Source 1primary paper2025MED
Toolkit/FPV VLP vaccine
FPV VLP vaccine
Also known as: FPV virus-like particles, FPV VLP vaccine
Taxonomy: Mechanism Branch / Architecture. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
This study aimed to produce FPV virus-like particles (VLPs) using a recombinant baculovirus system expressing the VP2 gene and evaluate their immunogenicity and protective efficacy in cats.
Usefulness & Problems
Why this is useful
This is an FPV VP2-based virus-like particle vaccine produced in insect cells using recombinant baculovirus. The abstract reports that it induces HI and VN antibodies and protects cats against virulent FPV challenge.; FPV vaccine development; inducing antibody responses in cats; protective immunization against virulent FPV challenge
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This is an FPV VP2-based virus-like particle vaccine produced in insect cells using recombinant baculovirus. The abstract reports that it induces HI and VN antibodies and protects cats against virulent FPV challenge.
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FPV vaccine development
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inducing antibody responses in cats
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protective immunization against virulent FPV challenge
Problem solved
The study positions the VLP vaccine as a safer and more efficient alternative to existing FPV vaccines. It is intended to prevent feline panleukopenia while avoiding some production and safety issues of current vaccines.; providing a potentially safer vaccine candidate for feline panleukopenia; offering an alternative to current vaccines described as complex, costly, and carrying safety risks
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The study positions the VLP vaccine as a safer and more efficient alternative to existing FPV vaccines. It is intended to prevent feline panleukopenia while avoiding some production and safety issues of current vaccines.
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providing a potentially safer vaccine candidate for feline panleukopenia
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offering an alternative to current vaccines described as complex, costly, and carrying safety risks
Problem links
offering an alternative to current vaccines described as complex, costly, and carrying safety risks
LiteratureThe study positions the VLP vaccine as a safer and more efficient alternative to existing FPV vaccines. It is intended to prevent feline panleukopenia while avoiding some production and safety issues of current vaccines.
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The study positions the VLP vaccine as a safer and more efficient alternative to existing FPV vaccines. It is intended to prevent feline panleukopenia while avoiding some production and safety issues of current vaccines.
providing a potentially safer vaccine candidate for feline panleukopenia
LiteratureThe study positions the VLP vaccine as a safer and more efficient alternative to existing FPV vaccines. It is intended to prevent feline panleukopenia while avoiding some production and safety issues of current vaccines.
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The study positions the VLP vaccine as a safer and more efficient alternative to existing FPV vaccines. It is intended to prevent feline panleukopenia while avoiding some production and safety issues of current vaccines.
Published Workflows
Objective: Produce FPV VP2-based virus-like particles using a recombinant baculovirus expression system and evaluate their immunogenicity and protective efficacy in cats.
Why it works: The workflow first generates and confirms assembled FPV VLPs, then tests whether those particles induce antibody responses and protect cats from virulent challenge. The paper frames this as a route to a safer and more efficient alternative to current vaccines.
VP2-based self-assembly into virus-like particlesinduction of HI and virus-neutralizing antibody responsesrecombinant baculovirus expression in Sf9 cellsprotein purification by ultrafiltration and SECparticle characterization by DLS and TEManimal immunization and virulent challenge
Stages
- 1.VLP production and purification(library_build)
This stage generates the FPV VP2 material needed to form the vaccine candidate before characterization and animal testing.
Selection: Expression of VP2 in Sf9 insect cells followed by purification of VP2 material.
- 2.Particle assembly confirmation(functional_characterization)
This stage verifies that the expressed and purified VP2 formed virus-like particles before proceeding to animal immunization.
Selection: Confirmation of VLP assembly by DLS and TEM.
- 3.Cat immunization and serologic readout(secondary_characterization)
This stage tests whether the VLP vaccine induces measurable antibody responses in the target animal species before challenge.
Selection: Comparison of HI and VN antibody responses between vaccinated and PBS control cats.
- 4.Virulent challenge validation(confirmatory_validation)
This stage confirms whether vaccination translates into protection against virulent FPV infection in cats.
