A person walks past a sign that says, “The Vaccine Is Our Best Chance Against COVID-19” on the Upper West Side amid the March 30, 2021 coronavirus pandemic in New York City.
Noam Galai | Getty Images
Johnson & Johnson privately asked Covid-19 vaccine competitors Pfizer and Moderna to participate in an investigation into the potential risk of blood clots, but the companies declined, The Wall Street Journal reported Friday, citing people familiar with the matter.
Executives at Pfizer and Moderna said their vaccines appeared to be safe and they did not see the need to duplicate the efforts of regulators and companies already looking at the rare blood clot problem, the Journal report said.
Only AstraZeneca, whose vaccine has also raised regulatory concerns about blood clots, agreed to join the effort, the Journal said.
CNBC has contacted the four companies for comment.
On Tuesday, the Food and Drug Administration and the Centers for Disease Control and Prevention advised states to temporarily suspend use of J & J’s vaccine “ out of great caution ” after six women developed a rare but potentially life-threatening blood clotting disorder that left one death and one in critical condition behind.
The women developed the condition known as cerebral sinus vein thrombosis, or CVST, within about two weeks of receiving the injection, U.S. health officials told reporters. CVST is a rare type of stroke that occurs when a blood clot forms in the venous sinuses of the brain. It can eventually leak blood into the brain tissue and cause bleeding.
A CDC panel decided on Wednesday to delay a decision on the use of J & J’s vaccine while officials are investigating the cases.
Read the full Wall Street Journal report here.