diff --git a/src/lib/vaccinations/__tests__/catalog-integrity.test.ts b/src/lib/vaccinations/__tests__/catalog-integrity.test.ts
new file mode 100644
index 000000000..5dc9dfe88
--- /dev/null
+++ b/src/lib/vaccinations/__tests__/catalog-integrity.test.ts
@@ -0,0 +1,209 @@
+/**
+ * What the catalogue promises about itself, and the one promise it makes to
+ * every row that outlives it.
+ *
+ * The structural checks below are cheap and mostly hold shapes the type system
+ * already holds — they exist because the file is edited by hand, entry by
+ * entry, and a paste that duplicates a slug or points a combination at an
+ * antigen that no longer exists compiles fine right up until two doses share
+ * an identity.
+ *
+ * The one that matters is the last block: a slug this release does not know
+ * must degrade to the record's own free text. A record keeps `antigenSlug`
+ * verbatim, backups restore it without validation, and slugs are append-only
+ * by convention rather than by constraint — so the day one is dropped or
+ * renamed, every dose that carried it is still a real dose belonging to a real
+ * person. The resolver returning `null` is what makes that survivable, and a
+ * resolver that threw or a renderer that produced an empty label would turn a
+ * catalogue edit into data loss on screen.
+ */
+import { describe, expect, it } from "vitest";
+
+import {
+  ANTIGEN_SLUGS,
+  VACCINE_CATALOG,
+  VACCINE_CATALOG_SLUGS,
+  componentsForSlug,
+  resolveCatalogEntry,
+  type AntigenSlug,
+} from "@/lib/vaccinations/vaccine-catalog";
+
+const MONOVALENT = new Set<string>(ANTIGEN_SLUGS);
+
+describe("the vaccine catalogue holds its own shape", () => {
+  it("carries a whole life's worth of entries, not a token list", () => {
+    // The floor is not decoration: an adult-only catalogue was the rejected
+    // alternative, and it would ship a module that cannot hold a child's
+    // Pass. A count that collapses is the symptom.
+    expect(VACCINE_CATALOG.length).toBeGreaterThanOrEqual(30);
+    expect(MONOVALENT.size).toBeGreaterThanOrEqual(20);
+  });
+
+  it("gives every entry a unique slug", () => {
+    const seen = new Map<string, number>();
+    for (const slug of VACCINE_CATALOG_SLUGS) {
+      seen.set(slug, (seen.get(slug) ?? 0) + 1);
+    }
+    const duplicated = [...seen.entries()]
+      .filter(([, count]) => count > 1)
+      .map(([slug]) => slug);
+    expect(
+      duplicated,
+      "two entries under one slug means two doses share an identity",
+    ).toEqual([]);
+  });
+
+  it("offers every monovalent antigen as an entry of its own", () => {
+    // An older Pass line records a component on its own, so every antigen a
+    // combination can contain must also be loggable by itself.
+    const missing = ANTIGEN_SLUGS.filter(
+      (slug) => !VACCINE_CATALOG_SLUGS.includes(slug),
+    );
+    expect(missing).toEqual([]);
+  });
+
+  it("resolves every combination's components to real monovalent antigens", () => {
+    const foreign: string[] = [];
+    for (const entry of VACCINE_CATALOG) {
+      for (const component of entry.components) {
+        if (!MONOVALENT.has(component))
+          foreign.push(`${entry.slug}/${component}`);
+      }
+    }
+    expect(
+      foreign,
+      "a component that is not an antigen breaks the series axis silently",
+    ).toEqual([]);
+  });
+
+  it("makes every monovalent entry its own single component", () => {
+    const wrong = VACCINE_CATALOG.filter(
+      (entry) =>
+        MONOVALENT.has(entry.slug) &&
+        (entry.components.length !== 1 || entry.components[0] !== entry.slug),
+    ).map((entry) => entry.slug);
+    expect(
+      wrong,
+      "a monovalent that does not count into its own series counts into none",
+    ).toEqual([]);
+  });
+
+  it("gives every entry an ATC code in the J07 subtree", () => {
+    const wrong = VACCINE_CATALOG.filter(
+      (entry) => !/^J07[A-Z]{2}\d{2}$/.test(entry.atc),
+    ).map((entry) => `${entry.slug}: ${entry.atc}`);
+    expect(wrong).toEqual([]);
+  });
+
+  it("cites a source for every entry's numbers", () => {
+    // Rendered numbers need a rendered citation. A blank or one-word source
+    // is how a footnote stops being checkable.
