Johnson & Johnson turned privately to rivals for the Covid-19 vaccine to ask them to join forces to study the risks of blood clots and speak with one voice on safety, but Pfizer Inc. and Moderna Inc. they refused.
Regarding concerns about rare cases of blood clots, J&J asked AstraZeneca PLC, as well as Pfizer and Moderna, to join forces in reviewing the reports, insiders said. J&J, through emails and phone calls, is also seeking to build an informal alliance to communicate the benefits and risks of the shots and to address any concerns raised by the public about the blood clot cases, some people said.
Six women who received the J&J vaccine developed clots and one died from more than seven million doses given in the United States, according to federal health officials. The specific side effect was not reported by people who received the Pfizer and Moderna shots, officials said.
Pfizer and Moderna executives declined the offer, saying their vaccines looked safe, people said. The two also objected because they did not see the need to duplicate the efforts of regulators and companies that are already looking for blood clots and investigating the cause, people said. One company̵
Only AstraZeneca, which has been stifled by such blood clotting fears for weeks, has agreed, people said.