A local public health expert is offering words of reassurance when it comes to the Johnson & Johnson coronavirus vaccine. Distribution of the one-dose vaccine has been put on hold amid concerns that it could cause blood clots in a small number of recipients. In an interview with GBH All Things Considered host Arun Rath, Dr. Daniel Kuritzkes, chief of the infecious diseases division at Brigham and Women's Hospital, stressed that only a fraction of those who've gotten the vaccine have developed clots.

"This is about one in a million, literally six [people] out of nearly seven million people who have received the J & J vaccine," Kuritzkes said. "But it is something that needs to be looked into, and so it's appropriate that there's been a pause while we gather more information."

According to Kuritzkes, the complication has developed within the first two weeks after vaccination and has been seen primarily in young women. "All of the people who got the vaccine several weeks ago have really little or nothing to worry about," Kuritzkes said.

On the risks that the pause may pose to the larger vaccination effort versus the benefits, Kuritzkes stressed the safety of all of the vaccine formulas in circulation, including that made by Johnson & Johnson. "I think it's important to emphasize that these vaccines overall are extraordinarily safe," Kuritzkes said. "Even the J & J vaccine. That one in a million event is really less likely than being in a car accident or some other significant catastrophe."

Kuritzkes said that the Johnson & Johnson vaccine, which the state has used to target populations that may benefit from a single vaccination appointment, would still be useful in those efforts once distribution resumes. "There would still be lots of people in whom this vaccine could be deployed who might otherwise be hard to reach," he said.