MANILA - Forensic examination conducted on 4 children who received a controversial dengue vaccine indicated a "pattern" that led to their deaths, the Public Attorney's Office said Wednesday.

• Isa pang 'biktima' ng Dengvaxia, inawtopsiya ng PAO

• Forensic tests made on kids who allegedly died due to Dengvaxia

The Philippines late last year halted the vaccination of public school students with the vaccine Dengvaxia after French drug maker Sanofi disclosed that it might increase the risk of severe dengue in recipients not previously infected by the mosquito-borne virus.

• Philippines suspends dengue vaccine program after Sanofi warns of risks

Dr. Erwin Erfe, head of the PAO Forensic Laboratory, said the 4 children they examined contracted dengue 6 months after receiving the vaccine.

The fatalities had internal bleeding, enlarged organs and petechial rashes. One of them died within 24 hours after experiencing dengue symptoms, he told radio DZMM.

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"'Pag nakakita po tayo ng pattern dito sa death ng mga batang ito, at risk na po ang ating mga kabataan na naka-receive ng vaccination -- that is more than 800,000. Unfortunately po, the last few days, nakakita na po kami ng pattern dito sa pagkamatay ng 4 po," Erfe said.

(If we see a pattern in the death of these children, this would mean that the kids who received the vaccination are at risk -- that is more than 800,000. Unfortunately, we have seen a pattern in the death of 4 kids so far.)

PAO, he said, is set to examine the bodies 3 other children, as requested by their parents.

The group has also referred to the hospital 21 Dengvaxia recipients, including a pregnant 15-year-old girl, who had rashes, a common dengue symptom.

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Health Secretary Francisco Duque III told ABS-CBN News website that he welcomes PAO findings, but that this would need to be verified by a panel of experts tapped by the government.

The health agency, he added, is ready to assist PAO in their investigation.

PAO chief Persida Rueda-Acosta however earlier rejected the offer of help, claiming that the experts allegedly have ties with Sanofi, which Duque has denied.

Dr. Antonio Dans, an epidemiologist from the University of the Philippines, earlier warned that Dengvaxia could act like a primary infection for those who had never had dengue.

If they were bitten by a mosquito carrying the virus after the vaccination, it could allegedly be akin to getting dengue a second time, which often leads to far more severe symptoms and potentially death if bad cases are not treated quickly, he said.

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Sanofi has said that only 1 out of 10 Filipinos have no prior history of dengue and were the only ones facing the risk of contracting severe dengue.

This projection however means that 10 percent or some 80,000 of the 800,000 schoolchildren who received the vaccine may not have had dengue and are therefore exposed to greater health risks, Dans said.

The issue has triggered separate probes by the Senate, House of Representatives and National Bureau of Investigation.