By Charina Clarisse Echaluce
The government’s dengue immunization program has been suspended by the Department of Health (DOH) after reports that Dengvaxia, a dengue vaccine, can potentially cause a severe case of dengue.
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…. 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.”
In a press conference, Health Secretary Francisco Duque said the DOH will place the dengue vaccination program on hold while a review and consultation is ongoing with experts, key stakeholders, and the World Health Organization (WHO).
Duque said Dengvaxia was the first dengue vaccine to be licensed after being approved in Mexico in December 2015.
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.
Duque said there will be “mandatory history taking on the immunization of vaccinees” and “mandatory reporting of hospital cases of vaccinees regardless of the symptoms” to evaluate the program and ensure its safety.
Dengue fever and dengue hemorrhagic fever, which are transmitted by a bite of an Aedes aegypti mosquito, are acute viral infections that affect infants, young children, and adults. An average of 200,000 cases of dengue is reported every year, according to the DOH.
Sanofi Pasteur disclosed that a new analysis of long-term clinical trial data showed differences in Dengvaxia’s performance based on prior dengue infection.
For those who have not been infected by dengue, there is a possibility for them to get severe dengue.
The DOH, on the other hand, said the pharmaceutical company must clarify their definition of “severe dengue.”
Duque said Sanofi is using a classification—that identifies a case of dengue as “severe”– based on previous guidelines in 1996.
Health spokesperson Lyndon Lee Suy said “It’s totally different from the current guidelines of the WHO. Before, spontaneous nosebleeding classifies dengue as severe. But now, what is deemed severe is when there is an organ failure, water in the lungs or stomach.
“But then reviewing the guidelines, the ones classified by Sanofi [as severe] right now…most of the cases would not even fall under our current definition of severe,” Suy explained.
Those who had dengue infection prior to immunization will truly benefit from the vaccine, the health authorities stressed.
“For those who were infected prior to receiving the vaccine, there is a 93 percent reduction in the severity of the disease and 82 percent on hospitalizations,” Philippine Children’s Medical Center Chief Julius Lecciones noted.
Duque further explained, “For those who were not previously infected by the dengue virus, the analysis found that vaccination led to a benefit in preventing severe illness for at least 30 months. In the longer term, severe cases may occur following a subsequent dengue infection among those who were not previously infected.”
Lecciones noted that Brazil, another country that had a mass dengue vaccination campaign, will continue its public immunization program.
“They immunized almost the same number as the ones vaccinated here. There was no reported severe case due to dengue vaccination in Brazil,” he said.