Tuesday, December 05, 2017

Philippines: FDA Withdraws Dengvaxia® Vaccine - Sanofi Quantifies Risk


The controversy, and finger pointing, over the suspension of Sanofi's Dengvaxia® vaccine in the Philippines last week after a safety signal was announced continues to escalate, with the drug manufacturer downplaying the risks, and local media and local politicians calling the vaccination of hundreds of thousands of children with this product a `fiasco'.
This safety signal only involved children who had never been infected with dengue who received the vaccine, a number which has been estimated to be about 10% of the 700,000+ recipients in the Philippines. Recent studies suggest they are at an increased risk of seeing a `severe dengue infection' months or years later.
The World Health Organization has promised `a full review of the data through the Global Advisory Committee on Vaccine Safety and SAGE, for revised guidance of the use of Dengvaxia®', while Brazil's ANVISA has recommended restrictions on its use until more is known.
While the Philippines DOH temporarily suspended the administration of the vaccine on Friday, yesterday their FDA issued the following order to withdraw the product from the market.

FDA Advisory No. 2017-318 || Suspension of Sale/Marketing/Distribution of Sanofi Pasteur, Inc.’s Tetravalent Vaccine (Live, Attenuated)(Dengvaxia)

On 29 November 2017, Sanofi Pasteur, Inc. (Sanofi) released an advisory providing updated information on the Dengue Tetravalent Vaccine (Live, Attenuated), the drug locally registered as Dengvaxia. The advisory contained information on the completion of a post-clinical trial study of the said product indicating potential risk to patients who have not had dengue prior to immunization.

In order to protect the general public, the Food and Drug Administration (FDA) immediately directed Sanofi to SUSPEND the sale/distribution/marketing of Dengvaxia and cause the WITHDRAWAL of Dengvaxia in the market pending compliance with the directives of the FDA. Sanofi was further directed to conduct an information dissemination campaign through Advisories, Dear Doctor Letters and Patient fora.

The FDA is closely coordinating with the Department of Health (DOH) for any adverse events/ reactions that may be reported by the recipients following their immunization of the Dengvaxia, and will immediately take appropriate measures to protect the public.

All drug establishments, including consumers and non-consumer user (e.g. healthcare professionals) are enjoined to take part in the post marketing surveillance of Dengvaxia, by reporting to FDA any incident that reasonably indicates that Dengvaxia has caused or contributed to the death, serious illness, or serious injury to a consumer, a patient, or any person. 

FDA Advisory No. 2017-318.pdf

Sanofi, meanwhile, has issued another information update on the recently revealed safety signal, which attempts to quantify the risks of developing severe illness as a result of a dengue naive individual receiving the vaccine.
They put that risk at ` 2 additional cases of “severe dengue” out of 1000 previously dengue-uninfected people vaccinated over 5 years of follow-up.'
Follow the link below to read the press release in its entirety.  
December 4, 2017
Information update on Dengvaxia

For those who did not have previous dengue infection before vaccination, the vaccine does not cause dengue. 5  
Furthermore severe Dengue infections are rare; it is estimated that only 1 in 800 of all dengue infections (including symptomless infections) could lead to a severe infection, 2 and the increased risk identified from the new analysis translated to 2 additional cases of “severe dengue” out of 1000 previously dengue-uninfected people vaccinated over 5 years of follow-up. Please note that the definition of “severe dengue” used in the clinical trials was a wider definition than the definition in countries that follow the WHO’s 2009 criteria, and out of the very few cases of severe Dengue in a group of around 18.000 people vaccinated in the clinical trials, all fully recovered. 4

(Continue . . . )

Between parents understandably worried about the potential long-term health impacts to their kids, politicians either running for cover or using this as a political weapon - and no lack of hyperbolic press coverage - this is quickly becoming a cause célèbre, whose impact on the public's acceptance of new vaccines may be its biggest and most lamentable legacy. 

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