Selection: Protection from clinical signs and maintenance of white blood cell counts after virulent FPV strain 708 challenge.
Steps
- 1.Express VP2 in Sf9 insect cells using recombinant baculovirusengineered vaccine material being produced
Generate FPV VP2 protein for VLP formation.
VP2 expression is required before purification, assembly confirmation, and animal testing can occur.
- 2.Purify VP2 material by ultrafiltration and SECvaccine material being purified
Obtain purified VP2/VLP material for downstream assembly confirmation and immunization.
Purification follows expression so that the material can be characterized and used as vaccine input.
- 3.Confirm VLP assembly by DLS and TEMvaccine construct being characterized
Verify that the purified VP2 material formed virus-like particles.
Assembly confirmation is performed before animal immunization to ensure the intended VLP product was generated.
- 4.Immunize cats with three VLP dose levels and collect day-21 blood samplesvaccine administered to animals
Test dose-dependent immunization in cats and prepare for serologic assessment.
Animal dosing must precede antibody measurement and challenge testing.
- 5.Measure HI and VN antibody responsesassays used to evaluate vaccine response
Assess immunogenicity of the FPV VLP vaccine before challenge.
Serologic testing follows immunization and provides a pre-challenge readout of vaccine-induced antibody responses.
- 6.Challenge the 15 bcg dose group with virulent FPV strain 708 and monitor disease outcomesvaccine previously administered to challenged animals
Determine whether vaccination protects cats from virulent FPV disease.
Challenge is performed after immunization and serologic assessment to test whether the vaccine confers functional protection.
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Architecture: A reusable architecture pattern for arranging parts into an engineered system.
Mechanisms
antigen presentation by vp2-based particulate immunogenhumoral immunization inducing hemagglutination-inhibiting and virus-neutralizing antibodiesvirus-like particle self-assemblyTechniques
No technique tags yet.
Target processes
No target processes tagged yet.
Input: Light
Implementation Constraints
cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: spectral hardware requirementoperating role: actuator
The reported production workflow uses recombinant baculovirus, Sf9 insect cells, ultrafiltration, SEC, DLS, and TEM. In vivo evaluation also requires cat immunization, serology, and challenge testing.; requires recombinant baculovirus expression of VP2 in Sf9 insect cells; requires purification by ultrafiltration and SEC; requires particle characterization by DLS and TEM for assembly confirmation
The abstract does not show whether the vaccine protects against divergent FPV or CPV-related strains, nor whether protection is durable beyond the short challenge window. It also does not establish manufacturing scalability or cost in practice.; challenge efficacy in the abstract is described only for the 15 bcg dose group; abstract does not report adjuvant formulation, durability, or heterologous strain protection
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Observations
successLarge Animalapplication democat
serology
Inferred from claim c2 during normalization. Immunization with the FPV VLP vaccine produced significantly higher HI and VN antibody titers than PBS control in cats. Derived from claim c2. Quoted text: Immunized cats exhibited significantly higher HI and VN antibody titers compared to controls.
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successLarge Animalapplication democatvirulent FPV strain 708 challenge
challenge study
Inferred from claim c3 during normalization. The FPV VLP vaccine protected challenged cats from clinical disease and leukopenia after virulent FPV strain 708 challenge. Derived from claim c3. Quoted text: Cats in the 15 bcg dose group were challenged with virulent FPV strain 708 on day 21, and clinical signs and white blood cell counts were monitored for 10 days. After challenge, vaccinated cats showed no clinical signs of disease, and their white blood cell counts remained stable.
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challenge monitoring duration10 days
successLarge Animalapplication democatvirulent FPV strain 708 challenge
challenge study
Inferred from claim c4 during normalization. PBS control cats developed severe symptoms and significant leukopenia after virulent FPV challenge, unlike vaccinated cats. Derived from claim c4. Quoted text: In contrast, control cats developed severe symptoms and experienced significant leukopenia.
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Supporting Sources
Ranked Claims
PBS control cats developed severe symptoms and significant leukopenia after virulent FPV challenge, unlike vaccinated cats.
