Flu Shot Side Effects : What’s Normal And What’s Cause For Concern
All vaccines have the potential to cause side effects, and that includes your yearly flu shot. But most are totally normal.
The coronavirus is still a very real concern this fall, but so is the influenza virus, aka the flu. The good news is we have very safe and effective tools for fighting and preventing both potentially deadly viruses, thanks to the COVID-19 vaccines and the flu vaccine.
According to the CDC, flu shots are safe and one of the best ways to keep from getting and spreading the flu to others. And people who get vaccinated and get sick anyway often experience less severe symptoms. If you’re thinking of getting vaccinated for both COVID-19 and the flu, the CDC says it is safe to get both vaccines together .
The simple fact is, flu vaccines can save lives. There are plenty of myths out there about the flu vaccine, such as the idea that it can give you the flu. While that’s not true, you can experience some side effects from the flu shot. The side effects are usually mild and nothing to worry about, but it’s important to know about them so you’re not worried when you get your vaccine.
Below, Dr. Carmen Teague, specialty medical director at Atrium Health‘s Mecklenburg Medical Group shares what you need to know about common flu shot side effects that are normal, and which side effects may be a sign of something more serious.
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Flu Vaccine For People With Long
The flu vaccine is offered free on the NHS to anyone with a serious long-term health condition, including:
- a learning disability
- problems with your spleen, for example, sickle cell disease, or if you have had your spleen removed
- a weakened immune system as the result of conditions such as HIV and AIDS, or taking medicines such as steroid tablets or chemotherapy
Talk to your doctor if you have a long-term condition that is not in one of these groups. They should offer you the flu vaccine if they think you’re at risk of serious problems if you get flu.
How Do I Know If I Have Side Effects Or If Im Sick
While vaccine side effects are common, the good news is they are usually mild and will resolve on their own in a few days. All vaccines can cause side effects. This is to be expected because vaccines trigger the immune system. But it is also possible to get a vaccine and not have any side effects at all.
Side effects can differ between vaccines, so it is important to review this information with your healthcare provider before you get the shot. For each vaccine approved in the U.S., the CDC publishes a Vaccine Information Statement . This document provides information about the benefits and risks of each vaccine, including common side effects. You can ask your healthcare provider for this information or find it here.
If you have symptoms after your vaccine that are more intense or last more than a few days, you may have another illness. You can discuss these symptoms with your healthcare provider to determine the cause and whether they are related to the vaccine.
Because side effects can be uncomfortable and frustrating, some people might try to prevent them by taking medications before a vaccination. But there is some evidence that taking medications like acetaminophen or ibuprofen before a shot may decrease your bodys immune response to the vaccine. For this reason, it is not recommended to take medication to prevent side effects before any vaccine, including the COVID-19 vaccine.
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Signs Of A More Serious Reaction
“A very small percentage of people can have a true allergic reaction to the vaccine, including chest tightness, difficulty breathing, wheezing, facial or throat swelling and redness of the eyes,” Teague says. If you experience these symptoms, you should seek medical attention immediately. Teague says severe allergic reactions usually happen within a few hours of getting the flu shot.
Signs of a severe allergic reaction, according to the CDC, can include:
- Difficulty breathing
- Swelling around the eyes or lips
- Hives
- Weakness
- A fast heartbeat or dizziness
Another possible reaction is an infection where the shot was administered. “Patients can also develop an infection at the injection site, which is manifested as worsening redness, swelling, warmth and tenderness,” Teague says. You should also seek immediate medical attention for this type of reaction.
The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.
What Do Allergic Signs Look Like

“Signs of an allergic reaction include the following when they happen within four hours after your first vaccine dose,” says the Mayo Clinic:
- Continuous shortness of breath or wheezing.
- Swelling of the lips, eyes or tongue.
- Redness, swelling or itchiness in areas of the body other than the limb in which the vaccine was given.”
“Call your health care provider if:
- You have common reactions that last longer than 3 days.
- Your reaction is so strong that you are worried about it.
Some of the COVID-19 vaccine reactions are the same as the symptoms for a COVID-19 infection. Typically, if you had these symptoms you would be tested for COVID-19. But when you know that your symptoms likely are due to the vaccine, you do not need to be tested. You do need to be tested for COVID-19: If you were in close contact in the last 2 weeks with someone who has COVID-19. If you have a cough, difficulty breathing, sore throat, vomiting, diarrhea, new loss of taste or smell, congestion, or runny nose. These are not reactions to the vaccine.”
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The Flu Shot And Covid
An important update regarding timing between receiving the flu and COVID-19 vaccines for all Victorians including those most vulnerable in our community.
