Health Canada said it has recommended that people with a history of capillary leak syndrome (CLS) not be inoculated with AstraZeneca's Covid-19 vaccine, Reuters reports.

“Health Canada is updating the product monograph — or label — for the AstraZeneca and Covishield Covid-19 vaccines to add CLS as a potential side effect, with a warning for patients with a history of CLS to not get the AstraZeneca or Covishield Covid-19 vaccine," it said in a statement.

CLS is a very rare, serious condition that causes fluid leakage from small blood vessels (capillaries), resulting in limb swelling, low blood pressure, thickening of the blood and low levels of an important blood protein.

Health Canada and the Public Health Agency of Canada have been monitoring this condition since it was raised as a potential safety concern by the European Medicines Agency in April, the statement added.