After Dengvaxia scandal spooks parents, experts warn of measles threat in Philippines

Sanofi disclosed in November 2017 that Dengvaxia can cause more serious infections if given to people who haven't had a prior exposure to dengue. (Sanofi)

Since Sanofi disclosed that its dengue vaccine Dengvaxia can cause more serious infections in certain people, distrust in vaccines has mounted in the Philippines, and now experts are raising red flags about possible measles outbreaks in the country. 

The World Health Organization reported that measles cases in the Philippines grew fivefold to more than 17,000 in the 11 months leading up to November, compared with the same period last year, Reuters reported. Speaking with reporters, Lulu Bravo, executive director of the Philippine Foundation for Vaccination, said the growth stemmed from a lower trust in vaccines, according to the news service. 

And part of the trust problem is rooted in the Dengvaxia safety scandal and ensuing political response, officials say. Sanofi’s vaccine was part of a national campaign before the company disclosed it can cause more serious cases if given to patients without a prior dengue infection.

After that November 2017 announcement, officials in the Philippines canceled vaccinations, asked for a refund and kicked off investigations.

In all, the episode cost Sanofi €158 million last year—and put a damper on enthusiasm for immunizations, experts have said, citing new survey data.

RELATED: After Philippines safety scandal, Sanofi's Dengvaxia set for European approval 

Last month, a team led by the London School of Hygiene & Tropical Medicine reported that only 32% of participants in a 1,500-person survey said they strongly agreed that vaccines are important, down from 93% in 2015.

In many countries, authorities simply updated their usage guidelines for the vaccine after Sanofi made its update, the experts noted. In the Philippines, however, response to the disclosure became highly politicized.

RELATED: Sanofi's dengue shot Dengvaxia wins FDA priority review despite controversial past 

Even after the controversy—and disappointing early sales figures—Sanofi isn’t giving up on its vaccine. In October, Dengvaxia won expert backing for approval in Europe and is likely set for a nod there by the end of the year. The same month, the vaccine won priority review from the U.S. FDA. With an FDA approval, officials could use the vaccine in the U.S. Virgin Islands and Puerto Rico, where the dengue burden is high, according to the company.  

Dengvaxia carried high initial sales expectations after Sanofi spent $1.5 billion and 20 years developing the shot. But in 2016, Dengvaxia's first year on the market, the vaccine generated €55 million in sales. In 2017, sales sank to just €3 million. As Sanofi presses ahead with the shot, Takeda is testing a potential rival in phase 3.