu shot, if you’re feeling unwell, Dr. Williams says you should eat plenty of fruits, vegetables, and whole grains to give yourself the nutrients you need to recover. (This is good advice for all days, not just ones in which you received a vaccine.)

There is a misconception that you should avoid eggs after a flu shot. This is because people who have an egg allergy can have a life-threatening, severe allergic reaction to the flu shot. Many flu shots contain egg proteins , but if you’re able to eat eggs without an allergic reaction, you can also eat them after your flu shot.

4. Painkillers

If you have a headache, fever, muscle aches, or soreness at your injection site, Tylenol (acetaminophen) is the preferred option. Other painkillers might not be recommended. “Ibuprofen and naproxen may interfere with and dilute the power of the vaccine,” Dr. Poinsett says. Or, for localized pain at the injection site, use a cold compress. 

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Other practices to help avoid the flu

Even with a flu shot, you may still contract the flu, especially if it’s a particularly virulent strain of flu virus or if that year’s vaccine doesn’t protect against all types of flu that go around that year. Even when vaccinated, the vaccine effectiveness varies. So, it’s still important to follow risk reduction practices to help keep the spread of influenza down. The CDC has some guidelines on how to prevent the flu.

Some practices to help avoid the influenza virus are similar to those you learned during the pandemic to avoid COVID-19. They include:

• Wash your hands with soap and water for at least 20 seconds 
• Use hand sanitizer when soap and water are unavailable
• Avoid touching your eyes, nose, and mouth 
• Avoid crowded places and close contact
• Stay home when sick
• Consider masking in public during high infection rate periods
• Avoid contact with people who are sick
• Cover coughs and sneezes with a tissue and then dispose of the tissue
• Clean and disinfect high-touch surfaces 

In this day and age, if you get sick it’s also important to look at your symptoms and compare them to both a common cold and COVID-19. The CDC has created infographics to help you learn the differences between the flu and a cold and the flu and COVID-19. If you’re wondering if you have the flu and you’ve tested negative for coronavirus, your healthcare provider can offer you guidance or tests to determine the best course of action. If you do get the flu, follow your healthcare provider’s instructions on how long to stay home and any other care recommendations they may have. For certain groups, your provider may prescribe an antiviral medication, such as Tamiflu, to shorten the duration of your illness.