A 360,000-case gap: why no human Lyme disease vaccine exists yet
Lyme disease — caused by spirochetes of the Borrelia burgdorferi sensu lato complex and transmitted by Ixodes ticks — is the most common vector-borne infectious disease in North America and Europe, with the WHO and European Centre for Disease Control and Prevention estimating approximately 360,000 annual cases. Despite this burden, no licensed human vaccine currently exists, a gap that has driven intense patent and research activity over more than three decades. The pathogen complex encompasses B. burgdorferi sensu stricto, B. afzelii, and B. garinii — three genospecies with distinct geographic distributions and antigen profiles that together define the core design challenge for any broadly protective vaccine.
The disease manifests as a chronic, multi-system infection affecting skin, the central and peripheral nervous system, heart, liver, kidneys, and musculoskeletal system. This clinical breadth reflects the ability of Borrelia spirochetes to disseminate widely after tick transmission — and it underpins the commercial urgency for both prophylactic vaccines and post-infection treatment monitoring tools. Patent filings retrieved across the 1991–2025 period reveal a field that has matured from foundational monoclonal antibody approaches into a sophisticated multi-platform pipeline involving recombinant fusion proteins, mRNA, lipid antigens, and T-cell epitope engineering.
Anti-OspA antibodies act in the tick midgut during blood feeding, destroying Borrelia spirochetes before they enter the mammalian host. This means OspA-targeting vaccines prevent infection at the tick stage — a fundamentally different mechanism from vaccines that neutralise a pathogen already circulating in the human body.
The dominant antigen targets identified across retrieved patent records are OspA (Outer Surface Protein A, 31 kD), OspC (Outer Surface Protein C), OspB (34 kD), synthetic glycolipid antigens BBGL-1 and BBGL-2, and the VlsE-derived C6 diagnostic peptide. OspA’s predominance reflects its expression during tick-stage colonisation and the well-characterised bactericidal activity of anti-OspA antibodies — properties confirmed across multiple patent documents spanning three decades.
The WHO and European Centre for Disease Control and Prevention estimate approximately 360,000 annual cases of Lyme disease in North America and Europe, making it the most common vector-borne infectious disease in those regions. No licensed human Lyme disease vaccine currently exists as of 2025.
VLA15 and the multivalent OspA fusion protein approach
VLA15, co-developed by Pfizer and Valneva, is the only Lyme disease vaccine candidate currently in Phase 3 clinical trials — the most advanced human Lyme vaccine identified in the patent dataset. The candidate is built on a three-component lipidated OspA fusion protein composition, with each component a chimeric molecule pairing the distal domain of one OspA serotype with that of another: LipS1D1-S2D1 (serotypes 1 and 2), Lip-S4D1-S3hybD1 (serotypes 3 and 4), and Lip-S5D1-S6D1 (serotypes 5 and 6). Together, these three proteins are designed to provide immunological coverage across OspA serotypes 1–6, addressing the principal Borrelia genospecies in both North America and Europe. Retrieved Pfizer filings describe an administration regimen requiring at least three doses to elicit a protective immune response in humans.
The chimeric OspA antigen design lineage originates with filings from Baxter International and the Research Foundation for the State University of New York, subsequently assigned to Baxalta Incorporated and Baxter Healthcare S.A. These earlier filings describe chimeric OspA molecules that combine the proximal portion of one OspA serotype with the distal portion of another, retaining the antigenic properties of both parent polypeptides. European epidemiological data cited in these filings indicates that coverage of serotypes 1, 2, 3, 4, 5, and 6 addresses 98.1% of European Lyme disease isolates — the quantitative justification for the hexavalent design target. Multiple Baxter-lineage filings remain active in EP and CA jurisdictions, creating a layered IP structure around VLA15 that any competitor would need to design around.
“Anti-OspA antibodies act in the tick midgut during blood feeding, destroying spirochetes before they enter the mammalian host — a transmission-blocking mechanism confirmed across multiple patent documents spanning three decades of Lyme disease vaccine research.”
Pfizer’s patent estate covers the three-OspA-fusion-protein composition across at least 8 jurisdictions — WO, US, CA, AU, MX, IN, IL, and MX — with filings spanning 2021 to 2025 and the US composition patent attaining active status in 2023. The Medical College of Wisconsin’s 2025 WO filing explicitly states that “Current human Lyme disease vaccine candidate VLA15 from Pfizer and Valneva in Phase 3 trials use a [multivalent OspA approach],” providing the clearest clinical development signal in the retrieved dataset. According to data tracked by organisations such as ClinicalTrials.gov, the Phase 3 programme represents the first human Lyme vaccine trial at this stage since LYMErix was withdrawn from the US market in 2002.
