The US Centres for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) said that a CDC vaccine database had uncovered a possible safety issue in which people 65 and older were more likely to have an ischemic stroke 21 days after receiving the Pfizer/BioNTech bivalent shot, compared with days 22-44.
An ischemic stroke, also known as brain ischemia, is caused by blockages in arteries that carry blood to the brain.
A monitoring system flagged that US drug maker Pfizer and German partner BioNTech’s updated Covid-19 shot could be linked to a type of brain stroke in older adults, according to preliminary data analysed by US health authorities.