Like any vaccine, COVID-19 vaccines can cause mild, short term side effects, such as a low-grade fever or pain or redness at the injection site. Most reactions to vaccines are mild and go away within a few days on their own. More serious or long-lasting side effects to vaccines are possible but extremely rare. Vaccines are continually monitored for as long as they are in use, to detect rare adverse events and implement approaches to limit their occurrence.
Reported side effects to COVID-19 vaccines have mostly been mild to moderate and short-lasting. They include: fever, fatigue, headache, muscle pain, chills, diarrhoea, and pain at the injection site. The chances of any of these side effects following vaccination differ according to the specific COVID-19 vaccine.
In most cases, these can be managed with rest, plenty of non-alcoholic liquids, and paracetamol/acetaminophen for the typical side effects. Contact your care provider if the tenderness (pain) where you got the injection increases after 24 hours, or the side effects do not go away within a couple days. If you have difficulty breathing, chest pain, confusion, loss of speech or mobility, call a healthcare provider immediately.