3 global health challenges to watch in 2019

As 2019 begins, STAT reporters are taking a look at the stories they’re most eager to track during the year. Find all of our “three to watch” series here. 

Acouple years ago, the Zika virus startled the world with its until-then unrecognized ability to maim fetuses. A few years before that a camel virus — MERS — began infecting and killing people on the Arabian Peninsula. And a few years before that, H1N1 ignited the first flu pandemic in 41 years.

Does it kind of feel like we due for a new disease misadventure? Does Mother Nature have malign plans for 2019?

We have plenty of skills at STAT, but predicting the unpredictable is still out of our grasp. Know this, though: If some big new disease breaks out, we’ll be on top of it.

In the meantime, here are predictions we can make about some global health issues to watch in 2019.

Will the U.S. get a licensed dengue vaccine? Will Sanofi pocket a coveted prize?

Sanofi’s Dengvaxia has had a roller-coaster ride since it became the first dengue vaccine to reach the market in 2016. Dengue places a major strain on the health systems of countries where it circulates and the vaccine was quickly licensed by 20 of them.

Late in 2017, the company announced it had discovered a problem some dengue experts had predicted could materialize with this vaccine. While it lowered the risk of hospitalization for severe dengue infection in children who had already had at least one bout of the disease, it actually elevated the risk for children who were vaccinated before ever having dengue.

In the Philippines, which had rolled out the vaccine broadly, its use was suspended and the country has threatened legal action. There have been reports that public confidence in all vaccines there has plummeted in the wake of the controversy.

Experts who advise the World Health Organization recommended the vaccine be given only to children who have been previously infected with dengue. But there isn’t currently a point-of-care rapid test available for prior infection and having to test before vaccination really complicates mass vaccination efforts.

Despite this setback, Sanofi has applied to the Food and Drug Administration for a license to sell the vaccine in the United States. Given that most Americans have not been infected with dengue, the U.S. market would currently seem to offer modest — at best — prospects for Dengvaxia. The company cited U.S. offshore territories such as Puerto Rico, where dengue circulates, to explain the application. (The vaccine was recently licensed in Europe for use in people who have had a documented prior dengue infection and who live in an area where dengue circulates.)

Others think there’s another prize in the company’s sights. Dengue is on a list of neglected diseases that the FDA encourages pharmaceutical companies to work on. Companies that bring to market a new drug or vaccine targeting these diseases earn a priority review voucher, which entitles a company to expedited FDA review of a future drug or vaccine submission.