Kids injected with Dengvaxia more likely to get severe dengue after two years — expert

Children who receive the dengue vaccine Dengvaxia are more likely to get severe dengue after immunization, if data from manufacturer Sanofi Pasteur is to be believed.

"Yung nakita namin is seven times increased risk nila kung nabakunahan sila compared sa mga hindi nabakunahan, kung they never had dengue before," pediatrician and UP professor Leonila Dans said on "Bawal Ang Pasaway kay Mareng Winnie" on Monday.

"Nag-increase nga kaya I think iyon ang naging rason kung bakit ang desisyon ng Sanofi eh talagang hindi na ito recommended sa seronegatives."

She said the basis for this conclusion were the results of the year-3, follow-up on Sanofi's Asian clinical studies in 2011.

Sanofi's clinical studies on Dengvaxia began in 2011 and concluded on November 2017.

"Kaya lumabas na ngayon yung reports nila saying na harmful na sila kasi ngayon lang talaga natapos yung full study ng Sanofi," Dans said.

Dans clarified in a phone interview with GMA News Online that the "seven times" she mentioned on "Bawal ang Pasaway" pertained to patients aged two to five, who were more likely to be seronegative.

5 times more likely to have severe dengue

"Yung seven na yun actually came, if you look at the original study, yung children na two to five-years-old, dun nakakuha ang seven times more likely to have severe dengue," she explained.

"Ina-assume kasi natin na pag two to five-years-old sila yung seronegative, kaya nasabi kong seven," Dans continued.

"Among two to five-years-old who are more likely to be seronegative, ang nakitang finding is they are seven times more likely to have severe dengue in the vaccinated group."

All patients, regardless of whether they previously had dengue (seropositive) or not (seronegative), injected with Dengvaxia were 5.5 times more likely to contract severe dengue compared to the control group.

The patients, aged 2 to 14, and were located in the Philippines and other Asian countries.

"Ito magkasama yung seropositive at seronegative, yung has had or did not have dengue before the vaccination. Basta if you're vaccinated, you're five times more likely to have severe dengue compared to those who did not receive the vaccine," Dans explained.

Worse effects on previously uninfected patients

Dans said Dengvaxia has a worse effect on seronegatives than seropositives as the vaccine creates antibodies to defend the host against the dengue virus.

"Yung seropositive, yung nagkadengue na, parang yung bakuna binubooster lang sila, kasi para magka antibodies. Ayaw mo kasing bumagsak yung anti-bodies na 'yun eh. 'Pag bumabagsak na siya, dun ka nagkakasevere dengue," she explained.

"Eh bakit sa seronegative? Kasi hindi pa sila nagkakaroon ng antibody ever, wala silang anti-body sa katawan. Ang hina ng antibody production nila from the vaccine so ang bilis bumagsak. Pag-bumagsak sila, severe dengue na sila agad," Dans continued.

She added, "Parang artificial yung antibodies na ginawa sa kanila kasi they never had the dengue infection."

Former DOH undersecretary Dr. Teodoro Herbosa said in April 2016 that data from Sanofi indicated a risk of exposing the inoculated to a "more serious disease" once the vaccine effects wane two years after injection.

Dans, her husband and epidemiologist Dr. Antonio Dans, and other health advocates strongly recommended the suspension of the school-based dengue vaccination program in 2016.

Their opposition was based on an extensive study on Sanofi's data, other studies on the dengue vaccine, and a New England Journal of Medicine article titled "Efficacy and Long-Term Safety of a Dengue Vaccine in Regions of Endemic Disease."

Not all vaccinated will develop severe dengue

Dans said on "Bawal ang Pasaway" that it is important for parents to understand that not everyone vaccinated with Dengvaxia will develop severe dengue.

"Importanteng malaman din ng mga nanay na magtatanong na hindi lahat ng nabakunahan ng ganito, 'di nila alam kung nagkaroon na ng dengue o hindi, ay magkakaroon ng dengue," Dans said.

Nevertheless, she said parents must be vigilant in detecting the symptoms of dengue in their children so they must rush them to the nearest hospital or health care provider for treatment.

"Pero ang importante, alam nila na may posibilidad na magkaroon. Kung magkalagnat, magkaroon ng simptoma na nagsususpetsa sila na dengue, kailangan magpakonsulta agad," Dans said.

She reminded parents that their medical consultation and hospital fees can be subsidized by PhilHealth's case rate package for dengue worth P16,000.

Parents, schools, and communities, must also abide by the 4S program against dengue to prevent the number of dengue cases from rising.

4S stands for: search and destroy mosquito nesting places; use self protection measures such as mosquito repellents; seek early consultation; and say yes to fogging to hot spot areas where an increase in cases is registered for two consecutive weeks. — Rie Takumi/BAp, GMA News