The 2017 dengue vaccine controversy in the Philippines involved a vaccination program run by the Phillipine Department of Health and vaccinated school children with Dengvaxia. Some of the children who received the vaccine have never been infected by the dengue virus before.

These children were found to be at risk of developing severe dengue disease with subsequent infection by the virus. The vaccination problem was subsequently terminated after the vaccine manufacturers, Sanofi-Pasteur released a statement stating that Dengvaxia posed risks to individuals vaccinated without having a prior dengue infection.

Rapid Dengue Testing Singapore

Subsequent analysis noted that vaccine efficacy among patients with previous dengue infection proven on blood tests is around 76%, while for patients without any prior dengue infection is around 38.8%. There is also an increased risk of hospitalization and severe dengue in these individuals starting around 30 months after the first dose. 

The postulated reason why Dengvaxia causes severe dengue in unvaccinated patients is due to a phenomenon known as Antibody Dependent Enhancement (ADE). ADE is the consequence of secondary Dengue Infection with a different subtype and the pre-existing antibodies from the first infection causes severe disease which involves shock and bleeding. It appears that the use of Dengvaxia can lead to ADE.

For patients with previous dengue infection and are willing to go ahead with a blood test for antibodies, it can be definitely useful as we live in Dengue Endemic Singapore. However, for patients without any previous dengue infection, preventive measures like eradication of breeding sites and wearing repellent might still be a better option.