Johnson & Johnson personally reached out to Covid-19 vaccine competitors 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 Moderna Inc. refused.
Regarding concerns raised last week about rare cases of blood clots, J&J asked AstraZeneca PLC as well as Pfizer and Moderna to pool their efforts in investigating the reports, people familiar with the matter said. J&J also tried to build an informal alliance through emails and phone calls to communicate the benefits and risks of the shots and to allay any concerns raised in the public by the cases of blood clots, some people said.
Six women who received J & J’s vaccine developed blood clots and one died, according to federal health officials, of more than seven million doses administered in the US. The specific side effect has not been reported by people who received the Pfizer and Moderna shots, the officials said.
Pfizer and Moderna executives declined the offer, saying their vaccines appeared to be safe, the people said. The couple also objected because they didn’t see the need to duplicate the efforts of regulators and companies already looking for cases of blood clots and investigating the cause, the people said. One company’s concern: The security of the Pfizer and Moderna shots could be compromised by association, some people said.
Only AstraZeneca, plagued with similar blood clotting problems for weeks, agreed, the people said.