The original recommended timing between receipt of the 2 vaccines was a preferred minimum interval of 2 weeks .
Based on the latest medical advice the preferred minimum interval between vaccinations for COVID-19 and the flu is now 7 days.
Period Problems And Unexpected Vaginal Bleeding
Some women have reported temporary changes in their periods after receiving the coronavirus vaccine. Some women have reported heavier bleeding than usual, delayed periods or unexpected vaginal bleeding. The MHRA and other experts are closely monitoring and evaluating these reports. Longer term follow-up is ongoing in the UK and elsewhere to better understand this reaction.
Current evidence suggests there is no link between period problems or unexpected vaginal bleeding and coronavirus vaccines. The number of reports is relatively low given the number of women who have taken the vaccine and how common period problems are generally. The menstrual changes reported usually do not last long. Whilst uncomfortable or distressing, period problems are extremely common and stressful life events can disrupt with your periods. Changes to the menstrual cycle have also been reported following infection with coronavirus and in women affected by long-COVID.
If you have changes to your periods that are unusual for you, persist over time, or you have any new vaginal bleeding after the menopause, following coronavirus vaccination, please speak to your GP.
As with all vaccines, you can report suspected side effects through the Yellow Card website.
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Reports Of Very Rare Blood Clots
The Medicines and Healthcare products Regulatory Agency is carrying out a detailed review of reports of a very rare blood clotting problem affecting a small number of people who have had the Oxford/AstraZeneca vaccine.
The problem can also happen in people who have not been vaccinated and it’s not yet clear why it affects some people.
The current reported rate of this condition in the UK is around 15 cases per million first doses given.
The coronavirus vaccine can help stop you from getting seriously ill or dying from coronavirus. For people aged 40 or over and those with underlying health conditions, the benefits of being vaccinated outweigh any risk of clotting problems.
For people under 40, it’s currently advised that it’s preferable to have either the Pfizer/BioNTech or Moderna coronavirus vaccine.
If you have already had a first dose of the Oxford/AstraZeneca vaccine without suffering any serious side effects you should complete the course .
This includes people aged 18 to 39 years who are health and social care workers, unpaid carers and those who live with someone with a severely weakened immune system.
Is It Normal To Get Chills After The Flu Shot Too
While its not a given that youd develop chills in addition to your fever, theres always a possibilitychills are also common post-flu shot. In general, chills occur right before a fever, Dr. Whyte says, so look out for those symptoms shortly after you get the shot.
And yep, chills are a part of the same immune response as when you get a fever: Upon injection, your body wants to increase its temperature to kill the virus. In order to do so, it sends a message to the brain that it needs to raise the temp, which then sends you into shivers or chills. These movements help create heat, carrying out your brains desire to raise your body temperature.
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Doctors Explain Why People Experience Flu
LANSING, Mich. – Doctors said people who receive the second dose of the COVID-19 vaccine are likely to experience flu-like symptoms including fever, headaches, chills, and body aches.
McLaren Emergency Department Medical Director Dr. Christine Perry said these symptoms are normal when receiving a vaccine.
Actually getting those symptoms are a good sign. Its a sign of a healthy immune system, said Perry. When we get that second dose of the vaccine, our bodies are even working harder and fighting harder to develop an immunity to COVID-19.
Claire Quainton received her second dose of the vaccine recently and said she is still battling a small headache.
The day of, I had some pain in the site of the injection, but thats pretty typical with any shot. The day after I had body aches, joint pain, nausea headache, low-grade fever, It was just high enough they wouldnt let me work. But I probably wouldnt have worked anyway, said Quainton.
Quainton said she has no doubt the vaccine is working.
She said, Its a natural immune response. So, it didnt deter me, it didnt scare me, its just part of getting a vaccine.
Some people are against receiving the vaccine because of how quickly it was made, but Dr. Perry said its safe and she has faith that it works.
Dr. Perry said the symptoms are manageable and last between 12 and 48 hours.
She said to avoid taking Motrin or Tylenol for the first eight hours after the shot.
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Making Sure Vaccines Are Safe
Vaccines must be tested to make sure theyre safe and effective before being approved for use in Canada. Once a vaccine has been approved for use in Canada, its monitored for:
- safety
- effectiveness in people
Health Canada and the Public Health Agency of Canada share the responsibility for ongoing safety monitoring, which also involves:
- provincial, territorial and local public health authorities
- health care professionals
Experts have developed many different types of vaccines to protect us from germs .
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Headache And Other Aches And Pains
After your shot, you might have headaches or some achiness and pain in the muscles throughout your body. This also usually happens on the first day and goes away within two days. Taking pain relievers can help ease your discomfort.
