U.S. health officials were close to simply warning of the risk of blood clotting from Johnson & Johnson’s Covid-19 vaccine, but decided to recommend discontinuing use, out of concern that doctors would treat inappropriate condition, said people familiar with the problem.
In the last four weeks, US health officials have become alarmed about similar blood clotting conditions in Europe, involving a Covid-19 vaccine from AstraZeneca PLC, people said. Officials dug into a vaccine safety database in the United States and identified cases of great concern, but discussed what action to take.
Until last Monday night, officials decided that urgent action was needed, people said. Four out of six U.S. women who developed blood clots a few days after vaccination had initially received heparin, according to the U.S. Centers for Disease Control and Prevention. Its use could have aggravated the condition of patients, people said.
That evening, senior health officials in the country agreed during a one-hour Zoom meeting to take the strongest step: publicly recommend discontinuing the vaccine while examining cases of adverse events, people said.
Since the announcement, the Food and Drug Administration has studied other reports of additional blood clotting among people who received the J&J vaccine, but has not confirmed whether any of them reflect the same phenomenon, people said. However, officials are increasingly convinced, the people added, that the six cases reported so far are related to the shooting.