Genotype II Live-Attenuated ASFV Vaccine Strains Unable to Completely Protect Pigs against the Emerging Recombinant ASFV Genotype I/II Strain in Vietnam
Nguyen Van Diep,
Nguyen Van Duc,
Nguyen Thi Ngoc,
Vu Xuan Dang,
Tran Ngoc Tiep,
Viet Dung Nguyen,
Thi Tam Than,
Dustin Maydaniuk,
Kalhari Goonewardene,
Aruna Ambagala,
Van Phan Le
Affiliations
Nguyen Van Diep
AVAC Vietnam Joint Stock Company, Ngoc Lich Village, Trung Trac Commune, Van Lam District, Hung Yen 160000, Vietnam
Nguyen Van Duc
AVAC Vietnam Joint Stock Company, Ngoc Lich Village, Trung Trac Commune, Van Lam District, Hung Yen 160000, Vietnam
Nguyen Thi Ngoc
AVAC Vietnam Joint Stock Company, Ngoc Lich Village, Trung Trac Commune, Van Lam District, Hung Yen 160000, Vietnam
Vu Xuan Dang
AVAC Vietnam Joint Stock Company, Ngoc Lich Village, Trung Trac Commune, Van Lam District, Hung Yen 160000, Vietnam
Tran Ngoc Tiep
AVAC Vietnam Joint Stock Company, Ngoc Lich Village, Trung Trac Commune, Van Lam District, Hung Yen 160000, Vietnam
Viet Dung Nguyen
Faculty of Animal Science and Veterinary Medicine, Bac Giang Agriculture and Forestry University, Bac Giang 230000, Vietnam
Thi Tam Than
College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 100000, Vietnam
Dustin Maydaniuk
Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada
Kalhari Goonewardene
Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada
Aruna Ambagala
Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada
Van Phan Le
College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 100000, Vietnam
Background: African swine fever virus (ASFV) continues to spread globally, causing severe economic losses to pig farmers. Vietnam licensed two live attenuated vaccines based on the ASFV strains ASFV-G-ΔI177L and ASFV-G-ΔMGF to control the ongoing ASF outbreaks. In 2023, newly emerging highly virulent recombinant ASF viruses (rASFV I/II) containing genetic elements from both p72 genotype I and II ASF viruses were reported from Northern Vietnam. Objective: This study evaluated whether the two vaccine strains were able to protect the pigs against the emerging rASFV I/II strain VNUA/rASFV/TN1/23. Results: Pigs vaccinated with ASFV-G-ΔMGF or ASFV-G-ΔI177L, when challenged with rASFV I/II, succumbed to the infection, or developed signs of chronic ASF. Conclusions: The findings from this study show that both vaccine strains that are licensed and used in Vietnam are unlikely to protect pigs from the emerging highly virulent rASFV I/II. This complicates the ongoing efforts to control ASF in Asia and globally and emphasizes the urgent need for a novel vaccine that can effectively protect pigs from the rASFV I/II.
