COVID Booster: Dealing with the side effects
Tuesday, January 18, 2022

If you have received your booster dose of the COVID-19 vaccine or are due to, you might experience some side effects. While these are generally mild, it is good to know what to expect and how to deal with them.

Side effects of the booster

Most side effects are mild and should not last longer than a week, such as:

  • Feeling tired
  • Tenderness, swelling, redness or itching in your arm where you had the vaccine injection
  • Headache
  • Swollen lymph glands under the arm where you had the injection
  • Feeling achy
  • Nausea or vomiting
  • Fever (temperature of 38 degrees Celsius or above)

Tips to cope with booster side effects

It’s common to develop a fever (temperature of 38 degrees Celsius or above) after any vaccination.

This usually happens within 2 days (48 hours) of getting the vaccine. It usually goes away within 2 days.

To reduce discomfort from fever:

  • Drink plenty of fluids
  • Dress lightly
  • Take paracetamol or ibuprofen following the instructions on the box or leaflet

If your fever starts more than 2 days after you are vaccinated, or lasts longer than 2 days, you should self-isolate (stay in your room).

Phone your GP to arrange a COVID-19 test.

To reduce pain and discomfort where the booster is given:

  • Apply a clean, cool, wet washcloth over the area
  • Use or exercise your arm

Side effects can affect your ability to do daily activities, but they should go away in a few days.

In most cases, discomfort from pain or fever is a normal sign that the body is building protection.

Contact a doctor or healthcare provider:

  • If the redness or tenderness where the shot was given gets worse after 24 hours
  • If the side effects are worrying or do not seem to be going away after a few days

Information sources: HSE, NHS & CDC