MANILA, Philippines — The Philippines has not yet lost its polio-free status despite having two cases of the highly contagious disease, the World Health Organization stressed Wednesday.

Rabindra Abeyasinghe, acting WHO representative in the Philippines, explained that a country remains polio-free if no new case of wild poliovirus has been reported.

“The Philippines continues to remain polio free... The occurrence of the vaccine derived polio cases does not constitute the fact that you have lost your polio-free status,” Abeyansinghe said in a press briefing.

The last case of wild poliovirus is the Philippines was reported in 1993. WHO declared the country-polio free in 2000.

Only Afghanistan and Pakistan are the only two countries where the wild poliovirus has not been eradicated.

“Vaccine derived polio is not unique,” Abeyansinghe said, citing outbreaks in Papua New Guinea, China and Laos.

In the Philippines, there are reported two cases of polio—a three-year-old-girl from Lanao del Sur and a five-year-old boy from Laguna. Both cases were caused by the vaccine-derived poliovirus type 2.

In 2015, WHO certified that type 2 virus has been eliminated around the world so this strain was removed in the oral polio vaccine.

“All oral polio vaccines produced and distributed since 2016 only give protection to type 1 and 3 and for the children in the Philippines, children will only be protected from type 2 if they get the immunized polio vaccine, which is a mixture of all three,” Abeyansinghe said.

Low vaccine coverage

The acting WHO representatives in the Philippines stressed that the transmission of vaccine-derived polio usually happens when the vaccine coverage in an area is inadequate.

“It’s unfortunate that in the Philippines, the vaccine coverage is far from satisfactory,” Abeyansinghe said.

The oral polio vaccine coverage in the Philippines for three doses is only around 66%—way below the target of 95%. The coverage of the injectable vaccine is even lower at only about 40%.

“That means that one in three children is not receiving their vaccine. This situation is giving rise to the occurrence of vaccine derived polio outbreaks,” Abeyansinghe said.

He also pointed out that while the Dengvaxia controversy has contributed to the low vaccine coverage, it is not the only factor that gave rise to the low immunization rates in the country.

“Vaccine coverage for polio was around 70% even before the Dengvaxia issue happened. The Philippines has been at high risk for the emergence of such situation. It’s critically important that we ensure that all children have access to vaccines on a regular basis,” Abeyansinghe said.

Polio is a highly infectious viral disease, which mainly affects young children. The virus is transmitted by person-to-person spread mainly through the fecal-oral route.

Initial symptoms of the disease include fever, fatigue, headache, vomiting, stiffness in the neck and pain in the limbs. Polio can cause paralysis, which is often permanent, in a small proportion of cases. — Gaea Katreena Cabico