Those at risk are some 70,000 children who were vaccinated under a Health Department program since 2016.
“In the light of this new analysis, the DOH will place the dengue vaccination program on hold while review and consultation are ongoing with experts and key stakeholders and the WHO (World Health Organization), Health Secretary Francisco Duque III said in a media briefing on Friday.
Duque said 733,713 children from Central Luzon, the region of Cavite, Laguna, Batangas, Rizal, and Quezon, and Metro Manila were administered Dengvaxia. Eight to 10 percent or about 70,000 children have not had dengue yet, the DOH added.
Pharmaceutical company Sanofi on Wednesday said new clinical data analysis showed those not previously infected with dengue and got vaccinated with Dengvaxia could contract “severe disease”.
“For those not previously infected by dengue virus, however, the analysis found that in the longer term, more cases of severe disease could occur following vaccination upon a subsequent dengue infection,” it said.
Sanofi maintained that it provided protection against dengue fever to those who had been infected before.
According to Sanofi’s study, Duque said the vaccine will prevent severe illness for at least 30 months, regardless if a person contracted the infection or not. But in the long term, “severe cases may occur” for those who never were infected by the mosquito-borne virus.
The World Health Organization recommended the use of Dengvaxia in 2016 in areas where dengue is highly endemic based on information available from Sanofi that time.
The Food and Drug Administration (FDA) said Dengvaxia underwent clinical trials to ensure safety and efficacy.
“It will not get an FDA approval if the documents are not complete,” FDA Director Dr. Benjamin Co said.
He said there were no reported cases yet of severe illnesses from those who received the vaccination.
Health officials said they will profile those who got the vaccine and impose a five-year post-vaccination surveillance.
“Although sinabi nating 30 months ang protection, we will heighten our surveillance activities,” Duque said.
Duque said they have fully paid Sanofi for the vaccines. The Health Department spent P3.5 billion for the immunization program, a move questioned by some doctors as Dengvaxia was not yet been approved by the World Health Organization.
To date, there are still almost 800,000 doses that have not been used, amounting to almost 800 million pesos, most of which will expire in August 2018.
Senator Richard Gordon raised the issue that the vaccine was not tested on a small group.
“WHO has warned that the vaccine had not been given pre-qualification approval as it had not yet been tested on at least 200 children first, at the time it was procured by the administration of then President Benigno Aquino III… The vaccine was not yet ready for distribution. Now we have the evidence on that,” he said in a statement.
Senator Nancy Binay called on DOH and Sanofi Pasteur to launch a nationwide medical advisory and information drive to reach out to parents whose children have had the vaccine.
“It is sad that the DOH ignored the warning about the issue of patient safety and research integrity of Dengvaxia. Safety should always be the paramount concern when it comes to any immunization program,” she said in a statement.
Garin launched Asia’s first public dengue vaccine program in April 2016.
Health authorities earlier warned the vaccine would have side effects, including fever, headache, muscle pain, weakness, redness, and swelling.
The program was halted in mid-2016 by former Health Secretary Paulyn Ubial pending results of the pilot program, saying the vaccine was not proven safe.
Three children allegedly died in 2016 after the administration of the vaccine, but health officials and pharmaceutical officials denied the claim.