French pharmaceutical giant Sanofi Pasteur said yesterday that there have been no reported deaths linked to its dengue vaccine, as the Philippines ordered a probe into an immunisation programme involving more than 730,000 children.
Non-governmental group Volunteers Against Crime and Corruption said it had information that three children in Luzon island who were vaccinated in April last year with Dengvaxia - the world's first vaccine for dengue - had died.
But Sanofi medical director Ruby Dizon said at a news conference: "As far as we know, there are no reported deaths related to dengue vaccination.
"If we try to create this misinformation, this will have an impact not only on the dengue vaccination but (also) the government's entire immunisation programme."
Dengue is the most widespread mosquito-borne disease in the world, with nearly 400 million infections every year.
Philippine health officials rolled out a 3.5 billion peso (S$93 million) vaccination programme using Dengvaxia in April last year, involving more than one million children.
At least 730,000 of them have received the first of three doses of the vaccine as of Nov 17. But the programme was suspended last Friday after an alert by Sanofi that its vaccine could prove harmful to people who have never been infected.
"For those not previously infected by dengue virus, the analysis found that in the longer term, more cases of severe disease could occur following vaccination upon a subsequent dengue infection." For those who had been infected, the vaccine could prevent repeat infection.
Dr Ng Su Peing, Sanofi's global medical head, said nine in 10 Filipinos will be exposed to the virus by the time they reach adolescence. Two-thirds, however, will not exhibit symptoms of the disease.
She said this means that 90 per cent of the population are unlikely to suffer a second, more severe type of dengue if they are vaccinated. "Severe dengue itself is rare," she said.
Dr Joselito Santa Ana, the company's regional director, said: "Let us put this in proper context. What is severe?... 'Severe' may just be two days of fever, lower platelet count, haematoma or vomiting."
Sanofi said overall, Dengvaxia has proven to be effective. It has prevented 65.5 per cent of dengue infections, and averted nine in 10 cases of severe dengue, according to Dr Ng.
Nevertheless, Justice Secretary Vitaliano Aguirre ordered a probe into whether Dengvaxia may be a danger to public health, and if those who approved its use should be charged.
Presidential spokesman Harry Roque said on Sunday: "We will leave no stone unturned in making those responsible for this shameless public health scam... accountable."
Sanofi said it would ask the authorities in countries where the vaccine has been approved for use, including Singapore, to update their information on the vaccine, and to disseminate it to doctors and patients.
A spokesman for Singapore's Health Sciences Authority said last week that it is working with Sanofi to "strengthen the package insert" to include the warning of an increased risk of hospitalisation for dengue and clinically severe dengue in vaccinated individuals not previously infected by dengue. It will also contain advisories on an assessment of prior dengue infection in individuals before vaccination, and that vaccination should not be recommended for those who have not had a dengue infection before.
