1,107 deaths in Philippines from dengue epidemic: 113% higher than 2018

Manila: The spike in dengue deaths topped 100 per cent in the Philippines in the first eight months of 2019.

Latest official data show that between 1 January and 31 August 2019, 271,480 dengue cases — including 1,107 deaths — were reported through the Philippines' Department of Health routine surveillance system.

The death toll is a 113 per cent spike compared to 655 dengue deaths reported during the same period in 2018.

Here's the link to the World Health Organization report covering the January 1 to August 31, 2019 period.

With a median age of 12 years, the most affected age group among dengue cases is 5-9 years (23%).

Similarly, the most affected age group among dengue deaths is 5-9 years (39%).

The majority of dengue cases are male (52%), whereas the majority of dengue deaths are female (53%).

Between 25 and 31 August, 12,526 cases and 41 deaths were reported.

In the preceding week, 13,192 dengue cases were reported, with 38 deaths. Still, this was 52% higher than in 2018.

Similarly, the weekly case fatality rate (CFR) of 0.33% in epidemiological week 35 is lower than in the same time period in 2018 (0.40%).

Mosquito-borne virus

Global incidence of the mosquito-borne virus — which causes flu-like symptoms and can lead to potentially fatal complications in a small percentage of cases — has increased in recent decades, with significant rises throughout Southeast Asia, the Western Pacific, and Latin America.

The advance has been attributed to several factors, including increased urbanisation, travel, and population growth, as well as climate instability, with increased rainfall in endemic regions enabling greater mosquito transmission.

A national vaccination campaign was launched in the Philippines in 2016, but the government decided in 2017 to ban the sale and distribution of Dengvaxia, after Sanofi Pasteur, the vaccine’s manufacturer, released new data indicating an increased risk of severe dengue in vaccinated individuals who had not previously been exposed to the virus.

Dengvaxia, the world’s only internationally-licensed dengue vaccine, has since become a controversial political tool in the Philippines.

In November 2017, the Duterte government temporarily suspended the government-funded Dengvaxia innoculation program.

That was after the head of Public Attorney's Office has declared Dengvaxia as the culprit behind the death of 143 children and 3 adults who were given Dengvaxia shots during a program started by the previous administration.

Forensics

Dr Erwin Erfe, a forensics expert work­ing for the Philippine Public Attorney’s Office, has led a team that performed autopsies on 132 bodies they suspected of Dengvaxia-related deaths. 

A group of experts from the University of the Philippines-PGH training hospital said, debunked the claims of Dr Erfe saying it was "unscientific", while others questioned his credentials in medical forensics.

Between April 2016 and November 2017, Dengvaxia was admini­ster­ed to more than 800,000 children in several pilot regions in the country.

About 600 children who died after they received Dengvaxia are under investigation by the Public Attorney’s Office.

No tests were performed on individual Philippine children to see whether they had been exposed to the virus before vacci­nation.

According to one report, between 80,000 and 120,000 of the Dengvaxia recipients are now more at risk of death if they contract dengue than they were before they had been vaccinated.

In February 2019, authorities in the Philippines announced that Dengvaxia had been permanently banned in the country.

Dengue is spreading rapidly around the world, infecting 390 million people every year – 100 million of whom develop symptoms, with 500,000 of those contracting haemorr­hagic fever.

Did WHO fail in giving green light to Dengvaxia?

Dengue fever was identified as early as the 18th century. Attempts to produce a vaccine had failed.

Professor Scott Halstead, 88, who is one of the world’s foremost experts on dengue fever, says there was a global sense of relief when Sanofi at last found a vaccine that appeared to work reasonably well.

In March 2016, the WHO published a detailed assessment of Dengvaxia, stating that “there is a theoretical possibility that vaccination may be ineffective or may even increase the risk in those who are sero­negative at the time of first vaccination”.

Nevertheless, the WHO gave a green light for its use in the most affected areas of the world.

The increased risk to seronegatives is due to a singular mechanism of dengue, known to scientists for several decades: antibody-dependant enhance­ment (ADE).

Once a person is infected by one of the four strains of the disease, they are immune to that particular strain for the rest of their life. But, in the case of a second infection, by another strain, the antibodies developed to fight off the first infection might become “double agents”, helping the new infection to pass through the barriers of the immune system.

Not a theory

Sanofi calls this “a theory”.

However, Professor Halstead countered: “The phenomenon is now quite well documented, you cannot call it a theory anymore.”

By mimicking a first infection, the Dengvaxia vaccine makes some "seronegative" (giving a negative result in a test of blood serum, e.g. for the presence of a virus) children more vulnerable in the event of an attack — instead of protecting them.

In Sanofi’s clinical trials, ADE was seen to be a higher risk for younger children.

Those under the age of five were almost eight times more likely to contract a severe form of dengue after receiving the shot — compared to the children in the control group, who didn’t receive the shot.

Sanofi, however, explained this as being an “immature immune response” and set the minimum age at which children should receive the vaccine at nine years old.

“This is not biologically sensible,” Halstead countered. “When they are nine years old, children have statistically more chances to have been previously infected than the very young ones. But the risk remains for all seronegative children, regardless of their age.”

Clinical trials

Halstead tried to warn Sanofi and the Philippine author­ities of his concerns, but to no avail. He sent a video explain­ing the potential risks of the vaccine to a local contact, hoping it would be broadcast in the Philippine Senate, which it was, finally, but only during a hearing held to identify where responsibility for the Dengvaxia mess lay.

On August 8, President Rodrigo Duterte, said he is open to the use of Dengvaxia again in the country following the health department's recent declaration of a national dengue epidemic.

"Yes, I am open to the use of Dengvaxia again. Maraming patay (Many have died), it's an epidemic," Duterte said.

"Now, compare it vis-à-vis to those who died, I want to hear the words of the experts, doctors, and we have enough bright people to tell us. I don't need foreigners to tell me, my own Filipino scientists and doctors would tell me what to do. I will be guided by their announcements," Duterte added.