A Canadian advisory committee says Canadians who got the AstraZeneca shot for their first vaccine dose should not get the second one.

It says they should get the Pfizer or Moderna vaccine for their second shot instead.

The vice-chair of the board says new evidence suggests responses are better when the AstraZeneca vaccine is followed by an mRNA vaccine and said the new guidance also takes into account the marginal risk of blood clots associated with AstraZeneca.

However, she said anyone who got two shots of AstraZeneca can feel confident they are protected.

This story originally reported by Simon Kaufman and Jay Strubberg on Newsy.com

The referee who collapsed during the Elite Eight game between Gonzaga and Southern California in the 2021 men's NCAA tournament reveals it was caused by a blood clot in his lungs.

Bert Smith revealed the diagnosis in an interview with Gregg Doyel of the Indianapolis Star, which was released Friday.

Smith told Doyel he doesn't recall the collapse that occurred on March 30 nor remember what happened immediately afterward.

Still, he did remember why he looked disgruntled while on the stretcher: the doctor tricked him into sitting on the stretcher and strapping him in.

In an interview with Sports Illustrated, Smith said the collapse probably saved his life.

After the collapse, he was checked out by medical personnel but was cleared by them to return to the hotel.

While at the hotel, his colleagues, NCAA doctors, and his wife urged him to go to IU Methodist Hotel in Indianapolis to get his head and spine checked out.

Smith told SI that his head hit the court so hard that it left a giant bump on the back of his head.

Once at the hospital, Dr. Katie Trammel conducted several tests and found the cause: a pulmonary embolism.

Smith spent two days in the hospital and was discharged after blood thinners eliminated the clot.

According to SI and Doyel, Smith is back home in Kentucky with his family.

He plans to return to the hardwood for the 2021-22 season.