The Philippines is under global scrutiny as it proceeds with the controlled rollout of an unproven African swine fever (ASF) vaccine from Vietnam amid doubts from experts about its safety and efficacy . ASF is a highly contagious viral disease that affects domestic and wild pigs and has a mortality rate that can reach 100 per cent, according to the World Organisation for Animal Health (WOAH). There is no internationally approved vaccine against the virus which has led to huge losses in pig populations following an upsurge in the disease since 2022.
“There is a very big concern,” said Ramon Clarete, a professor of economics at the University of the Philippines Diliman who specialises in agricultural productivity. “We really must be careful about this [vaccine], because the swine industry is a very important industry in agriculture.” The concerns stem from a perceived lack of transparency from Vietnam about its trial data and the nature of the ASF vaccine, which consists of a live virus that has been weakened by deleting important parts of its genes.
This type, called a live-attenuated vaccine, may still pose a serious risk of mutation and reversion to its viral form. “The risk with a live-attenuated vaccine is that it may still have a little bit of virulence that can cause either the disease or some form of discomfort or disease,” said Baptiste Dungu, professor at University of Kinshasa, Democratic Republic of Congo and vaccinologist with more than 30 years in vete.