The Department of Agriculture (DA) on Tuesday acknowledged that while some African swine fever or ASF-infected pigs died post-vaccination, the majority remain in good health as a result of tests conducted in Lobo, Batangas.
The DA said the 30-day post-vaccination period is critical in assessing its effectiveness in ensuring the health of the remaining pigs that received live attenuated vaccines developed in Vietnam.
The agency said the polymerase chain reaction (PCR) tests on deceased pigs confirmed ASF infection but noted that since the attenuated vaccine can also be detected by PCR, additional diagnostic tests are underway.
Constante Palabrica, DA assistant secretary for swine and poultry, said enzyme-linked immunoassay (ELISA) tests were conducted to measure the immune response by detecting antibody levels. An increase in percentage blocking, he said, suggests stronger immunity for the vaccinated hogs.
“The ELISA test results showed the presence of antibodies against ASF in some pigs, indicating they are building immunity. All remaining pigs are healthy and under close observation, Palabrica said.
He also said that differentiating infected from vaccinated animals (DIVA) tests are also in progress.
“The DIVA test distinguishes between vaccinated pigs and those infected with the field virus, which will help determine if the virus in the deceased pigs is linked to the vaccine or external sources,” Palabrica said.
“Vaccination is crucial, but it must be accompanied by stringent biosecurity practices to prevent further outbreaks. Honest and timely reporting from farmers is essential for the program’s success,” Palabrica stressed.
Palabrica likeise said that thus far, the vaccinated pigs are producing the expected number of antibodies after receiving the vaccine at 40 percent after 14 days and 90 percent after 30 days.
Given this development, Agriculture Secretary Francisco Tiu Laurel Jr. on Tuesday reaffirmed the agency’s commitment to find a long-term ASF solution and expressed optimism of the vaccine’s potential.
“These initial results are part of a broader effort to protect our swine population. We remain hopeful but cooperation from all stakeholders is vital. Strict adherence to vaccination protocols and biosecurity measures is crucial,” Tiu Laurel said.
As of 6 September this year, active ASF cases remain contained in 14 regions, 31 provinces, 109 municipalities and 472 barangays, the Bureau of Animal Industry reported.
