About 733,713 Filipino children have been given the dengue vaccine as of November 2017. Sanofi Pasteur stressed that the vaccine still protected against dengue fever when it was given to people who had prior dengue infections. While Sanofi's Dengvaxia is the first-ever approved vaccine for dengue, scientists already recognised it was not flawless and did not protect equally against the four different types of the virus in clinical tests. The Department of Health (DOH) halted on Friday the use of a dengue vaccine made by Sanofi after the company said its use must be strictly limited due to evidence it can worsen the disease in people who have not previously been exposed to the infection.
For now its mass vaccination programme - which was focused on areas where dengue was already widespread - has been suspended and hospital records are being checked for severe cases of the disease.
THE Philippines is prepared for a "worst-case scenario" after warnings that a vaccine against dengue fever could cause symptoms of the disease to become more severe.
According to Presidential spokesperson Harry Roque, those behind the program will be held responsible and that the Department of Health (DOH) is now closely monitoring those who have received the vaccine.
Sanofi Pasteur disclosed Wednesday that vaccine Dengvaxia should not be given to individuals who have never been infected with the dengue virus.
Despite the suspension, Duque said "vaccination is essential to the integrated approach in dengue prevention and control". The Philippines meanwhile participated in all three phases of the clinical trials for the vaccine.
The WHO said in a statement that in the light of the new findings, "as a precautionary and interim measure, WHO recommends that Dengvaxia is only administered to subjects that are known to have been infected with dengue prior to vaccination".
Dr. Julius Lecciones, director of the Philippine Children's Medical Center, said they had also received no reports of severe illness from Brazil, another country that has used the vaccine on a wide scale.
Senator JV Ejercito, chair of the Senate health committee, said he would open an inquiry into the program after health authorities finished their own investigation of the dangers posed by the Dengvaxia.
Jiamsiri said Thai health agencies had planned on consulting with WHO experts on the matter.
Out of more than 211,000 suspected cases of dengue fever in the Philippines past year, at least 1000 people had died, according to government figures.