+    const thin = VACCINE_CATALOG.filter(
+      (entry) => entry.source.trim().length < 8,
+    ).map((entry) => entry.slug);
+    expect(thin).toEqual([]);
+  });
+
+  it("keeps the numbers inside the range a schedule can mean", () => {
+    const wrong: string[] = [];
+    for (const entry of VACCINE_CATALOG) {
+      const { typicalSeriesDoses: doses, boosterIntervalMonths: months } =
+        entry;
+      if (doses !== null && (doses < 1 || doses > 10)) {
+        wrong.push(`${entry.slug}: ${doses} doses`);
+      }
+      if (months !== null && (months < 1 || months > 240)) {
+        wrong.push(`${entry.slug}: every ${months} months`);
+      }
+    }
+    expect(wrong).toEqual([]);
+  });
+
+  it("keeps every synonym generic, lowercase and distinct", () => {
+    // The vendor-name rule cannot be fully held by a matcher — a trade name
+    // is a proper noun and nothing here knows the register. What a test CAN
+    // hold is the shape a trade name would have to break: synonyms are
+    // lowercase generic wording, never blank, never repeated.
+    const wrong: string[] = [];
+    const seen = new Set<string>();
+    for (const entry of VACCINE_CATALOG) {
+      for (const synonym of entry.synonyms ?? []) {
+        if (synonym !== synonym.toLowerCase() || synonym.trim().length === 0) {
+          wrong.push(`${entry.slug}: ${synonym}`);
+        }
+        if (seen.has(synonym)) wrong.push(`${entry.slug}: repeats ${synonym}`);
+        seen.add(synonym);
+      }
+    }
+    expect(wrong).toEqual([]);
+  });
+});
+
+describe("a slug the catalogue no longer knows degrades to the free text", () => {
+  /**
+   * A record as the app would hold it after the catalogue moved on: a slug
+   * written by an older release, and the person's own transcription beside it.
+   */
+  const ORPHANED_RECORD = {
+    antigenSlug: "an-antigen-this-release-does-not-list",
+    vaccineName: "Tetanus, as the 1987 Pass wrote it",
+  };
+
+  /**
+   * What every consumer of the catalogue does with a record: ask the resolver,
+   * take the catalogue's name when it answers, fall back to the person's own
+   * wording when it does not. Written here rather than imported so the
+   * guarantee is checked as a contract on the resolver, which is what every
+   * caller depends on.
+   */
+  function displayIdentity(record: {
+    antigenSlug: string | null;
+    vaccineName: string | null;
+  }): string {
+    const entry = resolveCatalogEntry(record.antigenSlug);
+    return entry ? entry.slug : (record.vaccineName ?? "");
+  }
+
+  it("returns null instead of throwing for a slug it does not have", () => {
+    expect(() =>
+      resolveCatalogEntry(ORPHANED_RECORD.antigenSlug),
+    ).not.toThrow();
+    expect(resolveCatalogEntry(ORPHANED_RECORD.antigenSlug)).toBeNull();
+  });
+
+  it("renders the person's own wording rather than an empty label", () => {
+    const label = displayIdentity(ORPHANED_RECORD);
+    expect(
+      label,
+      "an unresolvable slug must degrade to the free-text arm; an empty " +
+        "label turns a catalogue edit into data loss on screen",
+    ).toBe("Tetanus, as the 1987 Pass wrote it");
+    expect(label.length).toBeGreaterThan(0);
+  });
+
+  it("degrades the same way for a null slug and an empty one", () => {
+    expect(resolveCatalogEntry(null)).toBeNull();
+    expect(resolveCatalogEntry(undefined)).toBeNull();
+    expect(resolveCatalogEntry("")).toBeNull();
+    expect(
+      displayIdentity({ antigenSlug: null, vaccineName: "Free text only" }),
+    ).toBe("Free text only");
+  });
+
+  it("matches no antigen at all rather than guessing from the name", () => {
+    // The consequence that matters: an unresolvable dose must not clear a
+    // booster reminder. No components means no match.
+    expect(componentsForSlug(ORPHANED_RECORD.antigenSlug)).toEqual([]);
+    expect(componentsForSlug(null)).toEqual([]);
+  });
+
+  it("still resolves a slug it does have, so the check above is not vacuous", () => {
+    const tdap = resolveCatalogEntry("tdap");
+    expect(tdap).not.toBeNull();
+    expect(tdap?.components).toEqual<AntigenSlug[]>([
+      "tetanus",
+      "diphtheria",
+      "pertussis",
+    ]);
+  });
+});
diff --git a/src/lib/vaccinations/vaccine-catalog.ts b/src/lib/vaccinations/vaccine-catalog.ts
new file mode 100644
index 000000000..d10022d53
--- /dev/null
+++ b/src/lib/vaccinations/vaccine-catalog.ts
@@ -0,0 +1,559 @@
+/**
+ * The antigen-level vaccine catalogue: what a dose can be, in one static list.
