Serious side effects are very rare, but if you experience any of the following from around 4 days to 4 weeks after vaccination you should seek medical advice urgently.
- A new, severe headache which is not helped by usual painkillers or is getting worse
- A headache which seems to get worse when lying down or bending over
- An unusual headache that may be accompanied by:
- Blurred vision, nausea and vomiting
- Difficulty with your speech
- Weakness, drowsiness or seizures
- New, unexplained pinprick bruising or bleeding
- Shortness of breath, chest pain, leg swelling or persistent abdominal pain