In spite of the controversy around it, I consider the development of Sanofi Pasteur’s Dengvaxia® (CYD-TDV), the world’s first dengue vaccine, a technological success. According to the World Health Organization (WHO, 2017), dengue, a mosquito-borne viral infection, has become more prevalent in the recent decades. It is estimated that 3.
9 billion people around the world are now at risk of contracting the potentially deadly virus. There is, clearly, an urgent need for preventive interventions against the disease, and Dengvaxia®, along with several other dengue vaccines in development, is a response to that need. In its interim interpretation, the WHO (2017) stated that Dengvaxia® “significantly protects against hospitalized and severe dengue in individuals seropositive for dengue at the time of first vaccination in all age groups studied.” This interim interpretation was later reaffirmed by the results of the additional analyses that were conducted by Sanofi Pasteur: “…overall, vaccinated trial participants had a reduced risk of virologically-confirmed severe dengue and hospitalizations due to dengue” (WHO, 2017). It is my belief that the focus should be on the aforementioned facts.
The unfortunate situation in the Philippines involving Dengvaxia® appears to be the consequence of the premature sale, distribution, and marketing of Sanofi Pasteur and the premature purchase and procurement and improper dispensation and administration of our government.Prior to the start of the government’s school-based dengue immunization program, the WHO cautioned that “there is a theoretical possibility that vaccination may be ineffective or may even increase the risk of severe and/or hospitalized dengue in those who are seronegative at the time of first vaccination, regardless of age” (Sage Group & WHO Secretariat, 2016, p.33).
Yet, notwithstanding the warnings given by the WHO and by notable figures in the healthcare industry including Dr. Antonio L. Dans, Dr.
Leonila F. Dans (Gutierrez, 2017), and Dr. Scott Halstead (Steenhuysen & Hirschler, 2017), the Department of Health continued on with their school-based dengue immunization program.In a recent interview, Dr. Francisco Duque III, the Secretary of the Department of Health, said that the school-based dengue immunization program should have been postponed until the results of the six-year study period for the Phase 3 clinical trials have been released (Jaymalin, 2018). The results, which were released late last year, confirmed the concerns: Dengvaxia® should not be administered to seronegatives.The fallout that resulted from the errors of judgement of Sanofi Pasteur and our government should not detract from the fact that Dengvaxia® provides seropositive individuals protection against severe dengue and reduces their hospitalizations due to dengue.
However, it is regrettable that the damage appears to have already been done.The unfortunate situation in the Philippines has spread fear and panic among the people, as well as distrust and disbelief in our government and in our health officials, and suspicion and skepticism towards the healthcare and pharmaceutical industries. Worse, this sets the stage for a rise in the number of vaccine-preventable diseases.
Dengvaxia® is not a perfect vaccine for “there is no such thing as a ‘perfect’ vaccine which protects everyone who receives it AND is entirely safe for everyone” (WHO, 2014). However, its development, as well as future research and studies, would only lead to better and more effective dengue vaccines—which, perhaps, would one day ultimately lead to the complete eradication of dengue.