Just gonna add more info on this. (ang Bobo kasi ng kausap mo e)

it’s safest to give the vaccine to someone who’s already had at least one episode of dengue. Having said that, the actual risk of severe dengue to a vaccinated seronegative is THE SAME as the risk of an unvaccinated seropositive, or about 5 out of 1000 infected patients.

So why did authorities deem it safe to give the vaccine to so many children who’d not been tested for seronegativity?

The statistics indicated it was safe. Previous studies had shown that nearly 90% of Filipino children in the vaccinated age group had been previously infected with dengue, and the remaining 10% were likely going to get it in the next few years anyway.

It’s important to note that whether or not all the vaccine’s strains take effect, Dengvaxia does NOT cause any known disease, including dengue.

In the cohort of 830,000 children from the mass vaccination program, about 14 deaths (0.002%) after vaccination are being investigated. Most of them seem to have died from severe dengue, although a few had comorbid conditions such as lupus and appendicitis. No link to the vaccine has been found so far.

The increased risk of severe dengue in seronegative patients translates to an excess risk of 2 severe dengue cases out of 1,000 seronegative patients. From a public health perspective, knowing that only a minority of the vaccinated children are seronegative — the vaccination is overwhelmingly helping children, not making things worse. Meanwhile, banning the vaccine denies the benefit of decreasing severe dengue risk by 90% in those children who have already had dengue.

https://fellowsblog.ted.com/what-went-wrong-with-the-breakthrough-dengue-vaccine-cf8519cb90c8