MANILA - Five years of "heightened" monitoring of children vaccinated with Dengvaxia may not be enough, according to a medical specialist.
During a Senate probe on Thursday, Dr. Mary Ann Lansang said a related incident in Cuba required medical specialists to check on patients for up to 20 years.
"Five years of surveillance may not be enough for these children. If you look at the experience of Cuba, they have a 1977 epidemic. The antibody-dependent enhancement phenomenon was seen 4 years after (1981) and 20 years after (1997)," she said.
Lansang was referring to a case in a Cuban municipality in 1997, where dengue reemerged two decades after the country had its first dengue epidemic in modern times.
The reemergence of the dengue occurred even as Cuban authorities were implementing a passive surveillance system on suspected dengue patients, said the Centers for Disease Control and Prevention.
It was found that patients in 1997 were infected by a dengue strain different from what was prevalent in 1977 or 20 years ago. An "antibody-dependent enhancement" (ADE) of the dengue virus was also observed.
ADE happens because antibodies developed by the immune system to fight a virus are unable to fight the same virus of a different strain, making the viral infection more acute.
Given this learning, Dr. Lansang believes that it will be more prudent for the Department of Health to monitor the over 800,000 affected children for a longer time period.
The suspended dengue vaccine program which started under the Aquino administration has caused a public health scare after French drug-maker Sanofi said its product Dengvaxia may cause more severe symptoms on those who get the disease but have not been previously infected.
Health Secretary Francisco Duque III earlier said the department is gearing up for a 5-year "heightened surveillance" of the children vaccinated with Dengvaxia.
Duque said they are putting up a master list of all the affected children, as well as a "dengue hotline" for their families as they monitor them for 5 years post-vaccination.