Rare Side Effects Of Flu Shots
In addition to the common side effects listed above, there are a few rare side effects of the flu vaccine. According to the SingleCare survey, respondents experienced these more uncommon side effects:
Prevalence of uncommon flu shot side effects | |
---|---|
No reaction | |
1% | 2% |
Guillain-Barre syndrome is a neurological health condition that causes severe weaknessbut again, it is a very rare side effect of the flu shot. Some studies find 1 to 2 out of a million people get this complication after the flu shot, Dr. Hirsch explains. Other studies find no association. Guillain-Barre is more common after the flu than after the flu shot.
In rare instances, serious side effects may occur that warrant medical attention from your healthcare provider. Most people are asked to stay for observation after a vaccine, in case of syncope or dizziness, which typically happens within 20 minutes, says pediatric pulmonologistKunjana Mavunda, MD,of Kidz Medical Services of South Florida. But that is usually a psychosomatic reaction because those are people who tend to be anxious about shots.
So Why Does Sirva Happen
Dr. Donohue explains that doctors and nurses are properly trained in landmarking, or determining where a vaccine should be given in the arm and using the proper needle length. When a needle is injected too deep the deltoid muscle can be penetrated and structures within the shoulder can be damaged such as the rotator cuff or joint capsule, he explains. In very rare cases the axillary or radial nerves in the upper arm could be injured.
According to the 2012 case report, SIRVA is due to an inflammatory effect from vaccine administration into the subdeltoid bursa, or a fluid-filled sac located under the deltoid muscle in the shoulder joint.
A 2018 study published in the Canadian Pharmacists Journal, specified that it occurs when an injection is administered too high in the arm, and the vaccine is delivered to the shoulder capsule instead of the deltoid muscle.
What Exactly Is Sirva
Ken Donohue, MD, a Yale Medicine orthopedic surgeon and shoulder specialist, explains to Health that SIRVA is an extremely rare condition in which pain and loss of function in the shoulder occurs following a vaccinationusually within 48 hours of administration of an injection in people who had no shoulder issues prior to injection. It can result in shoulder pain, weakness, stiffness or nerve inflammation . In very rare cases, it can result in nerve injury.
Just how uncommon is it? I have seen very few cases of this in my patients as an orthopedic shoulder specialist, Dr. Donohue maintains. And because it is so rare, there is little information available about it.
According to a 2012 case report published in the Journal of the American Board of Family Medicine, the concept that adverse reactions, specifically those involving the shoulder, are very rare. At the time of the report, researchers noted that only a single article on the concept existed. Seven years later, research is still incredibly limited.
While any sort of vaccination can lead to SIRVA, researchers found the majority were the result of the influenza vaccine. According to the report, nearly all who have reported such an injury, developed it within 24 hours.
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Why Is The Shot Given In Your Arm
Muscle tissue, like that found in your arm, has a high concentration of blood vessels. This allows the cells of your immune system to effectively access and process the contents of the vaccine.
Additionally, a
Allergic Reactions To The Flu Vaccine

It’s very rare for anyone to have a serious allergic reaction to the flu vaccine. If this does happen, it usually happens within minutes.
The person who vaccinates you will be trained to deal with allergic reactions and treat them immediately.
Anyone can report a suspected side effect of a vaccine through the Yellow Card Scheme.
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Why Does It Happen
The symptoms of SIRVA stem from the shot going into the wrong part of your upper arm or due to trauma from the needle. Research suggests that this brings on inflammation, and it could injure body parts inside your shoulder like:
- Ligaments. These tough bands of tissue connect two bones in a joint.
- Tendons. These thick cords connect muscles to bones.
- Bursae. These fluid-filled sacs cushion bones, tendons, and muscles.
What About People Who Get A Seasonal Flu Vaccine And Still Get Sick With Flu Symptoms
There are several reasons why someone might get flu symptoms, even after they have been vaccinated against flu.
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What Protection Does A Flu Vaccine Provide If I Do Get Sick With Flu
Some people who get vaccinated may still get sick. However, flu vaccination has been shown in several studies to reduce severity of illness in people who get vaccinated but still get sick:
- A 2017 study showed that flu vaccination reduced deaths, intensive care unit admissions, ICU length of stay, and overall duration of hospitalization among hospitalized flu patients.
