A West Australian woman who suffered a rare blood clot after receiving the AstraZeneca COVID-19 vaccine is recovering well after a period in intensive care.

The woman in her 40s presented at the emergency department of a regional WA hospital about a fortnight after receiving the jab in mid-March. She was then flown to Royal Darwin Hospital where she was admitted to intensive care.

She is now in a stable condition.

"Her family has authorised us to say that her progress has been very positive and that she is recovering well," WA Health Minister Roger Cook told reporters on Tuesday.

A 44-year-old Melbourne man also developed the condition following his AstraZeneca vaccination last month.

People who have received the vaccine have been asked to look out for symptoms including severe or persistent headaches, blurred vision, shortness of breath, chest pain, leg swelling, abdominal pain or unusual bruising.

About 700,000 doses of AstraZeneca vaccines have been administered in Australia, so the two cases equate to a frequency of one in every 350,000 people.

The Pfizer jab is now the preferred option for people under the age of 50.

But Mr Cook said anyone under 50 in WA will still be able to request the more widely available AstraZeneca vaccine once informed consent arrangements are finalised.

"We can't continue to believe that we are immune from this global pandemic," he said.

"We have to make sure that we can step forward in this vaccination program as part of a global effort to make everyone safe. Otherwise we're just sitting ducks."

A crew member from a bulk iron ore carrier docked off the coast of WA is meanwhile in a stable condition after being hospitalised in Perth.

The man in his 50s became unwell last week while aboard the AquaGenie vessel in Commonwealth waters off the coast of Karratha.

A boat was sent to retrieve the man, who is now in a negative pressure room at Royal Perth Hospital after initially being taken to Karratha Health Campus.

Mr Cook said there were no reports of illness among the remaining 23 crew.

A legal direction has been issued blocking the ship from entering WA waters and it is expected to return to the Philippines in coming days.