ASFV-G- increment I177L as an Effective Oral Nasal Vaccine against the Eurasia Strain of Africa Swine Fever

The African swine fever virus (ASFV) is currently causing a pandemic affecting wild and domestic swine from Western Europe to Asia. No commercial vaccines are available to prevent African swine fever (ASF), resulting in overwhelming economic losses to the swine industry. We recently developed a recombinant vaccine candidate, ASFVG-Delta I177L, by deleting the I177L gene from the genome of the highly virulent ASFV strain Georgia (ASFV-G). ASFV-G-Delta I177L has been proven safe and highly efficacious in challenge studies using parental ASFV-G. Here, we present data demonstrating that ASFV-G-Delta I177L can be administered by the oronasal (ON) route to achieve a similar efficacy to that of intramuscular (IM) administration. Animals receiving ON ASFV-G-Delta I177L were completely protected against virulent ASFV-G challenge. As previously described, similar results were obtained when ASFV-G-Delta I177L was given intramuscularly. Interestingly, viremias induced in animals inoculated oronasally were lower than those measured in IM-inoculated animals. ASFV-specific antibody responses, mediated by IgG1, IgG2 and IgM, do not differ in animals inoculated by the ON route from that had IM inoculations. Therefore, the ASFV-G-Delta I177L vaccine candidate can be administered oronasally, a critical attribute for potential vaccination of wild swine populations.