+ *
+ * This is NOT a DB table, for the same reason `BIOMARKER_CATALOG` is not one
+ * (`src/lib/labs/biomarker-catalog.ts`): the slug is the stable identity, the
+ * display name resolves through i18n, the numbers are correctable in a patch
+ * release rather than a migration, and an account that has never opened the
+ * picker carries no rows for it.
+ *
+ * ── What it deliberately is not ────────────────────────────────────────────
+ *
+ * There is no manufacturer column and there is no trade name anywhere in it.
+ * Entries are named for the antigen or the disease, synonyms are generic or
+ * colloquial, and the one place a trade name may legitimately appear in this
+ * feature is the user's own `vaccineName` transcription of their Pass — their
+ * data, not our content.
+ *
+ * The numbers are TYPICAL values for orientation, and `source` names where
+ * each one comes from so the sentence rendered beside a dose carries its
+ * citation. They are not an individual schedule: what a particular person
+ * needs and when depends on their history, their age and their reasons, and
+ * that adjudication belongs to their doctor. Nothing in this file or in
+ * anything reading it computes what is due — the module renders what a person
+ * logged and, at most, offers to set a reminder they confirm themselves.
+ *
+ * ── Slugs are append-only ──────────────────────────────────────────────────
+ *
+ * A record stores `antigenSlug` verbatim, backups restore it without
+ * validation, and a slug this file has stopped listing must still describe
+ * what someone was given. {@link resolveCatalogEntry} is the ONLY lookup path
+ * and it returns `null` rather than throwing; every consumer answers `null` by
+ * falling back to the record's own `vaccineName`. That degrade is a tested
+ * guarantee, not an accident — see
+ * `src/lib/vaccinations/__tests__/catalog-integrity.test.ts`.
+ *
+ * ── Combinations ───────────────────────────────────────────────────────────
+ *
+ * `components` is the axis everything downstream turns on. A combination lists
+ * the monovalent antigens it contains, so one Tdap dose counts into the
+ * tetanus, the diphtheria AND the pertussis series, and clears a booster
+ * reminder for any of them. A monovalent lists itself.
+ *
+ * ATC codes are the WHO J07 subtree at the most specific level that stays
+ * product-blind. Two entries may legitimately share a code: ATC classifies by
+ * antigen combination and does not distinguish a full-strength childhood
+ * preparation from the reduced-antigen adult one.
+ */
+
+/** The monovalent antigens a dose can contain. Combinations reference these. */
+export const ANTIGEN_SLUGS = [
+  "tetanus",
+  "diphtheria",
+  "pertussis",
+  "polio",
+  "measles",
+  "mumps",
+  "rubella",
+  "varicella",
+  "hib",
+  "hepatitis-a",
+  "hepatitis-b",
+  "influenza",
+  "pneumococcal",
+  "herpes-zoster",
+  "rsv",
+  "covid-19",
+  "fsme",
+  "hpv",
+  "meningococcal-acwy",
+  "meningococcal-b",
+  "rotavirus",
+  "typhoid",
+  "rabies",
+  "yellow-fever",
+  "japanese-encephalitis",
+  "cholera",
+] as const;
+
+export type AntigenSlug = (typeof ANTIGEN_SLUGS)[number];
+
+/**
+ * How the picker groups an entry.
+ *
+ * `standard` is the general schedule, `standard60` the additions recommended
+ * from the later decades, `childhood` what a child's Pass fills up with,
+ * `indication` what a particular exposure or condition calls for, and `travel`
+ * what a destination does. A person's own Pass mixes all five, which is why
+ * the catalogue covers a whole life rather than an adult floor.