- Another study in 2018 showed that a vaccinated adult who was hospitalized with flu was 59% less likely to be admitted to an intensive care unit than someone who had not been vaccinated. Among adults in the ICU with flu, vaccinated patients on average spent 4 fewer days in the hospital than those who were not vaccinated.
In addition, its important to remember that flu vaccine protects against three or four different viruses and multiple viruses usually circulate during any one season. For these reasons, CDC continues to recommend flu vaccination for everyone 6 months and older even if vaccine effectiveness against one or more viruses is reduced.
Tingling In Arm And Hand After Flu Shot
The tingling sensation you may feel in your arm or hand after getting a flu shot is caused by the vaccine itself.
When the needle enters your muscle, it can cause a brief, sharp pain. This pain is usually followed by a dull ache that can last for a day or two.
The tingling sensation is caused by the vaccines reaction to the nerve endings in your muscle. This is a normal side effect and usually goes away on its own within a few hours.
In rare cases, the tingling may be accompanied by numbness, weakness, or paralysis of the affected arm or hand. This is known as a brachial plexus injury and is often caused by the needle going too deep into the muscle.
A brachial plexus injury is usually temporary and will resolve on its own within a few weeks. However, in rare cases, it can lead to permanent nerve damage.
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When To See The Doctor For Pneumonia Vaccine Side Effects
Serious side effects after receiving the pneumonia vaccination are rare, but not impossible. Call your doctor if you experience the following:
- Allergic reaction
- Severe allergic reactions only occur in about one in a million shots. An allergic reaction to vaccinations typically happens within a few minutes to a few hours after receiving the shot. Seek emergency medical attention at the first sign of an allergic reaction to the pneumonia vaccine.
What Else Should I Know
Some things might prevent a person from getting the flu vaccine. Talk to your doctor to see if the vaccine is still recommended if your child:
- has ever had a severe allergic reaction to a flu vaccination
- has had Guillain-Barré syndrome
Egg Allergy and the Flu Vaccine
In the past, people with an egg allergy had to check with their doctor about whether the flu vaccine was OK for them because it’s grown inside eggs. But health experts now say that the amount of egg protein in the vaccine is so tiny that it’s 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 vaccine in a doctor’s office, not at a supermarket, drugstore, or other venue.
Getting a Flu Vaccine During the COVID-19 Pandemic
The flu season seemed milder during the COVID-19 pandemic, as fewer people got infected or were hospitalized with the flu. This was probably tied to public health measures that protected against coronavirus, as they also protect against the flu. These included wearing masks in public, social distancing, and less travel. Increased flu vaccination rates also might have helped. If these precautions happen less, the rate of flu infections will go back up, so it’s still important to get a flu vaccine each year. People can get a flu vaccine at the same time they get the COVID-19 vaccine.
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Before Getting The Vaccine
How Much It Hurts May Depend On How The Shot Was Administered

Slow injections may cause more pain, according to research published in the journal Vaccine. Researchers compared pain measurements in slow versus fast injections among infants and found that a faster shot reduced injection-induced pain when it came to certain vaccines, including the flu shot. A slower injection time means more time for the needle to be in contact with the skin, which could lead to the needle moving around more or even potentially cause muscle tissue damage, both of which make you feel sorer.
While you cant exactly predict the style of the person giving you the shot, try stroking or applying gentle pressure to the skin near the injection site during the shot, said Michael Grosso, chief medical officer at Huntington Hospital in Huntington, New York. Just give the nurse or pharmacist a heads up if you want to do this step before they get started. They may opt to do it for you so that you dont accidentally get pricked.
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How To Avoid A Sore Arm After A Flu Shot
Its flu season, which means many of us are heading to our doctor or local clinic for a flu shot . As we continue to battle COVID-19, flu shots are more important than ever before.
No one wants to be hit with both viruses. The good news is that with one flu shot each fall, you can significantly lower your chances by 40% to 60% of contracting the flu .
But are you one of the few who walks away from your shot feeling like youve been punched in the arm? Not everyone gets a sore arm, but it is common, and the reason actually may surprise you.
Some individuals may develop swelling, a mild, low-grade fever and some moderate pain localized to where they received the shot, said Devin Minior, MD, chief medical officer for Banner Urgent Care. This is a natural response, and it means that your body’s immune system is working to build up a defense against the flu virus.
