Virus inactivation at moderately low pH varies with virus and buffer properties

Area of Science:

• Biotechnology
• Virology
• Process Chemistry

Background:

• Virus inactivation is crucial for therapeutic protein manufacturing.
• Low pH buffers are standard for enveloped virus clearance.
• Model virus selection impacts viral clearance study outcomes.

Purpose of the Study:

• Compare inactivation susceptibility of Pseudorabies virus (SuHV), herpes simplex virus-1 (HSV-1), and equine arteritis virus (EAV) at low pH.
• Evaluate the efficacy of glycine, acetate, and citrate buffers.
• Determine the impact of buffer strength on virus inactivation.

Main Methods:

• Tested SuHV, HSV-1, and EAV inactivation at pH 4.0 and 4°C.
• Utilized glycine, acetate, and citrate buffers at varying strengths.
• Assessed viral infectivity post-treatment.

Main Results:

• Inactivation susceptibility order: SuHV > HSV > EAV.
• Buffer effectiveness order: citrate > acetate > glycine.
• Equine arteritis virus (EAV) showed stability and infectivity across all tested conditions.

Conclusions:

• Pseudorabies virus (SuHV) and herpes simplex virus-1 (HSV-1) exhibit differential inactivation, precluding their interchangeable use as virus models.
• Smaller enveloped viruses like EAV may retain infectivity under moderately low pH conditions.