symptoms of this rare syndrome usually came up between 4 to 20 days after the first dose of the AstraZeneca vaccine. It usually appears as a headache that doesn’t go away with pain medication (like paracetamol or ibuprofen), vomiting, confusion and/or seizures.People should seek medical attention immediately if they experience any of the following symptoms:ATAGI (Australian Technical Advisory Group on Immunisation) have clearly said that the AstraZeneca vaccine can still be used in adults under 50 years.