LETTER | With the dengue vaccine Dengvaxia, it is the opposite of the tagline, ‘benefit outweighs harm’, often used in vaccines and medications.

On Nov 29, the French pharmaceutical giant Sanofi-Pasteur, which is the manufacturer of the vaccine, made a shocking announcement – ‘Sanofi updates information on dengue vaccine’. The statement is ambiguous, self-contradictory, and seems more of a damage-control exercise.

The statement, based on  clinical data gathered over six years, highlighted two points:

• Dengvaxia provides persistent benefit against dengue fever in those who had prior infections.
• For those not previously infected by the dengue virus, more severe cases of the disease could occur following vaccination if they have a subsequent dengue infection.

Dissecting the Sanofi-Pasteur’s statement and to help the laymen better understand this important health subject matter, Persatuan Patriot Kebangsaan would like to make the following comments:

First, recovery from infection by one dengue virus provides lifelong immunity against that particular virus serotype. There are in total four serotypes for dengue.

A person can only get infected with dengue a maximum of four times. But the serotype found to be most common was the DENV-3, of which the vaccine was supposed to give protection. Hence, it was dishonest of the pharmaceutical giant to imply the vaccine gave protection and claim credit for what nature had intended.

Second, for those who are seronegative, meaning they have never been infected by any of the four serotypes, if they are given the dengue vaccine and later on infected with dengue, they could produce a more severe disease condition than if they had not been given the vaccine. Herein lies the argument for the harm outweighing the benefits.

As early as Sept 2016 there have been reports of more hospitalisation for severe adverse events due to the administration of Dengvaxia.

Despite alarm bells, the Ministry of Health in Nov 2016 proceeded to grant a two-year conditional registration approval for Phase IV clinical trials as reported by Bernama. Phase IV clinical trials are meant for testing of the product on healthy males before full-scale marketing is allowed.

We urge the MOH, especially those officials responsible for drugs and vaccines registration, to be extra vigilant and to seriously study research documents prior to their approval. The health of our people ranks supreme and officials on the government payroll owe it to the people to execute their responsibilities well.

We would also like to take this opportunity to ask MOH what has been the outcome of the project to release genetically engineered mosquitoes at Pulau Ketam three years ago, as a means to control dengue.

The views expressed here are those of the author/contributor and do not necessarily represent the views of Malaysiakini.