Posted on Leave a comment

All You Need to Know About Vaccine Side Effect


In the last decade, over 1 billion children have been vaccinated. Back in 2019, around 85% of newborns got 3 doses of the DTP3 (diphtheria-tetanus-pertussis) vaccine, protecting them from a serious disease, disability, and even death. Right now, immunization is preventing 4 to 5 million deaths annually.

The truth is, vaccines have spiked debates for a very long time. They are often the reason you are stuck in an awkward conversation with someone who doesn’t share the same view as you when it comes to vaccinations.

Yes, there will always be some level of fear and uncertainty. But, to understand the sheer impact of vaccination, it is crucial to take a look at all aspects that are surrounding it—even the bad ones. Just like any medication or a chemically manufactured product out there, vaccines can cause adverse effects.

Although, for the most part, they are minor, people are worried they could affect the quality of life. That’s why we decided to compile this comprehensive guide on vaccines and side effects. They will give you that valuable insight that you’ve been looking for.

What Are the Possible Side Effects?

COVID Vaccine

After receiving a vaccine, patients normally experience temporary side effects. They could last anywhere from a couple of hours to a few days after a dose. This is completely normal since it’s the body’s natural response system that’s reacting to the chemicals in the product.

The system is doing its best to create immunity to battle the disease. This is what experts refer to as a reaction or an inflammatory response. It is not uncommon for these reactions to get in the way of your daily life. Sometimes, you would need to take over-the-counter meds to cope with the aches or fever.

These typical adverse effects may include:

  • Reactions on the injected area. They are typically associated with swelling, redness, and pain.
  • Flu is accompanied by mild fever, muscle pain, chills, exhaustion, joint pain, or a headache.
  • Allergic reactions. When a patient is allergic to any of the products inside the vaccine, the body can react abnormally. It can result in swelling, rash, elevated heart rate, decreased blood pressure, vomiting, etc.

Do have in mind that side effects are also classified by the severity of impact. There are mild to moderate and moderate to severe problems. Mild side effects are the ones that cause mild rash, tenderness, swelling, or fever. Whereas the more complex ones can cause a bad rash, severe infection, and a weakened immune system.

Why Vaccines Have Side Effects?

Every day, our body is fighting external agents that are trying to invade our system. The cells, however, develop a memory of these invading pathogens. Therefore, the immune system becomes capable of recognizing the external agent.

These memory cells have one job – spot the virus that invaded the system and get the immune system to attack it. Vaccines are basically tools for these memory cells. So, when they enter the system, the body can fight it. There is always a chance that the patient’s body won’t react favorably to a vaccine. That’s because everyone is different, and their body reacts differently to the vaccine.

Then, there are stress-related reactions. When someone is very anxious about getting a vaccine, they can turn pale or start to sweat. They can feel lightheaded, their breathing pattern will start to speed up, and they could lose their sensations in the feet, hands, or face. These reactions, however, are not caused by the vaccine. They are triggered by the stress from getting one. When the patient calms down, these reactions disappear.

What Should People Do When Facing These Side Effects?

If you develop any of these reactions or effects, it is best to consult with a healthcare provider. To prevent the side effects from turning into an actual problem, it is best to sit in the hospital for at least 15 to 30 min post-vaccination to see how the system will react to it. For example, you can sit in your vehicle for a little while before you drive off. This can be a worthwhile strategy.

Those who develop injection site pain or fever typically take over-the-counter treatments. Like paracetamol, aspirin, or ibuprofen. Others like to rely on home remedies for relief. Such as a cold compress to relieve the stiffness and pain. If you are not feeling too well, it is crucial to drink plenty of fluids. This can help you avoid dehydration and ease the discomfort. 

Different Vaccines May Cause Different Side Effects

Not every vaccine has the exact same side effects. Each immunization provider ensures a unique impact on the human body. But, to understand the impact, it is important to take a look at each individualized side effect of a vaccine. The table below will give you a general outline.


Effect of illness​

Vaccine side effect​

Hepatitis A

Around 7 in 10 adults experience nausea, vomiting, fever, jaundice, tiredness, liver pain, etc.

Roughly 1 in 5 patients develop local swelling on the injected area. Serious reactions are very rare. 

Hepatitis B

An estimated 1 in 4 chronic carriers experiences liver cancer.

Anaphylaxis happens in 1 in 1 million people. While 2 in 100 develop a fever. Around 1 in 20 have local swelling. 


Around 1 in 15 children affected with measles experience pneumonia. 1 in 1000 develop brain inflammation. Some could experience permanent brain damage. 

Roughly 1 in 10 develop redness, pain, and swelling on the injected area. 1 in 20 have a non-infectious rash. 

Final Thoughts

As you can see, the sheer impact and benefit of any vaccine outweigh the possible side effects. Although there will always be a risk when taking chemical products, vaccines are a worthwhile choice. Not only to protect yourself but those around you as well. This is the kind of protective strategy everyone is looking for.