The appearance of reactions after taking the COVID-19 vaccine is completely normal and happens due to the natural response of the immune system, which produces antibodies to fight the substance that was injected. It is this response that allows for immunity to be created, since the antibodies produced are the same ones that, in the case of a real infection with COVID-19, will fight the virus.
Reactions to the vaccine usually appear within the first 24 hours and the most common are:
- Pain, swelling and/or redness at the injection site;
- Headache;
- Fever and chills;
- Feeling tired;
- Muscle and/or joint pain.
These reactions can last for 2 to 3 days. In the case of vaccines that require more than one dose, general reactions such as fever, headache and muscle pain are more frequent after the second dose, as pain and swelling in the arm can occur at all doses. See how many doses are needed for each vaccine.
Vaccination is the best way to protect against a serious infection with COVID-19 and, therefore, it should be carried out despite causing some adverse reactions. Non-vaccination does not cause any kind of reaction, but neither does it protect against the coronavirus, nor does it decrease the chances of a serious, life-threatening infection.
How to alleviate vaccine reactions
Although COVID-19 vaccine reactions can be a little uncomfortable and affect the daily lives of the vaccinated person, there are some ways to alleviate them:
1. Pain, swelling and redness at the injection site
To alleviate these symptoms, just apply a little ice (covered with a clean cloth) to the area for 10 to 15 minutes, several times a day. This will reduce the inflammation at the site, alleviating the discomfort.
It is also important to avoid straining with the vaccinated arm, such as lifting weights, especially in the first 2 days.
2. Headache and fever
To relieve headache and fever it is important to rest. However, some natural techniques can help, such as placing a cloth dampened with cold water on the forehead, avoiding wearing very warm clothes and drinking ginger or valerian tea, for example. Check out a list of the top teas to relieve headache and fever.
In addition, and with the guidance of a healthcare professional, paracetamol can also be taken every 8 hours. This is an antipyretic medicine that allows you to lower your body temperature, fighting fever.
If the fever lasts for more than 2 days or if it does not improve with the use of medication, it is important to go to the hospital to identify the possible cause and start the appropriate treatment.
3. Tiredness and muscle or joint pain
The best way to recover from fatigue and relieve muscle and/or joint pain is to rest as much as possible, avoiding efforts such as lifting weights, cleaning the house or working out, for example.
It is also important to ensure proper hydration and nutrition for the body, drinking plenty of fluids and eating a balanced diet. Liquids can be water, teas, coconut water or natural juices. See what to eat to fight fatigue.
Possible serious reactions
Serious reactions to the COVID-19 vaccine are very rare, but they mostly happen in people who have a history of a severe reaction after taking any other type of vaccine.
These reactions can appear soon after vaccination or up to 4 weeks:
- Severe allergic reaction, usually within the first 30 minutes after vaccination;
- Formation of clots, which can cause thrombosis;
- Carditis.
Although they are very rare, these reactions must be identified as quickly as possible, so that they can be treated correctly, avoiding the appearance of sequelae.
In case of symptoms such as feeling short of breath, swelling of the face, severe headache, chest pain or swelling in the legs, it is important to seek medical help.
What causes vaccine reactions?
Reactions that arise after vaccination are the result of the immune system’s normal response to the substance that has been injected. This substance varies according to the type of vaccine, but it is always a harmless material, capable of imitating the coronavirus, stimulating the immune response. When this happens, the body produces antibodies that will be “on hold” if the true coronavirus enters the body. See more about how vaccines work, their effectiveness and safety.
It is common for reactions to be more intense after the second dose of the vaccine because the body already has reserve antibodies that were produced after the first dose. These antibodies act faster and harder against the injected substance.
What does it mean if there are no vaccine reactions?
Having no reactions or having very mild side effects does not mean that you do not have immunity to the virus. This is because the intensity of reactions is related to how each immune system responds to the vaccine and not the strength of the immunity conferred.
The only way to know whether or not you have immunity to COVID-19 is to perform a blood test for IgG and IgM antibodies. Learn more about testing for COVID-19.
when to go to the hospital
It is important to go to the hospital whenever you suspect a serious reaction to the vaccine. In addition, medical help should be sought whenever:
- Fever does not subside or lasts longer than 3 days;
- The swelling and pain in the arm does not improve after 3 days;
- Other symptoms suggestive of COVID-19 appear, such as severe coughing, feeling short of breath or loss of smell.
The vaccine is not capable of causing COVID-19, however, some people may come into contact with the virus a few days before, or soon after, vaccination. In these cases, the vaccine’s immunity is not yet active and, therefore, they may end up developing COVID-19. The effectiveness of the vaccine is only guaranteed 14 days after the last dose. See other common questions about the COVID-19 vaccine.
