The Philippine Food and Drug Association says drugmaker Sanofi (SNY)  knew that its dengue fever vaccine was dangerous to people who had never had the disease, since in 2015, but failed to inform the government when it applied for drug approval in Singapore.

Sanofi's drug was approved on Dec. 22, 2015, but the company only advised of the vaccine's limitations in November 2017. 

The Philippine government suspended the school-based dengue fever immunization program in December 2017 after the French vaccine maker stated that the vaccine could cause more severe cases of dengue if administered to people who hadn't had the disease prior. 

The program ended up costing the Philippine government $67 million. More than 700,000 children ages 9 and above were given their first dose of the vaccine as of November 2017. 

A Philippine lawmaker estimated that 90% of patients who sought medical assistance at the drug's rollout turned out to be negative for the disease. 

Sanofi shares were rising in afternoon trading Monday, up 0.77% to $40.44. 

More from Stocks

Dow Tumbles Triple-Digits as IBM Slumps

Dow Tumbles Triple-Digits as IBM Slumps

WATCH at 11 a.m. ET: Cramer, Canopy Growth's CEO and Constellation Brands' COO

WATCH at 11 a.m. ET: Cramer, Canopy Growth's CEO and Constellation Brands' COO

Tesla's China Gigafactory Is Closer to Reality After Securing 210-Acre Plot

Tesla's China Gigafactory Is Closer to Reality After Securing 210-Acre Plot

Applied Materials Is Still Bearish, Looks Headed Lower in the Months Ahead

Applied Materials Is Still Bearish, Looks Headed Lower in the Months Ahead

Applied Materials Continues to Rise as Analysts Debate Outlook

Applied Materials Continues to Rise as Analysts Debate Outlook