Can COVID-19 Vaccine Really Cause Serious Allergic Reactions?

June 25, 2021 | Written By: Nabil Nur Aiman Jasman

Can COVID-19 Vaccine Really Cause Serious Allergic Reactions?

The Purpose Of COVID-19 Vaccine

The National COVID-19 Immunization Program was launched by the Prime Minister of Malaysia, Tan Sri Muhyiddin Yassin on 24 February 2021 as a measure to stop and prevent the spread of COVID-19 in our country. The program is divided into three phases and is expected to complete in February 2022 where about 80% of Malaysians are expected to complete the vaccination.

This COVID-19 vaccine is given with the aim of activating the immune system to build defense against the COVID-19 virus before you get infected with the actual virus. Vaccines train the body to produce proteins called antibodies that work to protect the body from infection. 

As with other medications and treatments, there are side effects that can occur when a person receiving the vaccine such as allergic reactions. However, the risk for a person to get side effects of an allergic reaction after the vaccine is low, which is around 1 in 100,000 injections.

Vaccine Side Effects

This vaccine will be injected into the deltoid muscle in your shoulder, either on the left or right side. After the injection, you will be monitored for 30 to 40 minutes to see if you experience any side effects or not. The side effects of the vaccine are usually not serious and will heal in a short time. Here are some side effects of COVID-19 vaccine in general:

Local (At The Site of Injection):

  • Pain

  • Redness

  • Swelling

  • Itching

  • Infections

Systemic (Whole Body):

  • Fever

  • Weakness and lethargy

  • Diarrhea

  • Headache

  • Dizziness

One of the rare side effects experienced by a person who receives the vaccine is the allergic reaction or anaphylaxis which is a more severe and potentially life-threatening allergy if not treated immediately. Among the symptoms of allergic reactions are as follows:

  • Skin reactions such as rashes and itching

  • Difficulty breathing due to narrowing of the airway

  • Weak and rapid pulse

  • Pain and dizziness

  • Nausea, vomiting and diarrhea

  • Fainting

Vaccine Exemption

If you meet one of the criteria below, you are excluded from receiving the vaccine:

  • History of hospitalization due to COVID-19 infection

  • Had a history of allergies to previous vaccines

  • Have an allergy towards the ingredients used in the vaccine received

  • Have an allergic reaction after receiving the first dose of COVID-19 vaccine

  • Being pregnant

  • Currently breastfeeding

How to Deal with Allergic Reactions

Although these allergic reactions are dangerous if they occur, they are easy to deal with if the symptoms are detected early. On average, most individuals who experience an allergic reaction post-vaccination will show symptoms around 15 minutes after getting the injection when the immune system has begun to actively respond. Depending on the symptoms experienced, each symptom will be addressed and treated in a different way.


What Should You Do If You Have An Allergic Reaction?

Serious Allergic Reactions:

If you experience serious side effects after receiving the first dose injection, you should not get a second dose. According to the Centers for Disease Control (CDC) a person with a serious allergic reaction (anaphylaxis) should be treated immediately in a hospital using epinephrine and several other supportive treatments to relieve the symptoms experienced.

Less Serious Allergic Reactions:

Even if you have a less serious allergic reaction and do not require immediate attention by a doctor and emergency treatment in some cases, you also do not need to get a second dose of COVID-19 vaccine. Most allergic reactions occur about four hours after the injection is given. Among the less serious allergic reactions but should be noted is when your breath sounds (due to narrowing of the airways), an itchy rash and swelling appear. You will be placed in a surveillance room or sent to the hospital immediately if you experience the symptoms mentioned.

Having a rash 

If there is a rash around the area of ​​the vaccine injection, you can take a second dose but in a different area at the scheduled time. The effects of the rash at the injection site can last for days or weeks. 

If you experience discomfort in the injection site, you can do some of the things below:

  • Apply a clean, damp towel to the injection site

  • Do light arm exercises to reduce pain

  • Take painkillers if uncomfortable

  • Take antihistamine if there is itching at the injection site


When To See A Doctor?

You are required to go to a nearby hospital or clinic if you:

  • Still experiencing discomfort despite medication being taken

  • The injection site becomes increasingly sore and there are inflammatory reactions such as swelling and pus

  • Having breathing problems such as difficulty breathing and chest pain

If you are experiencing any problems or allergic reactions after getting the first or second dose of COVID-19 vaccine, you should contact the doctor or clinic where you received the injection so that a record of the side effects of the vaccine can be taken and appropriate treatment can be given to you. The side effects you reported are important for the safety monitoring of the vaccine and the data will be updated from time to time for future improvements to the COVID-19 vaccine. You do not have to worry because the side effects of the vaccine are mostly mild and the doctor is always ready to treat if you show side effects from the vaccine. 



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