The European Medicines Agency (EMA) is reviewing data related to the Johnson and Johnson Covid-19 vaccine.
The review comes as US regulators added a warning to the vaccine over links to a rare neurological reaction.
The US Food and Drug Administration (FDA) flagged reports of Guillain-Barre syndrome, which is an immune disorder that can cause muscle weakness, and occasionally paralysis.
US regulators reviewed the data and found that roughly 100 people developed the disorder and almost all required hospital treatment. One person also died as a result.
The EMA’s safety committee (PRAC) is analysing data provided by J&J and has asked the vaccine developer to provide further detailed data.
The J&J vaccine was recently made available for people aged 18-34-years-old in Ireland.