Health advocates express long-term safety concerns
By MYLENE C. ORILLO
THE recently rolled out nationwide dengue vaccination of the Department of Health (DOH) targeting around one million school children aged nine years and older drew concerns from several known health advocates.
Dr. Willie Ong said in a media interview that although the vaccine appears promising and backed up by some studies done in countries wherein dengue fever is prevalent, including the Philippines, it is usually not a good idea to be the first to use any drug which has not been extensively administered yet to the public in a real-world setting.
Dr. Ong also does not advise that the Philippines should be the last to try it, but being somewhere in the middle would be ideal since more clinical experience on the vaccine is already available, particularly its long-term effects.
As in many new drugs, adverse effects may not be seen in the acute administration or during the first few months or years, but long-term side-effects may be seen only on the long-term.
Meanwhile, in a separate press conference, Dr. Antonio Miguel Dans, academician and professor at the University of the Philippines College of Medicine, revealed that from the very start, vaccine manufacturer Sanofi Pasteur already noted and was concerned about a potential problem with dengue vaccines; i.e., while the vaccine could lower the number of cases of dengue initially, it might later increase the severity of disease for those who received it, although it’s not yet proven.
This phenomenon is called “antibody dependent enhancement (ADE)”, which is being monitored closely by the pharmaceutical company.
“This is their biggest fear. So what they did when they did the study, they make sure they will follow up not just for two years, three, four, five, and six-year follow-up because ADE is a late phenomenon – it’s a fourth quarter rally,” revealed Dr. Dans.
Dr. Dans explained that it takes time to study ADE. Citing the company’s own studies, he explained that this may start to happen by the 3rd year after vaccination.
While the Sanofi and the DOH claimed ADE was only seen in children lower than nine years old, the data showed that it could be happening in both younger and older children, and in adults as well.
“The real dengue we are afraid of is severe dengue, not the mild ones,” said Dr. Dans. “If a vaccine prevents mild disease but causes severe dengue, we shouldn’t be using it at all.”
Dr. Dans pointed out that Sanofi and DOH are aware of the possibility they there may be a rise in cases of severe dengue two years after this program is implemented.
Proofs of doubts include DOH’s planning intensified surveillance and securing parental consent for vaccination, which are not usually done for vaccines proven safe.
He claimed the greatest proof that DOH and Sanofi are aware of the possibility of ADE is the fact that their clinical trial is going on. “If they are sure that ADE is no longer possible, they should stop the trial,” Dr. Dans added.
In the same press conference, Dr. Anthony C. Leachon, president of the Philippine College of Physicians Foundation, also clarified that they are not against dengue vaccine, but would also advise against the haste in administering it to the public.
“Don’t get me wrong. We are excited right now that there’s a vaccine for dengue. We want this vaccine to succeed, but let’s wait for the WHO (World Health Organization) guidelines. Haste makes waste. No matter how important this drug is, our mantra as doctors is to first do no harm,” he said.
The Strategic Advisory Group of Experts (SAGE) report is yet to be released by the WHO on the said vaccine.
WHO gives guidelines on how to administer vaccines – its efficacy, quality, and safety. It gives an independent opinion without bias to any company.
The vaccine was approved in 2015, barely five months after the DOH decided to launch and implement it nationwide.
“As health advocates, we appeal to the DOH to wait until the study is completed and put in place safeguards to protect children from possible adverse effects on their health,” said Dr. Leachon, who also served previously as a medical director of a large multinational pharmaceutical company, which has launched several breakthrough products.
According to Dr. Leachon, there should be a year of post marketing surveillance study to know the drug’s efficacy and safety.
“We are the first country in the world (to use the vaccine)! For so many years, the Philippines usually wait for the US or Europe to initiate because they have rigid monitoring. The risk of losing is greater than the benefits if we rush this. It’s only a matter of months,” he said.
Since WHO has yet to issue an approval over the public health use of Dengvaxia® (CYD-TDV), the DOH can wait for a year until the completion of the study on patients, or wait for the prequalification of the vaccine in the WHO in two years.
The WHO Prequalification of Medicines Program ensures that millions of patients in resource-limited countries like the Philippines receive life-saving medicines that are purchased by or through international procurement agencies such as UNICEF, UNFPA, UNITAID and the Global Fund to Fight AIDS, tuberculosis, and malaria.
Aside from ensuring the vaccine’s quality, safety and efficacy, Dr. Leachon explained that prequalification would lower its cost and will save more children from the disease.
“Vaccination program for common diseases, such as, tuberculosis, diphtheria, pertussis, measles, polio, hemophilus influenza B, and hepatitis B with a performance rate of 60 percent as compared to the PhP 3.5 billion for dengue only. While the expanded immunization conducted since 1976 has not been perfected yet,” said Dr. Leachon.
In 2015, a national survey by the Food and Nutrition Research Institute showed that only 60 of children received all these essential vaccines.
Warning to all parents
“We are talking about the lives of our children here and their future,” said May-i Fabros of WomanHealth Philippines, whose group is also a member of the Alternative Budget Initiative for the Health Cluster which monitors the budget spending for health, including the PhP 3 billion for dengue vaccination.
According to Fabros, parents were not fully aware of the risk of ADE, which is not even mentioned in the consent forms. Parents were not advised that their children can have fever, weakness, allergic reactions, or 60-percent chance of having adverse dengue effect, and lastly where to go in case of emergency.
Fabros is also worried that if the DOH insists on proceeding with the vaccination and adverse events on the children’s health condition are encountered, the people will lose confidence on the government’s entire vaccination program.
“We’re risking the integrity of the entire public health institution, and even worse, we are putting 1 million nine-year-old kids at a cost of PhP 3 billion in a potential danger with 60-percent chance of having severe strain of dengue. I don’t know what’s even more expensive, what’s even more important to us,” she said.
Vital Signs Issue 86 Vol. 4, April 1-30 2016