The Department of Health has ordered that all dengue vaccination activities in the public sector be put “on hold,” amid an advisory from manufacturer Sanofi Pasteur warning against their own dengue vaccine’s differences in performance.

Pharmaceutical giant, Sanofi Pasteur, through continuous clinical trials, found the vaccine (Dengvaxia) performed differently based on prior dengue infection.

The clinical data analysis, which spanned six years, confirmed that the dengue vaccine does provide “persistent, protective benefit against dengue fever” for those who had prior dengue infection.

However, for those who have never been infected by dengue virus, “the analysis found that in the longer term, more cases of severe disease could occur following vaccination upon a subsequent dengue infection,” the Sanofi advisory said.

Local public operations “on hold”

Health officials in the Philippines, one of the countries which approved of the vaccine for use, quickly convened following the Sanofi advisory.

“The Department of Health (DOH) will place the dengue vaccination programme on hold while review and consultation is ongoing with experts, key stakeholders, and the World Health Organization (WHO),” announced Secretary of Health Francisco Duque III during a press conference held on December 1 at DOH Central Office.

Sanofi gave the Health department preliminary briefing regarding the vaccine prior to the press briefing.

The DOH noted that based on the report, the vaccine has shown consistent and sustained benefit specifically for those previously infected with the dengue virus.

"The analysis found that vaccination led to a benefit in preventing severe illness for at least 30 months. However, in the longer term, severe cases may occur following a subsequent dengue infection among those who were not previously infected," the Health department said, which led to the decision to suspend programme started in early 2016.

Since the first phase of the mass vaccination drive, no severe dengue case has been recorded.

Health Secretary Duque mentioned the department and its legal team are reviewing the contracts and the documents pertaining to the programme while “on hold.”

Post-vaccination surveillance

It is not yet known how many of the children who received the vaccine had prior infection. Secretary Duque said they are working on completing the data.

But about 700,000 individuals have received at least one dose of dengue vaccine in three areas where dengue is highly endemic - Regions III, IV-A and the National Capital Region. This is in line with the WHO recommendation to mass vaccinate in endemic areas.

Two hundred thousand cases of dengue are reported yearly in the country on average.

The dengue vaccine was first administered among Grade 4 students, aged 9 in April 2016. The vaccine is given at three doses and six months apart in between doses.

Asked about the plans for children who had no prior dengue infection but received the vaccine, Secretary Duque said there is framework the department will follow.

“There will be mandatory history taking, mandatory reporting of vaccinees’ hospitalization, mandatory investigation and a five-year surveillance post vaccination,” said Secretary Duque.

In addition, DOH Assistant Secretary Lyndon Lee Suy already alerted regional branches regarding the changes, and these regions will coordinate with health providers in turn.

Decision up to private practitioners

The Health chief stressed the order to put the vaccination programme “on hold” only applied to all public health facilities, while it will be up to private practitioners to follow government’s decision or not.

“This is just from the government’s point of view regarding their programme. The private physicians have a different will be up to the health care provider if he or she would like to put on hold [or] implement the programme as well in his or her practice,” said Dr Benjamin Co, Director of Center for Drugs of the Food and Drug Administration (FDA).

Sanofi Pasteur, in its media release, proposed a change in label.

“Sanofi will propose that national regulatory agencies update the prescribing information, known as the label in many countries, requesting that healthcare professionals assess the likelihood of prior dengue infection in an individual before vaccinating,” it said in the statement.

It further added that vaccination should only be recommended when the potential benefits outweigh the potential risks.

“For individuals who have not been previously infected by the dengue virus, vaccination should not be recommended,” the statement read.

Vaccinations still helpful

Meanwhile, Secretary Duque assured the public that the agency was serious in carrying out its mandate to "always guard the health and well-being of its constituents." To this end, it will ensure that vaccines given to the public are always safe and effective to optimize its health benefits.

The DOH is asking parents of children who received the vaccine but had no prior infection to remain calm.

“The protective benefit of the vaccine - especially for those children who had prior infection - is still high in terms of much reduced hospitalization, much reduced severity of illness,” said the secretary.

At the same he underscored that even to beneficiaries with no prior exposure to dengue but received the vaccine, its protective benefits is for 30 months.

As to the impact of the findings on immunization as a whole, Secretary Duque hopes that the value gained in the local Expanded Program on Immunization (EPI) will not be lost.

“I hope that this development will not, in any way, affect the DOH EPI because there are countless number of lives that have been saved and so the value of that has to be preserved. Our vaccination programme should be enhanced and strengthened and we are committed to do exactly that, as reflected by the massive investment DOH is preparing for this programme,” Secretary Duque said. MIMS 

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