Executive summary
United States Patent 10,336,793 claims a vaccination method using a flagellin-based adjuvant (sequence identity to SEQ ID NO: 2 of ≥95%) combined with an aluminum gel or salt (e.g., aluminum hydroxide/phosphate/sulfate) at very low flagellin:aluminum w/w ratios ≤ about 1:500, with an antigen that is a constituent of live-attenuated, killed/inactivated, or toxoid infectious agents. The claims are broad on target disorders (infectious diseases, cancers, allergies), but materially constrained by the adjuvant architecture (specific flagellin sequence plus aluminum at a defined low loading range) and by alleged functional effects (notably abrogation of neutralizing anti-flagellin antibodies).
Critical licensing and litigation risk for competitors is concentrated in (i) flagellin-alum combinations at substantially below aluminum loading capacity, (ii) SEQ ID NO: 2 identity-level flagellin variants, (iii) adsorption/stable-complex formulations on aluminum salts, and (iv) asserted performance against anti-flagellin neutralization. The enforceable estate is strongest where a generic or biosimilar-like vaccine entrant copies the same adjuvant quantitative regime and same flagellin sequence scope, rather than merely using flagellin and alum separately.
What is US Patent 10,336,793 and what do claims 1–15 actually cover?
Core claim concept (claim 1)
A method of vaccinating a subject against a disorder by administering a vaccine comprising:
- Adjuvant package
- A flagellin-based agent with an amino acid sequence having ≥95% identity with SEQ ID NO: 2, plus
- An aluminum gel or salt (the spec supports typical aluminum salts; dependent claims list hydroxide, phosphate, sulfate), where
- The w/w ratio of flagellin-based agent to aluminum gel or salt is about 1:500 or less.
- Antigen package
- An antigen that stimulates protective immunity against the disorder, where the antigen is a constituent of an infectious agent selected from live and attenuated, killed, inactivated, and toxoid infectious agents.
- Disorder scope
- Disorder is selected from infectious diseases, cancers, and allergies.
Claim-by-claim expansion (claims 2–15)
- Claim 2: Enumerates specific infectious disorders (diphtheria, tetanus, pertussis, influenza, pneumonia, hepatitis A/B, polio, yellow fever, HPV, anthrax, rabies, Japanese encephalitis, meningitis, measles, mumps, rubella, gastroenteritis, smallpox, typhoid, varicella, rotavirus, shingles).
- Claim 3: Limits flagellin-based agent to having the amino sequence of SEQ ID NO: 2 (tightest sequence boundary).
- Claim 4: Adds a functional limitation: the flagellin inhibits and abrogates neutralizing anti-flagellin antibodies from neutralizing the adjuvant.
- Claim 5: Limits aluminum to aluminum hydroxide, phosphate, or sulfate.
- Claims 6–8: Cover formulation handling on alum:
- antigen and/or flagellin adsorbed to aluminum gel/salt,
- formation of a stable complex by mixing,
- mixing at ratios substantially below aluminum’s loading capacity.
- Claim 9: Provides a ratio ladder for alleged infringing compositions: about 1:500, 1:600, 1:700, 1:800, 1:900, 1:1000, 1:2000, 1:5000, 1:10000.
- Claim 10: Enumerates antigen/vaccine exemplars (DTP/DTaP, Hib conjugates, pneumococcal conjugate, Hep A/B, poliomyelitis, yellow fever, HPV, anthrax, rabies).
- Claim 11: Adds optional further adjuvants (oil-in-water emulsion, saponin, ovalbumin, Freund’s adjuvant, cytokines, chitosans).
- Claim 12: Adds immunological response framing: vaccine causes immunostimulation of T_H1 and T_H2-mediated response.
- Claim 13: Route: oral or parenteral injection.
- Claim 14: Delivery: controlled-release/sustained-release.
- Claim 15: Dosing strategy: once or booster.
What is most “claim-defining”
For infringement screening, the key differentiators are:
- Flagellin sequence constraint: ≥95% identity to SEQ ID NO: 2, and in some claims exactly SEQ ID NO: 2.
- Quantitative adjuvant ratio: flagellin to alum ≤ 1:500, with explicit alternative ratios down to 1:10000.
- Physical integration: adsorption and stable complex on alum.
- Functional anti-neutralization feature: abrogation of neutralizing anti-flagellin antibodies.
- Antigen provenance constraint: antigen is constituent of live attenuated, killed/inactivated, toxoid infectious agents.
Which antigens and disorders are covered, and how broad is the subject-matter?
Broad “disorder” category, narrow “antigen provenance”
Claim 1’s disorder field is wide (infectious diseases, cancers, allergies). However, claim 1 ties antigen to infectious-agent categories: live/attenuated, killed/inactivated, or toxoid. That means cancer/allergy coverage likely depends on whether the relevant antigen qualifies as a “constituent” of one of those infectious-agent types. In practice, this is an interpretive pressure point for enforcement: a defendant can argue cancer/allergy embodiments do not meet the defined antigen provenance.
