A new study that analyzed the coronavirus outbreak in Brazil found a link between the spread of the virus and past outbreaks of dengue fever that suggests exposure to the mosquito-transmitted illness may provide some level of immunity against Covid-19.

Takeda Pharmaceutical Co.’s experimental dengue vaccine was highly effective at preventing the mosquito-borne disease in a late stage study, but TAK-003 failed to protect against one type of the virus in people with no prior exposure to dengue.

Prior infection with dengue, a mosquito-borne disease that infects nearly 400 million people a year, could reduce the risk of contracting Zika nearly by half, U.S. and Brazilian researchers reported.

Takeda Pharmaceutical’s experimental dengue vaccine appears to be safe and effective at preventing all four types of the mosquito-borne disease, meeting the main goal of a late-stage clinical trial.

Sanofi management expressed confidence that the company’s pipeline of new products will support long-term growth.

The Philippines will seek the return of 3 billion pesos ($59 million) it paid French drugmaker Sanofi for a dengue vaccine used to immunize hundreds of thousands of children that Sanofi has said could worsen the disease in some cases.

The Philippines has ordered French drugmaker Sanofi to stop the sale, distribution and marketing of its Dengvaxia dengue vaccine in the country.

The Philippines ordered a probe on Monday into the immunization of more than 730,000 children with a vaccine for dengue that has been suspended following an announcement by the French drug company Sanofi that it could worsen the disease in some cases.

Sanofi SA ended development of an experimental vaccine for Clostridium difficile infection.

Use of Sanofi’s dengue vaccine, the world’s first approved shot against the mosquito-borne virus, is to be strictly limited due to evidence it can worsen the disease in people who have not previously been exposed to the infection.