Preliminary report outlines 'causal association' between Sanofi's Dengvaxia and 3 deaths

Sanofi maintained that its vaccine has never directly been linked to any deaths. (Sanofi on Flickr)

After months of controversy in the Philippines over Sanofi's Dengvaxia, an initial report has found a "causal association" between three deaths and the vaccine. Two of the deaths could have been a result of vaccine failure, according to the Philippine General Hospital report. 

"Further analysis of tissue samples will be required to complete the investigation," the PGH press release states, according to a translation by Google. 

A Sanofi spokesperson said the report confirmed "that there is currently no evidence directly linking the Dengvaxia vaccine to any of the 14 deaths." 

"In Dengvaxia 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's spokesperson added. 

The Philippines has been probing the vaccine—plus the government's decision to implement a mass vaccination program—ever since Sanofi last year disclosed its shot can cause more serious infections if given to people who haven't had a prior infection. 

That's because the shot can act as a natural first infection and for people who get the infected a second time, dengue can be much more serious, according to a 2016 study published in Science. 

The Friday press release said the finding "affirms the department's decision to stop the Dengue Immunization Program because Dengvaxia should not be implemented under a mass immunization program" that doesn't evaluate whether recipients have already had an infection. 

However, Dengvaxia can still provide meaningful protection for those with prior exposure, the drugmaker contends. 

The company's spokesperson added that evidence confirms "dengue vaccination in the Philippines will provide a net reduction in dengue disease, including severe dengue and, thereby, reduce the overall public health burden associated with this disease." 

During the scandal, Sanofi has agreed to refund the Philippines for unused shots and to pay for Dengvaxia adverse events that are scientifically proven to be caused by the vaccine. 

But even more recently, the country's health authority asked for a full refund for the $70 million vaccine program. Sanofi said it will respond to the request "in the coming days."

Sanofi spent $1.5 billion and 20 years developing the world's first dengue vaccine. But now, it isn't making any new shots, according to the spokesperson, "as our inventories are sufficient for the years to come." 

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."