Quick answer: Most side effects of the pneumonia vaccine are mild and short-lived, such as soreness where the shot was given, fever, fatigue, headache, and muscle aches. Serious reactions are rare, but trouble breathing, hives, swelling of the face or throat, or a fast heartbeat need urgent medical help.

Common side effects

  • Redness, swelling, pain, or tenderness at the shot site.
  • Fever or chills.
  • Feeling tired.
  • Headache.
  • Muscle aches or joint pain.
  • In young children, fussiness or irritability and loss of appetite.

Rare but serious reactions

  • Severe allergic reaction, including hives, swelling, chest tightness, or trouble breathing.
  • Fainting, dizziness, or a rapid heartbeat.
  • Any symptoms that feel severe, unusual, or get worse instead of improving.

When to get help

If symptoms are mild, they usually go away within about 2 days. If you have trouble breathing, swelling of the face or throat, or signs of a severe allergic reaction, seek emergency care right away.

If you want, I can also give you a very short version or a side effects list for kids vs adults.