VANCOUVER -- B.C. medical experts are reassuring the public that the AstraZeneca COVID-19 vaccine is still safe after the province recorded its second case of blood clots linked to the shot.

Provincial health officer Dr. Bonnie Henry revealed Thursday the case was a man in his 40s, adding he was “in stable condition receiving treatment in the Fraser Health region.”

The man has revealed himself to be Langley father Shaun Mulldoon. In a public Facebook post, Mulldoon says doctors found a “massive blood clot” 17 days after he received the AstraZeneca vaccine.

“Ended up going into emergency surgery to remove over 6 feet of my small intestine,” Mulldoon’s post says.

A friend of Mulldoon told CTV News Vancouver his family was not ready to speak to the media.

CTV News spoke with B.C. medical experts about the AstraZeneca vaccine and the rare disorder now linked to it.

What is VITT?

The condition is called vaccine-induced thrombotic thrombocytopenia (VITT). Dr. Anna Wolak, a family physician in Vancouver, told CTV News in an interview it causes blood clots “wherever there are blood vessels, so basically that’s all over your body.”

“When we’re looking for signs from head to toe, we look at things like headaches, signs of a stroke, paralysis, blindness … chest pain, shortness of breath,” Wolak said. “There could be blood clots in the intestines, so if you have severe abdominal pain … We also look at your limbs.”

Wolak adds there are tests to see if a patient has developed VITT, and treatment is available through medication in a hospital.

How rare is it?

The provincial health officer has previously said VITT happens in about 1 in 100,000 doses. Dr. Brian Conway, medical director of the Vancouver Infectious Disease Centre, says that risk is “a little higher than we had initially thought.”

“When it was first reported it was about one in a million,” Conway said, adding he believes it now to be “probably closer to one in 55,000.”

He said the chances of a patient developing VITT decline on the second dose.

“If you did well with the first shot, the risk of blood clot or any serious side effect with a second shot is exceedingly low, one in a million or even less,” Dr. Conway said.

This week, the province announced it would only be using AstraZeneca for second doses moving forward.

Is AstraZeneca safe?

Dr. Ismael Samudio is a Vancouver immunologist and founder of Immunity Diagnostics Inc.

When asked if he believes the vaccine is safe, he responded: “Absolutely, in fact, full transparency, I registered at five different pharmacies to try to get the AstraZeneca shot.”

“The vaccine is old-school technology,” Samudio explained. “You take a virus and you make it look like SARS-COV 2. So when it arrives, your immune system sees it’s a virus. And that’s what the immune system knows very well, viruses and pathogens.”

Both the AstraZeneca and Johnson & Johnson vaccines use this method. They are known as viral-vector vaccines, while the Moderna and Pfizer-BioNTech vaccines use new technology known as messenger RNA.

What to do if you’ve received AstraZeneca?

The B.C. Centre for Disease Control recommends monitoring for symptoms between four and 28 days after receiving the AstraZeneca shot. If any symptoms develop, call 811 or seek medical attention right away.