PRRSV Minor Protein Adenovirus Vectors for Safer Broad Protection

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Solution Overview

Problem

Current PRRSV vaccines, particularly recombinant vaccines based on major envelope proteins, fail to provide broad protection against various viral variants and are either unsafe or ineffective, with live vaccines risking reversion to wild-type and killed vaccines offering limited efficacy.

Innovation Solution

Development of recombinant adenovirus-vectored vaccines expressing PRRSV minor proteins gp2, gp3, and gp4, with modifications to ensure cell-surface expression, using vectors like Ad5, baculovirus, or poxvirus, to form protective protein complexes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If attenuated modified live virus vaccines are used, then effective protection against homologous challenge is achieved, but safety deteriorates due to potential reversion to wild-type and inability to achieve PRRSV-free status

Engineering Contradiction:
Improveprotection efficacyVSAvoidsafety risks
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts only the essential immunogenic components (minor envelope proteins gp2, gp3, gp4) from the complete live virus, eliminating the replication-competent genome while retaining the protective antigens. This creates a subunit vaccine that provides immunogenicity without the safety risks of live virus reversion.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses an adenovirus vector as an intermediary delivery system to present the PRRSV minor proteins to the immune system. This mediator approach allows the antigens to be delivered and expressed in a controlled manner without using the actual PRRSV live virus, thus avoiding safety risks while maintaining efficacy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If killed virus vaccines are used, then safety is improved, but protection efficacy deteriorates due to limited immunogenicity

Engineering Contradiction:
ImprovesafetyVSAvoidprotection efficacy
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the molecular form and presentation of the viral antigens by expressing minor envelope proteins as recombinant fusion proteins with cell surface localization signals. This parameter change in antigen structure and cellular localization enhances immunogenicity significantly compared to traditional killed whole virus vaccines, achieving both safety and efficacy.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates composite antigen structures by fusing PRRSV minor proteins with heterologous cell surface localization sequences (such as VSV-G transmembrane and cytoplasmic domains). These composite proteins are then presented on the surface of transfected cells, creating a composite vaccine system that combines safety with enhanced immunogenicity.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If recombinant vaccines based on major envelope proteins are used, then ease of manufacture is improved, but protection efficacy deteriorates due to lack of broad protection against variants

Engineering Contradiction:
Improveproduction feasibilityVSAvoidbroad protection
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

Instead of focusing on the major envelope proteins (gp5, M) as traditionally done, the patent inverts the approach by targeting the minor envelope proteins (gp2, gp3, gp4). This inversion reveals that the minor proteins, which are more conserved and mediate receptor binding, provide broader cross-protection against different PRRSV variants while remaining feasible to produce recombinantly.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP3889166B1Prrsv minor protein-containing recombinant viral vectors and methods of making and use thereof
Publication Date: 2025.08.06 BOEHRINGER INGELHEIM VETMEDICA GMBH
  • EP3889166B1 patent drawingFigure 1A~1D
  • EP3889166B1 patent drawingFigure 1E~1G
  • EP3889166B1 patent drawingFigure 2~3

AI summary

The present invention encompasses recombinant porcine reproductive and respiratory syndrome virus (PRRSV) vaccines or compositions. In particular, the invention encompasses recombinant adenovirus vectors encoding and expressing PRRSV gp2, gp3, gp4, gp5a, gp5 and/or E antigens, proteins, epitopes or immunogens. Such vaccines or compositions can be used to protect animals from PRRSV.