Enumerated lists increase clarity for enforcement
Claims 2 and 10 list many specific infectious targets and representative vaccine families. If a competitor’s product is one of these, the remaining disputed elements are likely to narrow to the adjuvant package: flagellin sequence, alum salt identity, ratio, and the claimed adsorption/complex formation.
What patents protect flagellin-alum vaccine formulations after US 10,336,793?
Claim-scope map to common patent “clusters”
Even without reproducing a full family map, the claim language indicates the relevant IP clusters that tend to recur across flagellin-alum patents:
- Flagellin sequence variants (identity to a specific SEQ ID NO., truncations, chimeras).
- Flagellin-aluminum salt combinations (adsorption, co-formulation, stable complex claims).
- Quantitative loading/ratio regimes (low flagellin dose relative to alum; “below loading capacity”).
- Anti-flagellin antibody neutralization mitigation (functional effect limitations).
- Antigen-type limitations (live attenuated, killed/inactivated, toxoid antigen provenance).
Practical take
If a competitor’s formulation uses a different flagellin (sequence not meeting ≥95% to SEQ ID NO: 2, or a different motif outside the defined region), or if it uses alum but at a higher flagellin:aluminum ratio than the ≤1:500 regime, patent risk drops sharply. If it matches the exact quantitative regime and sequence boundary, risk increases regardless of the particular infectious antigen, because the antigen is largely “constituent-of” rather than tied to a single pathogen in claim 1.
How strong is the patent estate for the adjuvant ratio and SEQ ID NO: 2 identity limits?
1) Sequence identity: ≥95% identity to SEQ ID NO: 2
This is a meaningful narrowing compared with patents that claim “any flagellin.” It still provides room for engineered variants, but it creates a measurable infringement test: align the amino acid sequences and evaluate percent identity. Claim 3 and the “SEQ ID NO: 2” limitation tighten enforceability further for exact-match products.
2) Ratio constraint: ≤ 1:500 and the explicit “ratio ladder”
Claim 1 and 9 place quantitative bounds on infringement analysis. Competitors can attempt “design-around” by increasing the flagellin dose relative to alum so that the ratio exceeds the permitted threshold. However, claim 8’s “substantially below loading capacity” can complicate purely numerical arguments if it is interpreted as a functional formulation characteristic.
3) Aluminum salt identity (dependent claim)
Claim 5 narrows to aluminum hydroxide, phosphate, or sulfate. If a competitor uses another aluminum adjuvant (or another salt form not captured), claim 5 may be avoided, but claim 1 still requires “aluminum gel or salt,” so avoidance depends on whether the alternative is still considered within the covered concept.
4) Functional limitation: neutralizing anti-flagellin antibodies abrogation
Claim 4 creates an additional hurdle for both enforcement and validity, since functional limitations often raise questions about proof, enablement, and whether the effect is inherent to the claimed composition. For a plaintiff, it is also a powerful differentiator if experimental data show the specific formulation neutralizes anti-flagellin antibody activity.
When does US 10,336,793 lose exclusivity, and what is the likely enforceability window?
A precise exclusivity timeline and expiration date requires the patent’s filing date, priority data, and term adjustments. Those are not provided in the prompt, and the only input is the claim set. Without filing and priority facts, any “expiration date” would be speculative and cannot be treated as a reliable business timeline.
What Paragraph IV and generic entry risks exist for vaccines vs. drugs?
Vaccines are typically not “generic” under the Hatch-Waxman framework in the same way as small molecules, and the relevant litigation trigger is often a combination of:
- state and federal patent infringement suits, and
- FDA pathway and data exclusivity interactions.
Within that context, US 10,336,793 frames risk in terms of formulation copying rather than “bioequivalence” to an active ingredient. A competitor’s entry risk hinges on whether their vaccine uses:
- a flagellin-based agent meeting the SEQ ID NO: 2 identity definition, and
- alum at a flagellin:aluminum ratio ≤ 1:500 (or the enumerated equivalents), and
- antigen and adjuvant handled via adsorption/stable complex approaches, and
- (for claim 4) an ability to abrogate neutralizing anti-flagellin antibodies.
How do claims on adsorption/stable complex change infringement analysis for vaccine manufacturers?
Adsorbed to aluminum gel or salt (claim 6)
This can be a decisive factual issue. Many vaccine manufacturing processes involve mixing steps that may cause physical association, but “adsorbed” can be construed as a specific interaction. A defendant may argue their product is merely blended without adsorption, or that the flagellin is not bound under the conditions used to measure adsorption.
Stable complex (claim 7)
“Stable” invites disputes over stability characterization. It can also be a manufacturing control variable. If a competitor forms a different colloidal association on alum that is not “stable complex” as understood by the patent, it may avoid this element.
“Substantially below loading capacity” (claim 8)
This invites interpretive and experimental disputes. It is more ambiguous than an exact ratio, but claim 9 provides exact ratios in dependent form. Products that do not meet the ratio thresholds are better positioned against claim 8.
How does US 10,336,793 compare with other flagellin adjuvant patents focused on TLR5?
