Wednesday, December 13, 2017

Sanofi Dengue Vaccine Fallout Continues


It's been not quite two weeks since the announcement by the Philipppine DOH of the suspension of their dengue vaccination campaign vaccine (primarily aimed at school-aged children) following an advisory issued by Sanofi of safety concerns when Dengvaxia® is administered to someone who has never had dengue before. 
This comes after more than 800,000 children had received at least one dose of the vaccine, and estimates that as many as 10% were dengue-naive at the time. 
Within days the Philippines FDA withdrew the drug from the market, and while Sanofi has since quantified and downplayed the risks (see Dec 4th Information update on Dengvaxia), concerns over long-term effects on thousands of vaccinated children linger.

As we've discussed previously, there have long been concerns over the safety of the dengue vaccine, particularly in regards to a phenomenon called antibody dependent enhancement or ADE.

Generally speaking, a person's first infection with dengue is relatively mild, but with four serotypes, a person can be infected multiple times during their lifetime. A person's second infection with dengue is often more severe due to the body thinking the second infection is the same serotype as the first, and sending inefficient antibodies to fight it.
When given to a dengue-naive individual, the dengue vaccine can substitute for that first infection, and could make a later infection worse. 
Despite concerns published in reputable journals, and a `conditional' approval by the World Health Organization, the decision was made to move forward with a mass vaccination program in the Philippines.

Adding fuel to the fire, in early November a paper was published in the Journal of Clinical Epidemiology that openly questioned the methodology of safety trial meta-analyses used for the vaccine with the provocative title:
Review of a licensed dengue vaccine: Inappropriate subgroup analyses and selective reporting may cause harm in mass vaccination programs
Antonio L. Dans, MD, MSc1,Leonila F. Dans, MD, MSc1,Mary Ann D. Lansang, MD, MMedSc1,Maria Asuncion A. Silvestre, MD2,Gordon H. Guyatt, MD, MSc3

While it still isn't clear how much of a health risk is posed by the vaccination of dengue-naive individuals, the political fallout, and public fear is unmistakable. The Philippines has launched a Senate investigation, there are charges (as yet unproven) of collusion between the MOH and Sanofi, a lot of finger-pointing and head-ducking, and talk of law suits.

Over the past couple of days, the media - both in the Philippines and Internationally - has ratcheted up their coverage, with Reuters in particular weighing in.  A few examples:
EXCLUSIVE-Philippines defied experts' advice in pursuing dengue immunisation programme 
by Reuters
Monday, 11 December 2017 03:30 GMT
Did Sanofi, WHO ignore warning signals on dengue vaccine?

Julie Steenhuysen and Ben Hirschler, Reuters
Posted at Dec 13 2017 12:19 PM
Both reports are well worth reading in their entirety, and will do little to help defuse the situation. Words like `scandal', `debacle', and `fiasco' are all flying in the press over this flap, with no end in sight.

Regardless of the actual risk of injury from this vaccine (which is still under investigation), Dengvaxia's reputation - and the reputation of other vaccines - has been significantly tarnished.

I'm already hearing push back from vaccine skeptics, and headlines in today's SunStar paper reflect the reality of the fallout.
Wednesday, December 13, 2017 By Erwin P. Nicavera 
THE Department of Health (DOH) in Western Visayas called on the public to still trust other vaccines given by the government for free despite the Dengvaxia scare.
         (Continue . . . )
Despite having the benefit of being true, that's a message that is likely to become much harder to sell to the public going forward.

And sadly, that will probably cost a lot of lives.

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