Dr Brenda Fitzgerald, director of the US Centers for Disease Control and Prevention, held “certain complex financial interests” that she could not sell in time.
Sanofi revealed last year that Dengvaxia, its dengue vaccine, might increase the risk of severe disease in people who had never been exposed to the virus.
The CDC said its travel notice for Puerto Rico remains in place and that it expects the Zika virus will continue to “circulate indefinitely” in most regions where it has been introduced.
The researchers found that the HIV virus first jumped from the Caribbean to New York City around 1970, triggering the North American epidemic.
The public health emergency declaration is a tool for the federal government to provide fresh support to Puerto Rico’s government to tackle the outbreak and grants access to certain federal funds.