WELL: Johnson & Johnson Vaccine: US Calls for Pause After Blood Clotting Cases. “Federal health agencies on Tuesday called for an immediate pause in use of Johnson & Johnson’s single-dose coronavirus vaccine after six recipients in the United States developed a rare disorder involving blood clots within about two weeks of vaccination. All six recipients were women between the ages of 18 and 48. One woman died and a second woman in Nebraska has been hospitalized in critical condition.”

Six people isn’t very many, but given that they’ve been pushing the vaccines hard they must have been fairly concerned to pause this. It’s also going to make it harder to pooh-pooh people who have safety concerns about using these new vaccines in general. So far two out of four — Astra-Zeneca and J&J — have now faced some official action based on concern over clots.

Plus: “Federal officials are concerned that doctors may not be trained to look for the rare disorder if recipients of the vaccine develop symptoms of it. The federal health agencies said Tuesday morning that ‘treatment of this specific type of blood clot is different from the treatment that might typically be administered’ for blood clots.” Treatment with heparin can make it worse, so it’s important to distinguish from other kinds of blood clots where that’s the standard treatment.

UPDATE: David Bernstein posted on this from a different perspective, but I also agree with his take.