A Next-Generation Human Lymphatic Filariasis Vaccine Candidate, rBmHAXT, for Clinical Development.

Area of Science:

• Tropical medicine
• Vaccine development
• Parasitic diseases

Background:

• Lymphatic filariasis (LF) is a tropical parasitic infection transmitted by mosquitoes.
• Previous vaccine candidates faced challenges with antigen aggregation during scaled-up production.
• Optimizing manufacturing processes is crucial for vaccine efficacy and scalability.

Purpose of the Study:

• To develop a scalable manufacturing process for a robust lymphatic filariasis (LF) vaccine candidate.
• To engineer new forms of the rBmHAXT antigen to improve industrial-scale production.
• To maintain vaccine immunogenicity and efficacy while addressing aggregation issues.

Main Methods:

• Generated three rBmHAXT variants: delta-Cys (cysteine to serine mutation), GS (glycine-serine linker insertion), and delta-Cys GS (combination).
• Evaluated immunogenicity and efficacy of variants in a mouse model.
• Assessed accelerated stability of protein variants at various temperatures (-80°C to 40°C).

Main Results:

• The delta-Cys mutant demonstrated immunogenicity and vaccine efficacy comparable to the parent tag-free rBmHAXT.
• All protein preparations were stable at 4°C.
• The delta-Cys variant exhibited stability at 25°C for 6 weeks, with reduced aggregation and equivalent potency in mice.

Conclusions:

• The delta-Cys variant is a promising candidate for lymphatic filariasis (LF) vaccine development due to improved stability and reduced aggregation.
• This variant is suitable for progression to current Good Manufacturing Practice (cGMP) manufacturing.
• The findings support the advancement of this optimized vaccine candidate into human clinical trials.