LONDON – The EMA’s safety committee has concluded that unusual blood clots with low blood platelets are a rare side effect of Johnson & Johnson Inc.’s COVID-19 vaccine and that a warning should be added to the label. The decision is based on all available evidence, which currently consists of eight reports from the U.S. of serious cases of thrombosis, one of which was fatal. All cases were in people under 60 years of age, and within three weeks after vaccination, the majority in women. One case occurred during the clinical trials.