NEW YORK, July 13 — Johnson & Johnson and AstraZeneca are conducting early research into whether modifications to their Covid-19 vaccines could eliminate or reduce the risk of rare blood clots linked to the shots, the Wall Street Journal reported, citing people close to the process.

WSJ today reported that outside scientists and AstraZeneca’s partner, the University of Oxford, were also involved in the efforts.

AstraZeneca and J&J did not immediately respond to Reuters’ request for comment.

Both vaccines have been linked to the risk of blood clots, though regulators have said that benefits of the vaccines largely outweigh the risks. — Reuters