Rush To Produce, Sell Vaccine Put Kids In Philippines At Risk
May 3, 2019
Scott Halstead, who has studied dengue for more than 50 years with the U.S. military. When Halstead looked at the vaccine's safety data in the clinical trial, he knew right away there was a problem.
For some children, the vaccine didn't seem to work. In fact, Halstead says, it appeared to be harmful. When those kids caught dengue after being vaccinated, the vaccine appeared to worsen the disease in some instances. Specifically, for children who had never been exposed to dengue, the vaccine seemed to increase the risk of a deadly complication called plasma leakage syndrome, in which blood vessels start to leak the yellow fluid of the blood.
Here's the problem with Dengvaxia.
Typically, a vaccine works by triggering the immune system to make antibodies against the virus. These antibodies then fight off the virus during an infection.
But dengue is a tricky virus. Dengue antibodies don't always protect a person. In fact, these antibodies can make an infection worse. The dengue virus actually uses the antibodies to help it spread through the body. So a second infection with dengue — when your blood already has antibodies in it — can actually be worse than the first; a person is at a higher risk of severe complications like plasma leakage syndrome.
"I just think, 'No, you can't give a vaccine to a perfectly normal, healthy person and then put them at an increased risk for the rest of their lives for plasma leakage syndrome,' " Halstead says. "You can't do that."
The vaccine manufacturer disagreed with Halstead's interpretation of the study's results. The company wrote a rebuttal, asserting that regulatory agencies had approved Dengvaxia "on the basis of the vaccine's proven protection and acceptable safety profile."
In November 2017, Sanofi published an announcement on its website saying it had new information about Dengvaxia's safety.
Halstead's fears were confirmed. Sanofi had found evidence that the vaccine increases the risk of hospitalization and cytoplasmic leakage syndrome in children who had no prior exposure to dengue, regardless of age.
"For individuals who have not been previously infected by dengue virus, vaccination should not be recommended," the company wrote.
In total, the deaths of about 600 children who received Dengvaxia are under investigation by the Public Attorney's Office
https://www.npr.org/sections/goatsandsoda/2019/05/03/719037789/botched-vaccine-launch-has-deadly-repercussions