Understanding the VHH Format: Structural and Functional Properties of Single-Domain Antibodies

Download our application note about the structural features, functional properties and therapeutic applications of VHH antibodies.

Abstract:

VHH antibodies have evolved from an alternative antibody format into an established therapeutic modality, with multiple approved medicines and a rapidly expanding clinical pipeline. Their small size, exceptional stability, long CDR3 loops and modular architecture allow them to reach targets and enable therapeutic designs that are often difficult to achieve with conventional antibodies. This application note provides a scientific overview of the VHH format, covering its structural adaptations, binding mechanisms, manufacturability and biophysical properties. It also explores how these characteristics support applications ranging from multi-specific antibodies and cell therapies to diagnostics and targeted delivery, while discussing practical considerations including half-life extension, immunogenicity and synthetic library design.

What You’ll Learn:

The structural features that distinguish VHH antibodies from conventional IgG and other single-domain antibody formats
How VHH framework adaptations improve stability, solubility and independent folding
Why long CDR3 loops enable recognition of cryptic and challenging epitopes
The relationship between VHH architecture and applications including multi-specifics, CAR-T, diagnostics and targeted payload delivery
Strategies to address key developability considerations, including half-life extension and humanisation
How synthetic VHH libraries can improve discovery efficiency while supporting manufacturability and freedom to operate

Why it matters:

Selecting the right antibody format is one of the earliest strategic decisions in any biologics discovery programme. Understanding the strengths and limitations of VHH antibodies helps teams evaluate whether a single-domain approach can reduce discovery risk, improve developability, or enable target biology that may be difficult to address with conventional antibody formats.

Whether you are exploring difficult targets, designing multi-specific therapeutics or evaluating platform technologies, this application note provides the scientific context needed to make more informed decisions about the role of VHH antibodies in your discovery strategy.