By: Jennifer P. Rendon
AS DENGUE cases in the Philippines surge, particularly in Western Visayas, there have been calls to resurrect the use of the controversial Dengvaxia vaccine.
One of the most vocal advocates of Dengvaxia is Rep. Janette Garin of the first district of Iloilo.
Garin was health secretary when Dengvaxia was registered and used in mass school-based dengue immunization programs.
As she appealed for Dengvaxia’s return to the market, Garin pointed out that only those with dengue or were infected before should be vaccinated while persons who have yet to be infected will not be vaccinated
She also proposed that if the vaccine will not be available to government doctors, it should be made available to private practitioners.
But Garin’s recommendation did not appeal to current Department of Health Secretary Francisco Duque III.
“We need to study the recommendation. Why? The available tests are not very specific. In other words, there’s no specificity. The question remains whether it is really the dengue virus that has been picked up by the test?” Duque said.
It should be remembered that the current tests for dengue cross reacts with other flaviviruses, he pointed out.
As such, the test result would yield positive yet it could be chikungunya, or Japanese encephalitis, or even zika virus.
“If it’s positive, you’re not sure whether he’s positive for dengue virus because as I’ve said, it cross reacts with other viruses. Eh papano pala ‘pag hindi dengue at Zika pala siya then binigyan mo ng Dengvaxia,” Duque said.
If that’s the case, Duque said the individual will be seronegative, which mean he or she should have actually enjoyed the benefits of Dengvaxia if the person had prior exposure to the wild dengue virus.
And that’s where the problem arises.
“So, give us a test that has a very high, not only sensitivity but has also specificity. Kung talagang it’s tested dengue, then my confidence level goes up. Then I can recommend Dengvaxia,” he said.
He added that for seropositive individuals or children, it does provide a certain level of protection which in fact is about 60-65 percent.
“But still, even that is not a high protection rate,” he said.
Duque said that the risk has to be balanced with many other factors.
“The problem is we don’t have a test to say specifically that it’s really just dengue. What if it’s Zika or chikungunya, eh di balik tayo sa dating problema natin,” he said.
He pointed out that even Sanofi Pasteur, the maker of Dengvaxia, acknowledged the increased risk of severe dengue posed by Dengvaxia on individuals who had received shots.
“In this supplementary analysis, we found an increased incidence of severe disease in vaccinated people without a prior infection compared to unvaccinated people without a prior infection,” Sanofi Pasteur said in a statement.
Duque is hopeful, though, that a new vaccine being tested by Takeda, a Japanese global pharmaceutical company, against four strains of the dengue virus would be the answer to the dengue outbreak.
“Hopefully, dengue vaccine by Takeda is proven effective but they are not yet done with their clinical studies so we are waiting that one day there is going to be a vaccine that is going to be effective for all the four strains of dengue,” he added.
It can be noted that the Food and Drug Administration has suspended the sales, marketing and distribution of Dengvaxia after the company acknowledged that the vaccine poses a higher risk for severe dengue and hospitalization in people with no prior exposure to the virus.
The FDA announced it has permanently revoked the certificates of product registration (CPR) of the vaccine because of “Sanofi Pasteur Inc.’s continued failure to submit postapproval commitment documents.”
Intensified dengue response
Duque was in Iloilo City on July 25, 2019 for a dialogue with local officials in Panay and Guimaras islands.
He also inspected hospitals and other health facilities to assess the situation and extend needed assistance from the DOH.
As of the 28th morbidity week (Jan. 1 – July 31, 2019), a total of 18,834 dengue cases have been recorded by DOH-Center for Health Development in Western Visayas (DOH-CHD 6), a 359 percent increase compared to the same period last year (5,251 in 2018).
The province of Aklan has the highest attack rate of 406 (2,460 cases versus 678 in 2018) while Guimaras has the highest percent increase at 1,258 percent (384 cases vs 52 in 2018).
The DOH also recorded 94 deaths in the region, with the province of Negros Occidental posting the highest number at 24. This corresponds to a regional case fatality rate of 0.5 percent, which is lower than the 0.8 percent CFR in the same period last year.
Also, the age range of dengue patients is from 27 days old to 98 years old, with the median age at 12 years old.
The most number of cases are in the 1 to 10-year old age group.
To date, the provinces of Akon, Antique, Capiz, Guimaras, and Iloilo; and Iloilo City have already declared dengue outbreaks.
Iloilo and Antique provinces have also declared a state of calamity because of the rising number of dengue cases.
The municipalities Culasi and Sebaste in Antique and Maasin, Iloilo have declared a state of calamity in their respective localities.