Prevenar 20 Side Effects: What Is Normal, How Long They Last and When to Get Help
October 15, 2026
5 minute read
Most people have some reaction to the Prevenar 20 pneumonia vaccine, usually a sore arm and perhaps a day or two of aches or tiredness. This guide uses the figures from the clinical trials to show how common each side effect is at your age, explains what is normal and how long it lasts, and makes clear when you should get help.
How common are the side effects at your age?
In the clinical trials, side effects were reported less often the older people were. For example, pain where the injection was given was reported by 79.2% of adults aged 18 to 49, but by 55.4% of those aged 60 and over. Choose your age group below to see the figures, then tap any symptom to check whether it is normal.
Interactive: side effects
How common are Prevenar 20 side effects at your age?
Choose your age group. Figures come from the clinical trials in the official product information.
Source: Prevenar 20 Summary of Product Characteristics. Usually mild or moderate, and settled within a few days.
Is this normal? Tap what you are feeling
General information, not medical advice. If you are worried, contact us on 0208 567 0982 or seek medical advice.
Less common side effects
Less common side effects reported in adults include redness or swelling where the injection was given, a raised temperature, feeling sick, diarrhoea or vomiting, a rash, and swollen glands. Serious allergic reactions are very rare. That is one reason we ask you to wait with us for a short time after your injection.
How long do side effects last?
Most side effects start within a day or two of the injection and settle within a few days. A sore arm is usually the first to appear and the first to go. If anything lasts longer than a few days, or gets worse rather than better, contact us.
How to ease side effects
- Keep your arm moving. Gentle movement helps a sore arm settle faster than keeping it still.
- Use a cool compress on the injection site if it is tender or swollen.
- Rest and drink plenty of fluids if you feel tired or achy.
- Take simple pain relief, such as paracetamol, if you need it, following the pack instructions.
- Plan a quiet evening after your appointment, especially if you are having other vaccines at the same time.
Side effects when given with flu or COVID-19 vaccines
Prevenar 20 can be given at the same time as other vaccines, in a different arm, and we are happy to give it alongside your flu, COVID-19 or shingles vaccine. The official product information includes studies of it given alongside flu and COVID-19 vaccines:
- With a COVID-19 mRNA vaccine, a raised temperature (13%) and chills (26.5%) were reported more often than with Prevenar 20 alone.
- With flu vaccine, side effects were similar to those with either vaccine on its own.
If you would rather avoid feeling under the weather from two vaccines at once, we can space them out. Read more about timing Prevenar 20 with other vaccines.
When to get help
| If you have | What to do |
|---|---|
| Swelling of the face, lips, tongue or throat, difficulty breathing, or feeling faint with a racing heart | Call 999 immediately |
| A rash or hives, especially if it is spreading | Contact us or seek medical advice the same day |
| Side effects lasting more than a few days, getting worse, or a high temperature that will not come down | Call us on 0208 567 0982 or seek medical advice |
| A sore arm, aches, tiredness or a headache | Usually normal. Rest and simple pain relief |
Reporting a side effect
You can report any suspected side effect to the MHRA through the Yellow Card scheme. Reports help keep track of vaccine safety in the UK. You are also welcome to tell us, so we can record it and advise you.
Who should check with us first?
Tell us before your appointment if you have had a severe allergic reaction to a vaccine before, have a bleeding disorder or take blood thinners, are pregnant or breastfeeding, or have a weakened immune system. Our Prevenar 20 guide explains who should not have the vaccine. If you had Pneumovax 23 in the past, see Prevenar 20 after Pneumovax 23.
Frequently asked questions
What are the side effects of Prevenar 20?
The most common are pain where the injection was given, muscle aches, tiredness, headache and joint pain. They are usually mild or moderate and settle within a few days.
How long do Prevenar 20 side effects last?
Usually a few days at most. Contact us if they last longer or get worse.
Can Prevenar 20 make you feel unwell?
Some people feel tired, achy or slightly feverish for a day or two. That is the immune system responding, and it passes.
Can the pneumonia vaccine give you pneumonia?
No. Prevenar 20 contains no live bacteria, so it cannot cause pneumococcal infection.
Are side effects worse if I have it with my COVID-19 vaccine?
Fever and chills are more common when the two are given together. We can space them out if you prefer.
Can I go to work after Prevenar 20?
Most people carry on as normal. If you have a physical job, you may notice a sore arm for a day or two.
To find out more about the vaccine itself, including who it is recommended for and how it compares with other pneumonia vaccines, read our complete Prevenar 20 guide. For pricing, see our pneumonia vaccine cost guide, and if you are in your 50s, our guide to the pneumonia vaccine for over 50s.
Sources: Prevenar 20 Summary of Product Characteristics; UKHSA Green Book, Chapter 25 (July 2026); MHRA Yellow Card scheme. This page is general information, not a substitute for individual medical advice. If you are worried about a reaction, seek medical advice.
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