Dengue vaccine, Dengvaxia, can still benefit Filipinos, manufacturer Sanofi Pasteur stressed during a press briefing held Monday, December 4, in Taguig City. Officials of the global pharmaceutical company added that the dengue vaccine could give up to six years of protection against the mosquito-borne illness to those who have had dengue.
Questions were raised after Sanofi Pasteur released a statement last week that while Dengvaxia proved effective in those who have had a previous dengue infection, it increased the risk for "severe dengue" for those who have not been infected with the virus.
“The analysis confirmed that Dengvaxia provides persistent protective benefit against dengue fever in those who had a prior infection,” the global biopharmaceutical company says in a press release dated Novemeber 29. “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.” (Read more here.)
At the press briefing, Sanofi Pasteur clarified that “severe” does not immediately point to life-threating conditions such as dengue shock, a complication of dengue infection associated with high mortality.
“Ang severe could only be ‘yong lagnat ng dalawang araw, at kapag may suspect na case ng dengue, ‘yong platelet count p’wede bumaba,” said Sanofi Pasteur regional director Dr. Joselito Sta. Ana. “P’wede ring kapagka nabunggo ka, magkaka-hematoma ka o magkakapasa ka. At p’wede ring parang pagka nainitan ka, mababalinguyngoy ka.”
For every 1,000 individuals who were given the vaccine and had no history of dengue, two were reported to have experienced severe dengue, according to a follow-up study conducted by Sanofi five years after its initial tests.
“All study participants who got severe dengue, whether vaccinated or not, have fully recovered,” said Sanofi, adding that the severe dengue observed in vaccinated individuals was not clinically different from unvaccinated individuals in the studies.
According to Sanofi Pasteur, findings showed a decrease of 15 hospitalization cases and four fewer dengue cases per 1,000 individuals among those who have a history of dengue and were given the vaccine.
Based on epidemiology data existing in the Philippines, “nine out of 10 individuals, by the time they reach adolescence, have already been infected by dengue,” said Dr. Ng Su Peing, the global medical head of Sanofi. According to Dr. Peing, the majority of these individuals (75 %) are asymptomatic or will show no signs of symptoms of the illness; patients may have had dengue without knowing it.
Based on the above, it will be difficult, Sanofi Pasteur says, to tell if a child has had dengue before getting vaccinated (unless a child was diagnosed by a doctor, of course). “Unfortunately, there are no dengue diagnostic tests today that you could use in someone who’s been vaccinated to tell if they have had a previous infection before vaccination,” said Dr. Peing. Because the immune system has already been stimulated by the vaccine, tests will come out positive in both individuals with and without a prior history, she explained.
That said, the Department of Health has put on hold the Philippines’ dengue immunization program until a proper evaluation is conducted. (As of November 2017, more than 733,000 Filipino children have received Dengvaxia.) The agency has also come up with a framework for the actions it will take in the light of Sanofi Pasteur's findings. It includes profiling all students who received the vaccine, mandatory reporting of all hospitalization cases, and a 5-year surveillance post-vaccination. They will also review the current dengue immunization guidelines.
If your child has been given a shot of Dengvaxia but has not completed all three doses, Sanofi Pasteur advised parents to consult with their child’s doctor for the next best step to take.
Vaccinated or not, it’s important for all parents to monitor their children for symptoms of dengue, added Dr. Peing.
Meanwhile, Interakyson reported, “Department of Justice Secretary Vitaliano Aguirre II ordered the National Bureau of Investigation to look into the ‘alleged danger to public health arising from the P3.5 billion anti-dengue vaccination drive’ of the DOH.” Appropriate charges may be filed against those proven liable.
Sen. Risa Hontiveros is also urging the government to take concrete steps to address the issue such as a database to “keep track of the [children’s] health and prepare the needed resources and logistics that will allow for quick and appropriate medical responses.”
“Sanofi must be held responsible and the culpable health officials accountable,” she said. The DOH “owes the public an explanation on how the controversial vaccine was acquired in the first place and why it failed to heed the apprehension and warnings of medical experts on its potential dangers,” she added. Sen. Hontiveros is the chairperson of the Senate Committee on Women and Children and vice-chair of the Senate Committee on Health and Demography.
Sanofi says it will work with the DOH.
UPDATE: The Food and Drug Administration (FDA), on Dec. 4, ordered Sanofi to pull out Dengvaxia from the market and suspend its sale, distribution and marketing “pending compliance with the directives of the FDA.” The agency also directed the pharmaceutical company to conduct an information dissemination campaign with advisories, Dear Doctor letters, and forums with patients.
As a statement in response to the FDA, Sanofi said it will work with the FDA “to review the implementation of their direction” and “will continue to seek constructive and transparent dialogue with them.”