In contrast, control cats developed severe symptoms and experienced significant leukopenia.
An FPV VLP vaccine was produced using a recombinant baculovirus system expressing VP2 in Sf9 insect cells, and VLP assembly was confirmed by DLS and TEM.
Sf9 insect cells were infected with recombinant baculovirus to express VP2 protein. The VP2 protein was purified using ultrafiltration and size-exclusion chromatography (SEC). Dynamic light scattering (DLS) and transmission electron microscopy (TEM) confirmed the assembly of VLPs.
Immunization with the FPV VLP vaccine produced significantly higher HI and VN antibody titers than PBS control in cats.
Immunized cats exhibited significantly higher HI and VN antibody titers compared to controls.
The FPV VLP vaccine protected challenged cats from clinical disease and leukopenia after virulent FPV strain 708 challenge.
Cats in the 15 bcg dose group were challenged with virulent FPV strain 708 on day 21, and clinical signs and white blood cell counts were monitored for 10 days. After challenge, vaccinated cats showed no clinical signs of disease, and their white blood cell counts remained stable.
challenge monitoring duration 10 days
Approval Evidence
1 source4 linked approval claimsfirst-pass slug fpv-vlp-vaccine
This study aimed to produce FPV virus-like particles (VLPs) using a recombinant baculovirus system expressing the VP2 gene and evaluate their immunogenicity and protective efficacy in cats.
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comparative outcomesupports
PBS control cats developed severe symptoms and significant leukopenia after virulent FPV challenge, unlike vaccinated cats.
In contrast, control cats developed severe symptoms and experienced significant leukopenia.
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engineering outcomesupports
An FPV VLP vaccine was produced using a recombinant baculovirus system expressing VP2 in Sf9 insect cells, and VLP assembly was confirmed by DLS and TEM.
Sf9 insect cells were infected with recombinant baculovirus to express VP2 protein. The VP2 protein was purified using ultrafiltration and size-exclusion chromatography (SEC). Dynamic light scattering (DLS) and transmission electron microscopy (TEM) confirmed the assembly of VLPs.
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immunogenicitysupports
Immunization with the FPV VLP vaccine produced significantly higher HI and VN antibody titers than PBS control in cats.
Immunized cats exhibited significantly higher HI and VN antibody titers compared to controls.
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protective efficacysupports
The FPV VLP vaccine protected challenged cats from clinical disease and leukopenia after virulent FPV strain 708 challenge.
Cats in the 15 bcg dose group were challenged with virulent FPV strain 708 on day 21, and clinical signs and white blood cell counts were monitored for 10 days. After challenge, vaccinated cats showed no clinical signs of disease, and their white blood cell counts remained stable.
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Comparisons
Source-stated alternatives
The abstract contrasts this candidate with current FPV vaccines in general rather than naming a specific comparator vaccine. The upstream summary also notes recombinant CAV-2 expressing FPV VP2 as an alternative VP2-based delivery platform, but that is not tested in this paper.
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The abstract contrasts this candidate with current FPV vaccines in general rather than naming a specific comparator vaccine. The upstream summary also notes recombinant CAV-2 expressing FPV VP2 as an alternative VP2-based delivery platform, but that is not tested in this paper.
Source-backed strengths
assembled as VLPs confirmed by DLS and TEM; elicited higher HI and VN antibody titers than PBS controls; protected challenged cats from clinical disease and leukopenia
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assembled as VLPs confirmed by DLS and TEM
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elicited higher HI and VN antibody titers than PBS controls
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protected challenged cats from clinical disease and leukopenia
Compared with mMORp
FPV VLP vaccine and mMORp address a similar problem space.
Shared frame: same top-level item type; same primary input modality: light
Compared with optogenetic probes
FPV VLP vaccine and optogenetic probes address a similar problem space.
Shared frame: same top-level item type; same primary input modality: light
Compared with organoid fusion
FPV VLP vaccine and organoid fusion address a similar problem space.
Shared frame: same top-level item type; same primary input modality: light
Ranked Citations
- 1.