THE world’s only licensed dengue vaccine should be restricted only to those with a documented past dengue infection, since the drug increases the risk of severe disease in people who have never had it before, World Health Organization (WHO) said in its latest position paper.
The WHO also recommended that patients who have received incomplete doses of Dengvaxia continue getting the vaccine shots because most of the population was likely to have already been exposed to dengue.
The agency also allayed fears of the severity of the dengue that would be contracted by those who had never had the disease before, saying all those who got the disease during the clinical trials survived.
It said there was “a significant benefit” in terms of reducing severe dengue and hospitalizations due to dengue with the use of the vaccine—if it is administered to a population that had largely been exposed to the disease.
However, “programatic and communication issues” should be taken into consideration in deciding on the continuation of a vaccination program, the WHO said.
The government suspended a massive school-based anti-dengue vaccination program in early December after the French manufacturer of the Dengvaxia vaccine, Sanofi Pasteur, said those who had no history of dengue faced the risk of more severe forms of the disease if they were inoculated.
Dengvaxia was introduced in the Philippines mainly through school-based programs and had a seroprevalence of 85 percent—he WHO said that “every one excess case within a five-year period of hospitalized dengue in vaccinated seronegatives [those who did not had a previous dengue infection]” will be offset by 18 cases prevented in vaccinated seropositives [those who had a previous dengue infection].”
Health Secretary Francisco Duque, who said the government would sue Sanofi, has yet to comment on the WHO statement.
The WHO position paper on the dengue vaccine replaces a question-and-answer document posted on Nov. 30.
But an independent panel of external experts is set to review the data in detail in April 2018.
Sanofi said it has asked drug regulators in all countries where Dengvaxia is either licensed or under evaluation for licensure to update the product’s label to instruct health care professionals to assess the likelihood of prior dengue infection before giving the vaccine.
The Health department had officially stopped the distribution of Dengvaxia after manufacturer Sanofi Pasteur revealed that its use needed to be limited as it could cause severe illness in individuals who have not had dengue prior to inoculation.
An estimated 830,000 students aged nine and older from public schools in Metro Manila, Central Luzon, Calabarzon, and Cebu have eceived the dengue vaccine.