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What Are Influenza Vaccine Side Effects?

It is not out of cynicism but curiosity to be concerned with the effects and the side effects of anything one consumes. The public’s lack of complete knowledge about and trust in the medicines and their ingredients makes it crucial to be interrogative about drugs. Out of this distrust, some rare conditions that involve only some individuals become a green light for many people to hold a grudge against vaccination. The influenza vaccine is not a different kettle of fish. There are a few rumors, or better to say, myths, about the influenza vaccine, such as getting the flu after receiving the influenza vaccine or the contraindication for those with chronic illnesses. In any case, the influenza vaccine has several side effects whose intensity, duration, and diversity depend on the vaccinated people’s background and current health condition. Although we can take these symptoms as a good sign to ensure that the vaccine works, things may go wrong for a portion of vaccinated people. 


Influenza Vaccine Side Effects

In a nutshell, the influenza vaccine is of little harm to most people. A couple of common side effects usually appear after a few hours since the vaccination and may subside within 24-48 hours. These side effects include feeling unwell, fatigue, muscle aches, and headache. Also, the spot where you get the shot may get sensitive briefly, carrying symptoms of swelling, soreness, and redness. If the injection site feels painful, a cold compress can be a great help to alleviate the pain. On top of these, some more severe side effects may cause trouble for you, like nausea, diarrhea, vision changes, fainting, difficulty breathing, ringing in the ears, dizziness, and vomiting, which are rare. All that being said, one of the most distressing symptoms is fever, which may occur within 48 hours of getting vaccinated. It is vital to ensure it fizzles out within 48 hours, or else things might be on the blink. You should consider visiting a doctor if you notice one or more rare side effects or prolonged fever.


During Pregnancy

Along with some of the myths mentioned earlier, there is another existing myth about the influenza vaccine that it negatively affects pregnant women. However, that is a myth and remains so. Contrary to such notions, pregnant women are more susceptible to infectious diseases since the immune system grows weak. This might give rise to a likelihood of getting the common cold and the flu. As the CDC suggests, pregnant women should have a mind to get a flu shot during the flu season. However, they should be cautious about the vaccine type and avoid nasal spray or live attenuated influenza vaccine; this type of vaccine (LAIV) contains weakened but live viruses and can bring about slightly more severe symptoms.


Vaccine Side Effects vs. Flu Symptoms

After getting a flu shot, it is natural to feel unwell under the side effects that appear within 48 hours. However, these side effects are similar to the flu symptoms, which may make you assume you are infected and leave you all worked up. Nevertheless, knowing that the body is not in a normal condition in the aftermath of vaccination is crucial. Some people find it strenuous to keep on track with daily work. You may develop a fever with a temperature of 37.8 °C or above, which might last for about two days. Besides, there might be body aches and overwhelming fatigue too. That said, it is generally recommended that everyone call a halt to their work and get some rest after the vaccination.


What to Do After Vaccination

Despite the mildness of these side effects for a large proportion of people, there are some considerations regarding the aftermath of vaccination that one should keep in mind. In general, it is best to steer away from stressful activities. This allows your body to focus on itself more. This is especially beneficial if you have muscle aches, a fever, or feelings of fatigue. Moreover, you’d better go picky about your food for a short while and give up on junk food. This, of course, is not a must-do, but taking fruits and vegetables instead of cookies and snacks can help your body recover faster. Additionally, coffee or alcoholic drinks may drive your body towards dehydration, which may end up in headaches. All that said, it is probable the muscle aches or the headaches stick around having done all that. There is no serious restriction on taking a painkiller after getting a flu jab. Yet, painkillers like Naproxen or Ibuprofen are better not to be taken since they interfere with the vaccine.  


Workout After Vaccination

Regular exercise is an advantageous natural way to elude the side effects or, at least, have subsided symptoms. There have been several types of research regarding the influences of exercising on the effects of vaccination. On the whole, physically active people show a better antibody response. That is due to better immune cell circulation in the bloodstream. Therefore, there is no need to be worried about working out if you usually exercise and have got a gym schedule. Besides, those who are not enthusiastic about workout will not face any severe problems exercising 90 minutes after getting vaccinated.


Who Should Avoid the Influenza Vaccine?

In general, anyone six months or older can get the influenza vaccine, though some options are preferred for specific ages. There is no limitation for pregnant women, people with egg allergies, or people with chronic health conditions. However, a group of people show intense allergic reactions to some ingredients—excluding the egg proteins— of the influenza vaccine and should avoid getting a flu jab. What is more, some individuals may specifically have an egg allergy, which can cause similar out-turns.  If you need to get a flu shot but find yourself in one of these groups or have had a disturbance with a dose of influenza vaccine previously, it’s best to ask your doctor for a guide. Lastly, those who have ever had Guillain-Barré Syndrome are recommended to avoid the influenza vaccine.


The Pros and Cons of Influenza Vaccine

We usually expect lifetime protection from vaccines that will keep us well against the pertinent viruses and bacteria 100%, such as vaccines for diphtheria or measles. This, however, is not true for any vaccine. As the best counterexample, the flu viruses are very contagious and can spread throughout the world rapidly. This characteristic eventually leads to constant mutation. That is why everyone needs to take the influenza vaccine yearly, as the vaccines also change by the virus. Still and all, not everyone can afford a flu shot every year, especially the majority of people in developing countries. There are several types of influenza vaccines, but the average cost of a flu shot dose is $60-70, which is a high price for many. That said, biosimilars are a suitable alternative carrying a couple of advantages over biological medicines, such as wider availability and a far more reasonable price tag. On account of these criteria, biosimilars are taking over the market, and many companies are investing more in this field. Opal Biopharma is an excellent case in point as one of the companies equipped with state-of-the-art technologies and focusing on biosimilar medications.



Besides the genetic mutations of the flu virus, the protection we acquire from the influenza vaccine is not permanent. Beginning about two weeks after receiving the shot, protection against the flu virus lasts about 6 to 8 months. The durability seems transient. Yet, it is essential to know that the golden time we need protection against the flu is from early fall to the end of spring.



The influenza vaccine is one of the safest, and except for a small group of people with allergies to different ingredients or anyone with a history of GBS (Guillain-Barré Syndrome), everyone six months and older is advised to get a flu jab once a year. The side effects mostly appear mild and transient, and there are a bunch of methods with which we can alleviate or avoid them. Some extreme symptoms, such as difficulty breathing, dizziness, and nausea, may occur once in a blue moon. Still, other ones are frequent, including fever, muscle pain, headaches, and localized soreness and swelling where you get the shot. As the last point, self-care is the best way to live through such side effects, which should not last more than 2-3 days. You can do that by taking lots of fluids, eating healthy food, and getting enough rest

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