Its controversial whether its safe to take acetaminophen or ibuprofen to treat these vaccine side effects.
Some research suggests that these medications might change or decrease how your body responds to the vaccine. One study involving children found that taking acetaminophen or ibuprofen didnt reduce the bodys response to the flu vaccine.
Other research is mixed. Its still unclear whether these medications should be avoided.
What’s New With The 2021

There are many types of flu virusesand each consistently changes. This means that the U.S. flu vaccines are reviewed every year to prevent against the currently circulating flu viruses. This year’s vaccines are all “quadrivalent,” according to the CDC, meaning they’re designed to protect against four different viruses that cause the flu.
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What Is The Pneumonia Vaccine
The pneumonia vaccine is an injection that prevents you from contracting pneumococcal disease. There are two pneumococcal vaccines licensed by the Food and Drug Administration for use in the United States:
The Center for Disease Control recommends the PCV13 vaccine for:
- All children younger than 2 years old
- People 2 years or older with certain medical conditions
The CDC recommends PPSV23 for:
- All adults 65 years or older
- People 2 through 64 years old with certain medical conditions
- Smokers 19 through 64 years old
Waiting Time After Your Coronavirus Vaccination
Due to the Omicron variant, the adult booster programme is being rolled out faster.
Given the very low rate of serious allergic reactions , the 15-minute wait has been reduced to 5 minutes, as long as you feel okay. This change has been advised by the 4 UK Chief Medical Officers. It’s also supported by the Medicines Healthcare products Regulatory Agency and the Joint Committee on Vaccination and Immunisation .
Make sure you tell the vaccination staff if you:
- have a history of allergies, particularly to other vaccines
- if you had an immediate reaction after your previous doses
- if you have previously fainted following vaccination
In these circumstances, you may be advised to stay for 15 minutes. A family history of allergies is not a risk factor.
You must not drive for 15 minutes after the vaccine because of the risk of fainting.
If you experience symptoms of an allergic reaction, call out for help and/or phone 999 immediately . Symptoms usually happen within 15 minutes of vaccination.
You should look out for the following allergic symptoms:
- persistent cough
- swollen tongue causing difficulty swallowing
- difficult or noisy breathing
- wheezing
- feeling lightheaded or prolonged faint
- clammy skin
More information is available in the Waiting after the coronavirus vaccination leaflet.
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Are There Other More Serious Side Effects
There have been reports of an extremely rare condition involving blood clots and unusual bleeding after the AstraZeneca and Janssen vaccines. Because of the high risk of complications and death from COVID-19, the Medicines and Healthcare products Regulatory Agency , the World Health Organization and the European Medicines Agency have concluded that the balance is very much in favour of vaccination.
If you experience any of the following from around 4 days to 4 weeks after vaccination you should seek medical advice urgently:
- a new, severe headache which is not helped by usual painkillers or is getting worse
- an unusual headache which seems worse when lying down or bending over or may be accompanied by
- blurred vision, nausea and vomiting
- difficulty with your speech,
Quadrivalent Vaccines For Seasonal Flu
A quadrivalent flu vaccine administered by nasal mist was approved by the FDA in March 2012. Fluarix Quadrivalent was approved by the FDA in December 2012.
In 2014, the Canadian National Advisory Committee on Immunization published a review of quadrivalent influenza vaccines.
Starting with the 2018-2019 influenza season most of the regular-dose egg-based flu shots and all the recombinant and cell-grown flu vaccines in the United States are quadrivalent. In the 2019â2020 influenza season all regular-dose flu shots and all recombinant influenza vaccine in the United States are quadrivalent.
In November 2019, the FDA approved Fluzone High-Dose Quadrivalent for use in the United States starting with the 2020-2021 influenza season.
In February 2020, the FDA approved Fluad Quadrivalent for use in the United States. In July 2020, the FDA approved both Fluad and Fluad Quadrivalent for use in the United States for the 2020â2021 influenza season.
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Tts Myocarditis And Pericarditis
There is a very rare and serious risk of a condition called thrombosis with thrombocytopenia with AstraZeneca COVID-19 vaccine and myocarditis or pericarditis from Pfizer or Moderna COVID-19 vaccines. These conditions require immediate medical attention.
See your doctor or health care professional as soon as possible or go directly to a hospital if:
- you have a reaction that you consider severe or unexpected
- you are concerned about your condition after vaccination.
Seek medical attention immediately if you experience any of the following symptoms:
- neurological symptoms, including severe and persistent headaches or blurred vision
- shortness of breath
- swelling in your leg
- tiny blood spots under the skin beyond the site of injection.
For specific advice about side effects from different doses of vaccines, call the National Coronavirus Helpline on or ask your doctor or health care professional.