Targets for developing recombinant protein based veterinary vaccines

Table of Contents

Developing recombinant protein-based vaccines for pets is a promising approach to reduce reactogenicity and side effects compared to traditional inactivated vaccines. Below are key diseases and strategic suggestions for our focus:

1. High-Priority Diseases with Existing Vaccine Limitations

Feline Leukemia Virus (FeLV)
Rationale: Current vaccines may have variable efficacy and occasional side effects.
Target Antigen: Recombinant envelope protein (p45) or novel fusion proteins.
Advantage: Improved safety and longer-lasting immunity for high-risk cats (outdoor/multi-cat households).
Canine Lyme Disease (Borrelia burgdorferi)
Rationale: Existing OspA-based vaccines may lack coverage against emerging strains.
Target Antigen: Recombinant chimeric OspA/OspC proteins or conserved epitopes.
Advantage: Broader protection and reduced risk of vaccine-associated arthritis.
Leptospirosis
Rationale: Inactivated vaccines target limited serovars and have short-lived immunity.
Target Antigen: Recombinant conserved outer membrane proteins (e.g., LipL32) or multi-serovar cocktails.
Advantage: Enhanced cross-protection and reduced hypersensitivity reactions.

2. Diseases with No/Underdeveloped Vaccines

Feline Infectious Peritonitis (FIP)
Rationale: No effective vaccine exists; high mortality in cats.
Target Antigen: Recombinant spike (S) protein of feline coronavirus (mutated for immune evasion).
Challenge: Balance immunity without triggering antibody-dependent enhancement (ADE).
Canine Leishmaniasis
Rationale: Existing vaccines have limited efficacy against this zoonotic protozoan disease.
Target Antigen: Recombinant Leishmania antigens (e.g., gp63, LACK) to stimulate Th1 immunity.
Advantage: Prophylactic and therapeutic potential in endemic regions.

3. Maternal Antibody Interference Challenges

Canine Parvovirus (CPV) and Distemper
Rationale: Live vaccines can be neutralized by maternal antibodies in puppies.
Target Antigen: Recombinant VP2 (CPV) or F/H proteins (distemper) with adjuvants to bypass interference.
Advantage: Enable earlier, safer vaccination in young animals.

4. Zoonotic and Emerging Pathogens

Rabies
Rationale: Inactivated vaccines are safe but may cause local reactions.
Target Antigen: Recombinant glycoprotein G (as used in oral wildlife vaccines).
Advantage: Safer booster vaccines for pets, especially in sensitive individuals.
Canine Influenza (H3N8/H3N2)
Rationale: Strain-specific vaccines limit coverage.
Target Antigen: Recombinant hemagglutinin (HA) proteins from multiple strains.
Advantage: Broad-spectrum protection against evolving strains.

5. Highly Variable or Underaddressed Pathogens

Feline Calicivirus (FCV)
Rationale: Current vaccines struggle with viral diversity.
Target Antigen: Recombinant VP1 capsid proteins targeting conserved regions.
Advantage: Cross-protection against multiple FCV strains.
Giardiasis
Rationale: Limited vaccine uptake due to modest efficacy.
Target Antigen: Recombinant cyst wall proteins or variable surface proteins (VSPs).
Advantage: Mucosal immunity to reduce shedding and zoonotic risk.

Strategic Considerations

Adjuvant Selection: Pair antigens with novel adjuvants (e.g., TLR agonists) to enhance immune responses without inflammation.
Combination Vaccines: Develop multi-antigen vaccines (e.g., Lyme + leptospirosis) to simplify pet healthcare.
Market Focus: Prioritize diseases with high owner awareness (e.g., rabies, Lyme) or unmet needs (e.g., FIP, leishmaniasis).
Regulatory Pathways: Collaborate with veterinary agencies to streamline approval for recombinant platforms.

By targeting these areas, the recombinant protein vaccines could address critical gaps in safety, efficacy, and coverage, offering a competitive edge in the pet vaccine market.