MA-104 cell based live attenuated African Swine Fever virus (ASFV) vaccine for Pigs

Background

African Swine Fever (ASF), caused by African swine fever virus (ASFV), is a highly contagious and fatal viral disease of domestic pigs and wild boars worldwide. The disease has a significant economic impact, and is characterized by high fever, haemorrhages, with a mortality rate up to 100% in pigs. In India, ASF in pigs was first reported in 2020 and the outbreaks were caused by the ASFV Genotype-II, which is the predominant genotype responsible for most of the contemporary ASF outbreaks worldwide. ASF is widely prevalent in India, and large-scale mortality among domestic pigs and wild boars has a devastating economic impact on swine industry and rural livelihoods. However, vaccine against ASF is not available in India. Moreover, globally there is limited success in development of effective vaccine against ASF, except for two laboratory-generated mutant-based vaccines developed through homologous recombination, based on deletion of a limited number of viral genes and its propagation in patented cell lines. Furthermore, the current ASF control strategy in India relies on culling, movement restrictions, and biosecurity measures, which is economically unsustainable. Hence, there is a pressing need of an indigenously developed vaccine against ASF in pigs.

Technology Details

The NIHSAD MA-104 cell adapted live attenuated ASFV vaccine for domestic pigs is based on an Indian field isolate (ASFV/Ind/NIHSAD/Sw-2022/1055) for the prevention and control of ASF in pigs. The vaccine is administered as a 1 mL intramuscular dose containing 10³ HAD₅₀/mL into the neck muscles of pigs, followed by a booster dose 14 days after primary vaccination. Vaccine safety and efficacy studies in experimental pig trial has shown promising results, as evident by complete protection against virulent ASFV genotype-II challenge and no reversion to virulence upon passage in pigs. The ASFV specific antibodies are detectable up to six months following the primary dose. The vaccine is recommended for healthy, non-pregnant pigs aged more than 8 weeks. Besides, the candidate vaccine virus grows to a high titre in heterologous MA-104 cells, and thus has several advantages over vaccines using gene-deleted mutant strains generated through homologous recombination containing exogenous genes of non-viral origin.  This is the first indigenously developed live attenuated ASFV vaccine, which will help in prevention and control of ASF in pigs not only in India but also globally, improving the profitability of the swine industry and livelihood security of pig farmers in India. In addition, Indian Patent application and PCT international application have been filed for this technology.