Recombinant FAdV-9 Vaccine Vector Stability and Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current recombinant adenovirus vaccines, particularly those using serotype-9 fowl adenovirus vectors, face challenges in stability during large-scale production and interference with Marek's disease vaccines, leading to suboptimal immune responses and short-term protection, while also being affected by maternal antibodies.
Innovation Solution
A recombinant vaccine using a serotype-9 fowl adenovirus vector with an exogenous nucleotide sequence inserted between specific genome regions (491-2782 nucleotides), which maintains stability through successive cell culture passes and does not interfere with Marek's disease vaccines, providing both early and lasting protection without maternal antibody interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fowl adenovirus vectors are used for recombinant vaccine production, then immune response is generated, but stability during successive cell culture passes is poor
Solution Approach 1:
The patent segments the adenovirus genome into essential and non-essential regions, inserting the heterologous gene specifically into the non-essential region (nucleotides 2783-490) while preserving essential regions for replication. This segmentation allows the viral vector to maintain stability during successive cell culture passes while still enabling large-scale production of the recombinant vaccine.
2Adaptability or versatility
If adenovirus vectors are administered with Marek's disease vaccine, then vaccine coverage is increased, but interference occurs reducing immune response
Solution Approach 1:
The patent extracts the heterologous gene encoding the desired antigen and inserts it into the adenovirus vector, separating the antigen expression function from the viral replication function. This allows the recombinant adenovirus vaccine to be co-administered with Marek's disease vaccine without interference, as the heterologous gene expression does not compete with the Marek's disease vaccine components for the same cellular machinery or immune pathways.
3Reliability
If maternal antibodies are present in newborn animals, then passive immunity is provided, but active vaccine response is suppressed
Solution Approach 1:
The patent employs a replication-defective adenovirus vector that expresses the heterologous antigen immediately upon infection, providing preliminary antigen exposure that stimulates active immune response. This preliminary action occurs despite the presence of maternal antibodies, as the defective vector cannot replicate but still delivers and expresses the antigen, initiating immune memory formation that persists beyond the waning of maternal antibody protection.
Data Source
AI summary
A recombinant vaccine comprising a serotype 9 fowl adenovirus vector (FAdV-9) having at least one exogenous nucleotide sequence inserted encoding at least one antigen of a disease of interest and replacing the adenovirus genome non-essential region, and a pharmaceutically acceptable vehicle, adjuvant and/or excipient, wherein the at least one exogenous nucleotide sequence encoding at least one antigen of a disease of interest and replacing the adenovirus genome non-essential region is located between the 491 and 2782 nucleotides. The vector of this vaccine is stable for industrial scale production. When administering this vaccine in combination with a vaccine against Marek's disease, both vaccines produce an adequate immune response which is not affected by interference between each other. In the same way, effectiveness of the recombinant vaccine is not affected by maternal antibodies, and is capable of inducing both an early and lasting protective response, even with only one application.