Functional targeting of the immune response
The claim set does not require TLR5 explicitly, but flagellin-based adjuvants generally activate innate immunity pathways associated with flagellin. The distinguishing elements here are:
- aluminum co-adjuvant at strict low ratios, and
- sequence identity to a specific SEQ ID NO: 2, and
- neutralizing anti-flagellin antibody abrogation.
Other flagellin patents may claim general flagellin-based adjuvant methods, different salts (non-aluminum), or higher loading regimes. The quantitative alum constraint is the primary differentiator for a competitor’s design-around plan.
What formulation and manufacturing design-around strategies are most credible?
Most credible design-around levers in claim language
- Change flagellin sequence outside ≥95% identity scope (avoid SEQ ID NO: 2 and any close homologs).
- Increase flagellin:aluminum ratio above 1:500 (and above the enumerated alternatives) to exit claim 1/9’s quantitative boundaries.
- Avoid adsorption/stable complex claims via distinct physical formulation design, with process documentation showing lack of adsorption or different complex formation.
- Do not rely on anti-flagellin antibody abrogation as a functional property (or demonstrate the product does not provide it), relevant especially for claim 4.
- Aluminum salt selection: use an aluminum form argued not to fall within “gel or salt” as construed or not within hydroxide/phosphate/sulfate if claim 5 is pursued by a court.
Key litigation touchpoints implied by the claim set
Even without docket data in the prompt, the claim language indicates typical litigation battlegrounds:
- Sequence identity evidence (protein sequence alignment and expert testimony).
- Adjuvant ratio measurement (batch testing, acceptance specs, QA/QC records).
- Adsorption/complex formation (analytical chemistry and formulation stability characterization).
- Functional antibody abrogation (immunology assays and whether they are reproducible across lots).
- Antigen provenance (whether antigens used in “live/killed/toxoid” categories satisfy “constituent of an infectious agent” requirement, especially for nontraditional targets like cancer/allergy).
What is the Orange Book status of US 10,336,793?
US patents on vaccines do not map cleanly to the FDA Orange Book, which primarily lists drug products approved under the Biologics Price Competition and generic “drug” frameworks. Determining Orange Book listing requires product identifiers and the patent’s FDA-listed connections, which are not included in the prompt. Therefore, an Orange Book status statement cannot be produced from the provided data.
Commercial exposure: which vaccine programs are most exposed to infringement of this claim set?
Exposure concentrates on products that copy the adjuvant architecture
Commercial exposure is highest for next-generation or platform vaccines that:
- use flagellin as an adjuvant,
- co-formulate with aluminum salts, and
- do so with very low flagellin dose relative to alum (≤1:500) and likely adsorb or complex the components on alum.
Among the claim’s enumerated targets, exposure also increases if an in-market or late-stage vaccine targets DTP/DTaP, Hib conjugates, pneumococcal conjugates, Hep A/B, polio, yellow fever, HPV, anthrax, or rabies, because the antigen/vaccine lists appear designed for easier fit-to-product mapping.
Key Takeaways
- US 10,336,793 is an enforceability-sensitive formulation and method patent focused on a flagellin-aluminum adjuvant with a tight sequence definition (≥95% identity to SEQ ID NO: 2) and a quantitative ratio (flagellin:aluminum ≤1:500).
- Dependent claims add practical manufacturing hooks: adsorption, stable complex, and below alum loading capacity.
- The strongest infringement profile occurs when a competitor’s vaccine matches the exact or near-exact sequence boundary and uses alum at a low-flagellin regime plus comparable adjuvant integration methods.
- The most credible design-arounds are: sequence divergence, ratio increase above 1:500, and avoiding adsorption/stable complex behavior.
- Without filing/priority metadata, the expiration timeline and any Orange Book status cannot be determined from the provided prompt.
FAQs
1) Do claim 1 and claim 9 require the same exact w/w ratio?
Claim 1 requires about 1:500 or less; claim 9 lists additional about ratios (down to about 1:10000). A product meeting any of the claim 9 enumerated ratios may still fall within claim 1’s general threshold if it remains ≤1:500.
2) Is the antigen restricted to specific pathogens or specific antigen types?
Claim 1 restricts antigens to those that are constituents of infectious agents that are live/attenuated, killed/inactivated, or toxoid. Claims 2 and 10 then identify pathogen and vaccine exemplars.
3) Can a competitor use a different aluminum salt to avoid claim 5?
Claim 5 narrows aluminum to hydroxide/phosphate/sulfate, but claim 1 still requires an “aluminum gel or salt.” Avoidance depends on claim construction of “aluminum gel or salt” and whether the alternative is included.
4) How does claim 4’s anti-flagellin antibody abrogation affect proof in litigation?
Claim 4 adds an immunological functional limitation, which typically requires comparative immunology assays and lot-to-lot evidence that the adjuvant inhibits neutralization by anti-flagellin antibodies.
5) Is oral delivery covered even if the patent was designed for injections?
Yes. Claim 13 expressly includes oral or parenteral injection, and claim 14 covers controlled-release/sustained-release.
References (APA)
- United States Patent 10,336,793, “Method of vaccinating a subject,” claims 1–15 (as provided in prompt).