Why Do Some People Not Feel Well After Getting A Flu Shot
Flu vaccine side effects are generally mild and go away on their own within a few days. Some side effects that may occur from a flu shot include soreness, redness, and/or swelling where the shot was given, headache , fever, nausea, muscle aches, and fatigue. The flu shot, like other injections, can occasionally cause fainting.
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Can You Prevent Arm Pain Before Your Flu Vaccine
There aren’t really any good hacks to lower your risk of arm pain ahead of time, Jamie Alan, PhD, associate professor of pharmacology at Michigan State University, tells Health. “You can pre-medicate with something like acetaminophen or ibuprofen, but there is some evidence that taking these medications may make vaccinations less effective,” she says.
The Centers for Disease Control and Prevention backs this up: In listing out considerations to take before getting your COVID-19 vaccine specifically, the CDC says it’s “not recommended” to take over-the-counter medication like ibuprofen, aspirin, or acetaminophen before you get the vaccine to prevent side effects. That’s because “it is not known how these medications might affect how well the vaccine works,” the CDC says.
Basically, without a ton of conclusive evidence on how, if, or why pain relievers may impact vaccine effectiveness, you’ll probably want to err on the side of caution and skip them before your shot .
Another tip: Alan says it’s a good idea to relax your arm “as much as possible” before your shot to keep your muscles from tensing and prevent the needle from having to work a little harder to get in there.
And, while this won’t necessarily change whether you’re sore or not after, it’s generally a good idea to get your vaccine in your non-dominant arm, Dr. Schaffner says. “If you do get a sore arm, it will interfere less with your function,” he says. “You can write more easily and do the usual things.”
While You Cannot Contract The Flu From The Flu Shot Vaccines Like Any Medication Come With The Risk Of Side Effects
Common side effects include: Soreness, redness, or swelling where the shot was given low grade fever muscle aches or toughness/itching at the injection site. These reactions typically present soon after the flu shot and last one to two days.
If you experience a life-threatening allergic reaction, such as breathing problems hoarseness or wheezing hives paleness weakness increased heart rate or dizziness, seek medical attention immediately.
In some cases, symptoms of reaction persist and can develop into long-term illnesses.
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Why Does My Arm Hurt After A Flu Shot
- Pneumonia
- Lung Health and Diseases
Getting a shot at the doctor’s office might not be the most enjoyable experiencewith the needle and the doctor and that pesky arm pain that can come after for somebut vaccination is necessary to help your body defend itself against dangerous diseases, including seasonal influenza . There’s a reason CDC recommends everyone 6 months of age and older get a flu shot each year: Anyone can get the flu and it can hit hard. The 2017-2018 flu season particularly demonstrated the impact: Around 80,000 Americans lost their lives due to influenza and 900,000 people were hospitalized.
The flu shot is safe, and you cannot get the flu from the flu shot. Most people have little or no reaction to the flu shot and the most common side effect is some discomfort in your arm hours after receiving the vaccination, including soreness, redness and/or swelling. A sore arm is much better than catching the actual influenza viruswhich can knock you out for days or weeks with high fever, cough and muscle achesbut why do some people experience this particular side effect of the flu shot?
What Are Common Flu Vaccine Side Effects To Expect
According to the CDC, you may experience short-lived, minor side effects of the flu shot or nasal spray vaccineas is the case with any vaccination or medication. You might think that side effects are a bad thing, but theyre actually signs that your immune system is responding and getting ready to protect you.
Heres how it works: The flu shot contains inactivated or incomplete strains of the influenza virus, while the nasal spray contains live attenuated strains. Neither form of the vaccine contains live flu viruses that can thrive in your body.
When you get any type of vaccine, the whole purpose is to expose your immune system to the virus, infectious disease expert Amesh A. Adalja, M.D., senior scholar at the Johns Hopkins Center for Health Security, tells SELF. Your immune system will start to rev up in response. These dead, partial, and weakened viruses are enough to provoke your immune system to develop antibodies to guard you against live and threatening flu viruses. It usually takes about two weeks for those to kick in and offer you protection, per the CDC.
Sometimes your immune system does this without causing noticeable symptoms, but other times, youll experience a few minor side effects as a result. Here are the most common ones you might experience:
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