EPIDEMIC
OF FE AR
DENGUE’S RELENTLESS RISE
110
FORTUNE.COM // DECEMBER 2019
dengue vaccine, Dengvaxia, had been admin-
istered, it was just after midnight on Nov. 30.
Twenty months earlier, the Philippines had
proudly been the first country to launch a
public immunization program involving Sano-
fi’s vaccine, boldly taking aim at a disease that
perennially caused agony for its citizens and
taxed its overburdened health care system.
Dengvaxia, which the Filipino government
gave to roughly 890,000 children, had been
feted globally as a public health triumph. The
development of Sanofi’s vaccine was as com-
plicated and technically challenging as they
come. And it was the culmination of a broader
effort that spanned decades and took billions
of public and private dollars. Plus, in an ad-
mirably altruistic inversion of the Big Pharma
playbook, the vaccine was being delivered first
not to the rich Western countries that could
pay the most but to a poorer one that needed
it more. It was a story to celebrate.
But here in Sanofi’s press release, buried
in the middle of a dense paragraph of highly
technical language, was a sentence that would
surely give anyone in the Philippines pause:
“For those not previously infected by den-
gue virus, however, the analysis found that in
the longer term, more cases of severe disease
could occur following vaccination upon a
subsequent dengue infection.” In other words,
there were some people who wouldn’t be pro-
tected from dengue by Dengvaxia. In fact, the
opposite: It put them at risk for getting sicker.
The statement, which Sanofi had sweated
over and planned around for days, lacked
context, local or otherwise. It didn’t offer prob-
abilities or degrees of risk; it didn’t explain
what “severe dengue” meant, or give people in
the Philippines or Brazil, where another mass
immunization drive was underway, or in any of
the other 15 countries where Dengvaxia was li-
censed, any clue how worried they should be. It
just recommended that people who had never
previously had dengue not get the vaccine.
That was the moment the Dengvaxia fiasco
began. It was also a fiasco foretold. While the
vaccine had many boosters, a handful of sci-
entists saw problems ahead. The most vocal of
the critics was one of Sanofi’s own consultants,
who warned the world that the vaccine would
work—but only with a critical asterisk that
health officials and the public needed to under-
stand. Which meant the news that jolted the
Philippines into a spiraling calamity on Nov. 30
was, among researchers, the subject of ongoing
study and a much-discussed possibility.
“It seemed like a surprise, though it wasn’t
a surprise,” says In-Kyu Yoon, a senior adviser
for the International Vaccine Institute.
“The communication around this was dif-
ficult,” says Gundo Weiler, a director with the
World Health Organization (WHO) based in
Manila. The intricacies of vaccine science and
dengue, especially in an environment of fear,
he adds, “are not so easy to understand—that
was the problem of the whole situation.”
Eric Domingo, who serves as undersecretary
for the Department of Health of the Philip-
pines, sums up the Dengvaxia tale best of all:
“It just turned into this gigantic monster,” he
tells Fortune. But what’s truly frightening is
how quickly this monster formed, and how eas-
ily. What happened to Dengvaxia could happen
to any imperfect medical innovation in the age
of social media—for here, in the emotional gyre
of politics, anxiety, and misinformation, the
rational questions and doubts of science can
quickly be branded as crimes and conspiracies.
Nothing about the development or admin-
istration of Dengvaxia was intentionally reck-
less, it should be said—though its story does
contain elements of hubris, blind optimism,
and questionable haste.
That was clear from the start, when Chris
Viehbacher became CEO of Sanofi in Decem-
ber 2008. Almost right away, he green-lit the2.39 MILLION
0
0.5
1.0
1.5
2.0
2.5 million