A health worker holds a vial of the Janssen (Pharmaceutical Companies of Johnson & Johnson) vaccine against COVID-19 in Kathmandu, Nepal, 12 July 2021.  The United States of America through COVAX supplied on 12 July 2021, 1. 5 million doses of Johnson & Johnson vaccine against COVID-19 to help struggling Nepal in its vaccinaton drive for its citizens.   EPA / NARENDRA SHRESTHA

Johnson and Johnson Covid-19 vaccine linked to rare syndrome: what's the risk?