Lending fuel to the ongoing controversy in the Philippines over the possible side effects of Sanofi Pasteur 's Dengue vaccine Dengvaxia, an initial report by the Philippine General Hospital (PGH) has found a "causal association" between three deaths and the vaccine.

PGH said it will submit its report to the Philippine Department of Justice "to assist with their ongoing investigation and identify those who are responsible if they prove to be in violation of the law."

The hospital said two of the deaths could have been a result of vaccine failure, while cautioning that further analysis of tissue samples will be required to complete the investigation.

Sanofi said, however, the report confirms "that there is currently no evidence directly linking Dengvaxia to any of the 14 deaths.

“In clinical trials conducted over more than a decade and the over one million doses of the vaccine administered, no deaths related to the vaccine have been reported to us," the company said.

Under pressure from the government, the French vaccines producer has agreed to refund the country $28 million for unused doses of the vaccine. The Senate of the Philippines is holding hearings into the matter.

According to a 2016 study published in the journal Science – which Sanofi has acknowledged – infections resulting from the vaccine can be more serious in those who haven’t had a previous vaccine.

In December 2017, more than 70 families of children receiving the Sanofi vaccine filed for criminal prosecution of former government officials, including ex-President Benigno Aquino III, former Department of Health (DOH) chief Janette Garin and two other government officials, as well as five Sanofi executives including CEO Olivier Brandicourt and Asia-Pacific head Thomas Triomphe.

By its own account, Sanofi spent $1.5 billion and 20 years developing the world's first dengue vaccine. The company at present is not producing the vaccine, as it said inventories are sufficient.