VLA15, co-developed by Pfizer and Valneva, is a three-component lipidated OspA fusion protein vaccine covering serotypes 1–6 of OspA across Borrelia genospecies. It is the only Lyme disease vaccine candidate in Phase 3 clinical trials identified in the patent dataset as of 2025. The administration regimen requires at least three doses.
Explore the full Pfizer VLA15 patent estate and chimeric OspA IP landscape in PatSnap Eureka.
Analyse Lyme Disease Patents in PatSnap Eureka →Sanofi’s mRNA platform and the OspC chimeric alternatives
Sanofi’s mRNA Lyme disease vaccine represents the most technologically novel modality in the retrieved patent dataset and the most significant potential competitive disruption to VLA15. Filed across WO (2023), US (2025), and CN (2024) jurisdictions — with priority claimed to European applications from December 2021 — Sanofi’s platform encodes at least one antigenic polypeptide derived from Borrelia spp. within an mRNA open reading frame, formulated with lipid nanoparticle components including DMG-PEG2000, cholesterol, and DOPE. The key immunogenicity claim is striking: the CN filing explicitly states that in certain embodiments, subjects administered the mRNA Lyme vaccine achieve higher serum anti-OspA antibody concentrations than those receiving a recombinant OspA protein vaccine. Routes of administration described include intramuscular, intranasal, intravenous, subcutaneous, and intradermal delivery. Based on available patent data, this modality appears to be in preclinical or early development, with no explicit clinical trial references in retrieved filings.
Parallel to the mRNA approach, a well-represented patent cluster addresses OspC-based vaccine formulations. OspC is the dominant surface protein expressed during early mammalian infection — a distinct expression window from OspA, which is primarily expressed during tick-stage colonisation. Virginia Commonwealth University (Marconi) has filed on polyvalent chimeric OspC vaccinogens encoding immunodominant epitopes from the loop 5 and alpha helix 5 domains of multiple OspC types, providing broad cross-protection across mammalian Borrelia infections. The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences holds an active EP patent (2017) on combined OspA/OspC chimeric polyepitope recombinant antigens formulated with adjuvants and ferritin II, intended for both human and veterinary use — a combined antigen strategy that is further advanced in the veterinary (canine) setting, as demonstrated by Schering-Plough and Intervet International filings.
Sanofi’s CN patent filing (2024) explicitly claims that in certain embodiments, subjects administered the mRNA Lyme disease vaccine achieve higher serum anti-OspA antibody concentrations than those receiving a recombinant OspA protein vaccine. If substantiated in clinical data, this could establish a second-generation competitive position relative to VLA15.
Vitruviae LLC represents a mechanistically distinct approach entirely: its WO, CA, and US filings describe vaccine compositions comprising synthetic Borrelia glycolipid antigens BBGL-1 and BBGL-2, formulated with adjuvants including beta-glucan. These filings also disclose antibody or antibody fragment compositions binding lipid antigens applicable to diagnosis, monitoring, treatment, and prevention of Lyme disease. This lipid antigen platform targets a class of Borrelia surface molecules distinct from outer surface proteins, potentially complementing protein-based approaches in combination formulations. Guidance from organisations such as EMA on novel antigen combination strategies will be relevant as these approaches advance.
Sanofi has filed an mRNA Lyme disease vaccine platform across WO (2023), US (2025), and CN (2024) jurisdictions, encoding Borrelia-derived antigenic polypeptides in lipid nanoparticle formulations containing DMG-PEG2000, cholesterol, and DOPE. Patent filings claim higher serum anti-OspA antibody concentrations compared to recombinant OspA protein vaccines in certain embodiments. The platform is at preclinical or early development stage based on available patent data.
Post-treatment Lyme disease syndrome: the diagnostic and therapeutic frontier
Post-treatment Lyme disease syndrome (PTLDS) — persistent symptoms following antibiotic treatment where standard diagnostics cannot confirm whether spirochetal infection has been eliminated — represents the most underserved therapeutic and diagnostic market in the Lyme disease IP landscape. Retrieved patent filings reveal two distinct IP clusters addressing this challenge, with limited competition from major pharmaceutical assignees.
Johns Hopkins University has filed patents (WO and US, 2020 and 2022) on diagnostic compositions combining the C6 peptide — an invariable, antigenically conserved VlsE-derived sequence (MKKDDQIAAAIALRGMAKDGKFAVKDGE) present across B. burgdorferi sensu lato strains — with microcolony persister antigens (MPA). MPA are antigens derived from Borrelia biofilm/persister forms, a cell state associated with treatment-refractory infection. Retrieved results indicate that the combined use of MPA and C6 peptide improves sensitivity for PTLDS diagnosis beyond what either marker achieves alone.
