Reconsidering the ‘permanent ban’ on dengue vaccine

Most hospitals in Metro Manila are fully occupied these days, and I think it’s because of suspected dengue cases.

In July, the Department of Health (DOH) issued a national alert status for dengue. In August, several regions breached the threshold, and a national epidemic was declared. A 98-percent increase in dengue cases was reported from January to July this year, with close to 150,000 cases filling up the hospitals and a rising death toll.

Meanwhile, Filipinos who can afford it are bringing their children to Singapore for vaccination. Former Health Secretary Dr. Espie Cabral shared on our Viber group some information on how one can access the dengue vaccine.

One may go to the Singapore General Hospital and get tested for previous dengue infection, since in endemic areas like the Philippines, it’s possible to have been previously infected with dengue without knowing it. If the test turn out negative, vaccination is not advised. If positive for past infection, one proceeds to consult a physician there and get the prescription for vaccination.

The problem is that private clinics do not always have the vaccine in store, and the doctor orders only as needed. So one may have to wait until the vaccine is available.

You can imagine how costly getting a dengue vaccination now is for Filipinos. The price of the test is from S$60 (P2,330) to S$80 (P3,110), excluding doctor’s consultation fee which varies.

Adding the plane fare and accommodations for a few days until one gets the vaccine, expenses can reach more than P50,000 to get a dengue vaccine in Singapore.

That may be reasonable for some, but not for the millions of Filipinos who can barely make both ends meet.

Since the vaccine requires three doses, one has to go back to Singapore for the second and third doses. Dr. Cabral does not advise buying the second and third doses and bringing them back to the Philippines, since faulty storage can make the vaccine ineffective.

Sad irony

This is the sad irony of the dengue vaccine story. We were among the first countries in the world to have the vaccine available and use it massively, and now we have to spend a hefty sum just to have our children vaccinated because it is no longer available here.

I think the DOH and the Food and Drug Administration (FDA) should reconsider the registration of the vaccine, but under strict instructions of usage.

We were among the first to express apprehension on the potential long-term adverse side effects of the Sanofi-manufactured dengue vaccine, Dengvaxia, in our previous columns (“A second thought on the dengue vaccine,” 04/15/16; “Rejoinder on the dengue vaccine,” 04/22/16; “Dengue vaccine: The recent history,” 12/05/17; “Should the government spend P3B on a potentially harmful vaccine?” 11/08/16).

Our worry was then were mainly due to “knowledge gap” on the vaccine’s long-term safety, particularly three years after its use.

The clinical trial findings, published in the New England Journal of Medicine (NEJM), could not assure that there would be no serious long-term side effects in all children who were vaccinated. Even the authors of the NEJM study acknowledged that they did not have the answers to several questions, and it is hoped that continued monitoring of cases and other ongoing studies would provide the answers later on.

Guidelines

We recommended clear guidelines on the types of individuals who would benefit most from the vaccine. In short, the benefit should far outweigh the risk.

But at the time, we seemed overwhelmed by our glee over potential benefits, and there were some red flags that we unwittingly dismissed.

It only became clearer later that if Dengvaxia was given to individuals who hadn’t been exposed to dengue, there was a risk of more serious infections when they got infected with the virus naturally. However, when given to individuals aged 9 or older who already had a previous infection, the vaccine has a protective effect.

One thing unique with dengue, compared to most infectious diseases, is that the second infection is typically much more serious than the first. Researchers have already established that when the vaccine is given to dengue-naive individuals (someone without previous dengue infection), it acts just like a natural infection “but without making recipients sick.”

Should the vaccinated individual get infected by dengue naturally, his or her immune system then treats it as a second infection that can be much more severe.

So, each child given the vaccine should be tested first. We emphasized in our previous columns before and during the mass vaccination program that, presuming that the child has been exposed to dengue, since it’s endemic in the country, was not a sound practice of medicine. It’s what the local adage warns: “Marami ang napapahamak sa maling akala (Many get in trouble because of wrong assumptions).”

Mass vaccination was definitely not a good idea. I think dengue vaccination, just like most forms of vaccination, is good and potentially life-saving. But when not administered properly, that’s where the problem develops.

I did not agree when the FDA cancelled the registration of Dengvaxia and permanently banned it in the country. It’s like throwing the baby out with the bath water. It was a knee-jerk reaction, trying to correct a mistake with another. It should have just reinforced stricter guidelines on its usage.

DOH and FDA officials should probably humble themselves and admit that recent developments and scientific evidence dictate it’s time to reconsider the decision, and once again restore the confidence of the people in immunization and other preventive measures to prevent potentially life-threatening diseases.

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