Johnson & Johnson privately contacted rivals for the Covid-19 vaccine to ask them to join an effort to study the risks of blood clots and speak with one voice about safety, but Pfizer Inc. and Modern Inc. they refused.
Regarding concerns raised last week about rare cases of blood clots, J&J called on AstraZeneca PLC, as well as Pfizer and Moderna to join forces to analyze the reports, people familiar with the matter said. J&J, through emails and phone calls, also sought to build an informal alliance to communicate the benefits and risks of shootings and to address any concerns raised by the public about blood clots, 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 adverse event was not reported by the people who received the Pfizer and Moderna shots, officials said.
Pfizer and Moderna executives declined the offer, saying their vaccines seemed safe, people said. The pair also objected because they saw no need to duplicate the efforts of regulators and companies already looking for blood clots and investigating the cause, people said. A concern of a company: The security of Pfizer and Moderna photos could be tarnished by the association, some people said.
Only AstraZeneca, which has been hit by similar blood clotting problems for weeks, agreed, people said.