Side effects from immunization are common. These side effects are typically mild and temporary.
Not all children will experience side effects from immunization. Each child responds differently to vaccination, and the majority may experience no or minor side effects.
Most common side effects of immunization
The side effects of immunization can vary depending on the vaccine. The most commonly reported side effects are:
Fever
Fever after immunization is a normal body response. In many cases, it can help speed up immune system activity.
Fever typically develops within 12 hours of vaccination and lasts for 1-2 days. The fever is usually mild, with a temperature ranging from 37.8 to 39 degrees Celsius. Doctors usually advise against giving fever-reducing medication unless the child is uncomfortable.
Local reaction on the injection site
Some children feel pain, swelling, and redness at the injection site after receiving vaccinations. This is completely normal. It means that the vaccine is causing the immune system to produce a protective response against the intended disease.
Fussing and crying
Fussiness, crying, and restlessness during sleep are common reactions to vaccination. These are typically brought on by pain at the injection site or the body's natural reaction to the ingredients in the vaccine.
After vaccination, some children may sleep longer than usual or have a decreased appetite. There is no need to be concerned because this usually resolves itself within 1-2 days.
Formation of small lumps
Sometimes, after vaccination, a small, hard lump may develop at the injection site. This lump may last for a few weeks or even months. It is generally a harmless reaction to the vaccine's ingredients.
Unusual and rare side effects
In addition to common side effects, immunization can also cause uncommon and rare side effects, including:
Severe allergic reactions
Anaphylaxis is a severe allergic reaction that can occur following vaccination. Anaphylactic reactions to vaccinations are extremely rare and uncommon.
Anaphylactic reactions may occur within the first 15 minutes after receiving the vaccine. Shortness of breath, facial or throat swelling, rapid or irregular heartbeat, dizziness, fainting, and chest pain are some of the symptoms.
Brain or spinal cord inflammation
Inflammation of the brain (encephalitis) or the spinal cord (myelitis) is one of the few side effects of vaccination. Although extremely rare, side effects can appear within a few weeks of vaccination. Severe headaches, seizures, muscle weakness, difficulty speaking and moving, and sensory disturbances are all possible symptoms.
Guillain-Barré syndrome (GBS)
Guillain-Barré syndrome is a rare side effect of vaccination. GBS is a rare autoimmune disorder in which the immune system attacks peripheral nerves, resulting in nerve inflammation and muscle weakness that can be severe.
Symptoms of GBS can appear within a few weeks of vaccination, including rapid muscle weakness, difficulty moving or walking, and loss of muscle control.
Thrombosis syndrome with thrombocytopenia (TTS)
Thrombosis syndrome with thrombocytopenia (TTS) is also called vaccine-induced immune prothrombotic thrombocytopenia (VIPIT/VIIT). This is a rare syndrome reported in some people who received AstraZeneca and Johnson & Johnson's adenovirus-based COVID-19 vaccine.
This serious condition is caused by abnormal blood clotting and a decrease in platelet count. TTS symptoms include leg swelling or pain, chest pain, abdominal pain or swelling, severe headaches, double visions, and difficulty speaking.
While immunizations can cause side effects in some people, it is critical to remember that the benefits far outweigh the risks. Immunization has saved millions of lives and reduced the number of infectious diseases worldwide.
If you have concerns about immunization side effects, you should consult with your doctor to get accurate and reliable information.
If you need medical advice or consultation, you can either visit a doctor or make use of the consultation features that are available in the Ai Care application by downloading the Ai Care application from the App Store or Play Store.
Looking for more information about other diseases? Click here!
- dr. Monica Salim
Better Health Channel. Immunisation – side effects. Available from: https://www.betterhealth.vic.gov.au/health/healthyliving/immunisation-side-effects
UNICEF (2022). Top five reasons why immunization is important. Available from: https://www.unicef.org/india/stories/top-five-reasons-why-immunization-important
Seattle Children's (2023). Immunization Reactions. Available from: https://www.seattlechildrens.org/conditions/a-z/immunization-reactions/
Nicole Galan, RN (2023). When to Call Your Healthcare Provider About an Injection Side Effect. Available from: https://www.verywellhealth.com/injection-side-effects-call-doctor-2616542
NHS UK (2024). About COVID-19 vaccination, safety and side effects. Available from: https://www.nhs.uk/conditions/covid-19/covid-19-vaccination/about-covid-19-vaccination/
Olajide Bamidele Ogunjimi, et all (2023). Guillain-Barré Syndrome Induced by Vaccination Against COVID-19: A Systematic Review and Meta-Analysis. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10183219/
NSW Government (2021). Anaphylaxis after vaccination. Available from: https://www.health.nsw.gov.au/Infectious/covid-19/vaccine/Pages/management-of-anaphylaxis.aspx
Mariam Abdelhady, et all (2023). Encephalitis following COVID-19 Vaccination: A Systematic Review. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10054808/
Seyed Farzad Maroufi, MD, MPH, MPHE (2022). Longitudinally extensive transverse myelitis after Covid-19 vaccination: case report and review of literature. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9009891/
Daryl Cheng et all (2024). Thrombosis with thrombocytopenia syndrome (TTS). Available from: https://mvec.mcri.edu.au/references/thrombosis-with-thrombocytopenia-syndrome/