Moderna has engaged its own medical expert as it faces an inquest in Victoria, which is investigating whether a 21-year-old woman died because of its COVID-19 vaccine.
The pharmaceutical company's lawyers appeared before the Coroners Court in Melbourne on Wednesday for a hearing into the death of Natalie Boyce.
Ms Boyce received her third COVID-19 jab on February 18, 2022, which was the Moderna mRNA vaccine, counsel assisting Jessika Syrjanen told the court.
About a week later, she went to see a GP after vomiting for five days, suffering aching pain and at one point fainting.
In the following weeks, Ms Boyce went to hospital and a medical centre as her symptoms of vomiting, pain and fainting persisted.
On March 5, she went to Mulgrave Private Hospital, after suffering chest pain and shortness of breath, and was transferred to The Alfred where she was diagnosed with fulminant myocarditis.
The 21-year-old's condition deteriorated after she underwent surgery to remove a clot, then during an MRI she suffered a heart attack.
She could not be revived and Ms Boyce was declared dead on March 27.
A forensic pathologist performed a post-mortem on Ms Boyce, finding she died from acute myocarditis infarction.
The autopsy found "given the close proximity in time due to vaccine, a vaccine-related myocarditis cannot be excluded".
But the report also said this could not be diagnosed post-mortem.
In February this year, Moderna engaged its own cardiologist to provide an expert opinion to the court and asked for extended leave to provide a report from them.
Ms Syrjanen said Moderna's report differed to other medical evidence before the coroner on Ms Boyce's cause of death and medical management in the lead-up, but she did not detail how.
"Moderna submitted in a letter to the court that 'the conclusion from the autopsy report should be accepted: that a definitive cause for Ms Boyce's myocarditis cannot be identified'," she told the court.
"I seek clarification from Moderna's legal representatives today as to Moderna's current position and whether that has changed."
Moderna's lawyer Jesse Rudd said he could not give instant clarification on the company's position.
"That's the first I've heard of it," he replied, asking for time to seek advice.
All parties were given eight weeks to read through Moderna's report and consider their positions.
The case will return on July 17 for mention before Coroner Catherine Fitzgerald.
