Lyophilization of ASFV vaccine candidate ASFV-G-ΔI177L offers long term stability

Area of Science:

• Veterinary Virology
• Vaccine Technology
• Animal Disease Control

Background:

• African swine fever (ASF) poses a significant threat to the global swine industry, causing substantial economic losses.
• Current ASF control strategies primarily involve culling and biosecurity, with limited vaccine options available.
• A novel ASFV vaccine, ASFV-G-ΔI177L, has recently been approved in Vietnam.

Purpose of the Study:

• To evaluate the long-term stability of the lyophilized ASFV-G-ΔI177L vaccine.
• To assess the vaccine's suitability for deployment in regions with unreliable cold chain infrastructure.
• To determine the impact of lyophilization and storage on the genetic integrity of the ASFV vaccine.

Main Methods:

• Lyophilization of the ASFV-G-ΔI177L vaccine under specific conditions.
• Storage of the lyophilized vaccine at 4°C for up to one year.
• Assessment of vaccine titers post-storage.
• Next-generation sequencing (NGS) analysis of the stored vaccine's genome.

Main Results:

• The lyophilized ASFV-G-ΔI177L vaccine demonstrated stability for one year when stored at 4°C.
• Vaccine titers remained comparable to the non-lyophilized form after the storage period.
• NGS analysis confirmed that lyophilization and storage did not induce any genetic alterations in the ASFV genome.

Conclusions:

• Lyophilized ASFV-G-ΔI177L is a stable vaccine formulation suitable for long-term storage at 4°C.
• The vaccine's genetic integrity is maintained after lyophilization and extended storage.
• This finding supports the potential deployment of the ASFV vaccine in diverse geographical areas, including those with limited cold chain capabilities.