African swine fever (ASF) is a contagious viral disease that causes severe economic losses in the global swine industry. Since its introduction to Vietnam in 2019, ASFV has evolved rapidly, with genotype II strains dominating initially and recombinant I/II variants emerging by 2023. Live attenuated vaccines (LAVs) have been developed and commercialized in Vietnam, including ASFV-G-ΔI177L, ASFV-G-ΔI177L/ΔLVR, and ASFV-G-ΔMGF, which confer homologous immune protection. Despite this, LAVs face challenges related to genetic stability, impossible protection against emerging recombinant strains, potential reversion to virulence, viral shedding, and safety in pregnant sows. ASFV’s ongoing evolution underscores the need for continuous genomic surveillance, evaluation of cross-protective efficacy, and implementation of biosecurity and DIVA strategies focused more on evaluating vaccine efficacy than safety. This review summarizes the current molecular epidemiology of ASFV in Vietnam after vaccines were licensed for use, the development and performance of commercial LAVs, and the practical challenges of their application in endemic settings, and provides insights for informed vaccine deployment and integrated ASF control strategies in rapidly evolving viral landscapes.
Ngo et al. (Mon,) studied this question.