Health dept suspends dengue immunization program over defective vaccine

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Health chiefs in the Philippines have suspended the country's dengue immunisation programme after the vaccine's manufacturer admitted it could cause severe cases of the disease in some people.

Use of Sanofi's dengue vaccine, the world's first approved shot against the mosquito-borne virus, is to be strictly limited due to evidence it can worsen the disease in people who have not previously been exposed to the infection.

Sanofi is requesting that health authorities update information on its dengue vaccine Dengvaxia, as a result of a new analysis of long-term clinical trial data, which found differences in vaccine performance based on prior dengue infection.

The said vaccine was used in the department's dengue vaccination initiative that was launched in three highly endemic regions (Regions 3, 4-A, and NCR), with over 700,000 individuals receiving at least one dose of the vaccine.

There are many factors that can lead to severe dengue infection.


Before the current analysis, a research team previous year found that the vaccine-if given to dengue-naïve individuals-"acts very much like a natural infection but without making recipients sick".

The minister said the government will profile all those who received the vaccination and heighten its surveillance mechanisms.

On Thursday, Sanofi Pasteur, the vaccines division of French multinational pharmaceutical company Sanofi, released its analysis confirming that "Dengvaxia provides persistent protective benefit against dengue fever in those who had prior infection...." That will include mandatory history-taking of those vaccinated, mandatory reporting of all vaccine recipients admitted to hospital regardless of symptoms, and five years of post-vaccination surveillance.

The company said it expected the new findings to cost it £88m. Dengue is different than most infectious diseases because a person's second infection is typically much more serious than the first.

The World Health Organization says that about half the world's population is at risk of dengue and estimates that about 96 million people are sickened by the viral infection every year.

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