QIAGEN Sciences and Biopeptides Corp. hold active EP and MX patents (2018, 2022) on a complementary approach: T-cell interferon-γ assay platforms using synthetic peptides encompassing T-cell epitope-containing regions of stage-specific Borrelia proteins to detect immune responses in whole blood. These assays are designed to predict whether antibiotic treatment has eliminated spirochetal infection — addressing the clinical problem of PTLDS where persistent symptoms after treatment remain diagnostically ambiguous. Caprion Proteomics Inc. adds a third layer with proteomic biomarker signatures (ICAM1, LYN, MMP9, and HIST4H4) for discriminating Lyme disease from Brucellosis and Q-Fever and for monitoring treatment effectiveness, with active/inactive IP across WO, CA, EP, AU, NZ, and HK jurisdictions.
Johns Hopkins University patent filings describe diagnostic compositions combining the C6 peptide (VlsE-derived sequence MKKDDQIAAAIALRGMAKDGKFAVKDGE) with microcolony persister antigens (MPA) derived from Borrelia biofilm/persister forms. The combined use of MPA and C6 peptide improves sensitivity for post-treatment Lyme disease syndrome (PTLDS) diagnosis compared to either marker alone.
The Medical College of Wisconsin’s 2025 WO filing (eabfcf16) signals an emerging direction toward T-cell–mediated immunity as a vaccination strategy, disclosing conjugate vaccine polypeptide compositions that attempt to combine humoral and cellular immune targets — a departure from the antibody-centric OspA approach that has dominated the field. Research published through institutions tracked by NIH has increasingly recognised the role of cellular immunity in Lyme disease pathogenesis, lending biological plausibility to this direction.
Track PTLDS diagnostic IP from Johns Hopkins, QIAGEN Sciences, and Caprion Proteomics in real time.
Explore PTLDS Patent Intelligence in PatSnap Eureka →IP landscape: assignees, jurisdictions, and competitive positioning
The Lyme disease vaccine IP landscape is characterised by a dominant commercial cluster around VLA15 and a fragmented academic/emerging-company layer covering alternative modalities. Pfizer is the most prolific current assignee in this dataset, with at least 8 distinct patent records across WO, US, CA, AU, MX, IN, IL, and MX jurisdictions — all directed to the three OspA fusion protein composition. Sanofi holds the principal mRNA platform IP. The Baxter International / Baxalta / Baxter Healthcare lineage underpins the chimeric OspA antigen design with active EP and CA filings, creating layered IP around VLA15 that any new entrant would need to navigate.
Academic institutions contribute significant secondary IP. Virginia Commonwealth University holds active and inactive IP on polyvalent chimeric OspC vaccinogens. The Czech Academy of Sciences holds an active EP patent on combined OspA/OspC chimeric polyepitope vaccines. The Research Foundation for the State University of New York holds active OspA chimera IP in CA, with overlapping inventorship with the Baxter lineage. Antigen Discovery Inc. holds a WO filing (2023) and a pending US application (2026) on novel antigens for early detection of B. afzelii-caused Lyme disease — a genospecies responsible for approximately 80% of European Lyme infections per retrieved filings.
Baxter International’s Chinese patents explicitly describe combination vaccines incorporating chimeric OspA antigens alongside antigens for other tick-borne diseases including Rocky Mountain spotted fever, babesiosis, tick-borne encephalitis, Powassan encephalitis, and ehrlichiosis. This signals a potential tick-borne disease combination vaccine strategy that, given the expanding geographic range of tick populations linked to climate change (referenced in Antigen Discovery filings), could be both commercially and epidemiologically compelling. Regulatory frameworks from bodies such as FDA for combination vaccine licensing will be a critical consideration for this strategy.
Post-treatment Lyme disease syndrome diagnostics and treatment monitoring represent an underserved market with limited competition from major pharmaceutical assignees. Johns Hopkins University (MPA antigens) and QIAGEN Sciences (T-cell interferon-γ assays) hold the most specific IP in this space. Drug developers targeting persistent post-infection disease face a relatively open competitive landscape based on this dataset.
The overall IP architecture can be summarised as follows: a single Phase 3 candidate (VLA15) with broad multi-jurisdictional protection; a potential second-generation mRNA disruptor (Sanofi) still in early development; a cluster of preclinical differentiation strategies (OspC chimeras, lipid antigens, T-cell epitopes, combination tick-borne vaccines); and an emerging PTLDS diagnostic/monitoring segment with academic IP available for licensing. For IP strategists evaluating entry into the Lyme vaccine space, the Sanofi mRNA platform prosecution in US and CN jurisdictions (2024–2025) warrants close monitoring, as pending claims may establish blocking positions if immunogenicity advantages are substantiated clinically. PatSnap’s patent analytics platform provides the landscape mapping tools needed to track these prosecution trajectories in real time.