+ */
+export type VaccineCategory =
+  "standard" | "standard60" | "childhood" | "indication" | "travel";
+
+export interface VaccineSeed {
+  /** Stable EN identity; `vaccinations.catalog.<slug>` resolves the name. */
+  slug: string;
+  /** WHO ATC code (J07 subtree), most specific level that stays product-blind. */
+  atc: string;
+  /** Component antigens — self for monovalents. The series-derivation axis. */
+  components: readonly AntigenSlug[];
+  /** Typical primary-series length, or null (seasonal / single-dose). */
+  typicalSeriesDoses: number | null;
+  /** Typical booster interval in months, or null. 12 = yearly / seasonal. */
+  boosterIntervalMonths: number | null;
+  /** Picker grouping. */
+  category: VaccineCategory;
+  /**
+   * The document the numbers on this entry come from, rendered as the
+   * footnote beside them. A citation is a proper noun, like a unit: literal,
+   * not translated.
+   */
+  source: string;
+  /** Generic search aliases only — never trade names. */
+  synonyms?: readonly string[];
+}
+
+/** The German standing-committee schedule, for everything on it. */
+const STIKO = "STIKO Epid Bull 4/2026";
+
+export const VACCINE_CATALOG: readonly VaccineSeed[] = [
+  // ── Monovalent: the general schedule ────────────────────────────────────
+  {
+    // Primary series in infancy, then a lifelong ten-year rhythm. The
+    // ten-year figure is the one number in this file most people already
+    // know, and the one a reminder is most often set from.
+    slug: "tetanus",
+    atc: "J07AM01",
+    components: ["tetanus"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: 120,
+    category: "standard",
+    source: STIKO,
+    synonyms: ["lockjaw"],
+  },
+  {
+    // Travels with tetanus in practice; the schedule and the interval match,
+    // which is why the combined preparation is the usual one.
+    slug: "diphtheria",
+    atc: "J07AF01",
+    components: ["diphtheria"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: 120,
+    category: "standard",
+    source: STIKO,
+  },
+  {
+    // No fixed adult rhythm: refreshed once in adulthood, and again in each
+    // pregnancy, neither of which is an interval. Null rather than a number
+    // invented to fill the field.
+    slug: "pertussis",
+    atc: "J07AJ02",
+    components: ["pertussis"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: null,
+    category: "standard",
+    source: STIKO,
+    synonyms: ["whooping cough"],
+  },
+  {
+    // Four doses in childhood, one refresher in adolescence. Adults refresh
+    // only for travel to a region where it still circulates, which is a
+    // destination question rather than an interval.
+    slug: "polio",
+    atc: "J07BF03",
+    components: ["polio"],
+    typicalSeriesDoses: 4,
+    boosterIntervalMonths: null,
+    category: "standard",
+    source: STIKO,
+    synonyms: ["poliomyelitis", "ipv"],
+  },
+  {
+    // Three doses in infancy; no routine adult booster.
+    slug: "hepatitis-b",
+    atc: "J07BC01",
+    components: ["hepatitis-b"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: null,
+    category: "standard",
+    source: STIKO,
+    synonyms: ["hep b"],
+  },
+  {
+    // Two doses, then variant-adapted refreshers whose cadence is a moving
+    // recommendation rather than a fixed schedule. Twelve months is the
+    // rhythm the seasonal refresher has settled into.
+    slug: "covid-19",
+    atc: "J07BN01",
+    components: ["covid-19"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: 12,
+    category: "standard",
+    source: STIKO,
+    synonyms: ["coronavirus", "sars-cov-2"],
+  },
+
+  // ── Monovalent: added in the later decades ──────────────────────────────
+  {
+    // Seasonal: one dose per year, and the series concept does not apply.
+    slug: "influenza",
+    atc: "J07BB02",
+    components: ["influenza"],
+    typicalSeriesDoses: 1,
+    boosterIntervalMonths: 12,
+    category: "standard60",
+    source: STIKO,
+    synonyms: ["flu", "seasonal flu"],
+  },
+  {
+    slug: "pneumococcal",
+    atc: "J07AL02",
+    components: ["pneumococcal"],
+    typicalSeriesDoses: 1,
+    boosterIntervalMonths: null,
+    category: "standard60",
+    source: STIKO,
+    synonyms: ["pneumonia"],
+  },
+  {
+    // Two doses, two to six months apart; no booster after them.
+    slug: "herpes-zoster",
+    atc: "J07BK03",
+    components: ["herpes-zoster"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "standard60",
+    source: STIKO,
+    synonyms: ["shingles", "zoster"],
+  },
+  {
+    slug: "rsv",
+    atc: "J07BX05",
+    components: ["rsv"],
+    typicalSeriesDoses: 1,
+    boosterIntervalMonths: null,
+    category: "standard60",
+    source: STIKO,
+    synonyms: ["respiratory syncytial virus"],
+  },
+
+  // ── Monovalent: the childhood Pass ──────────────────────────────────────
+  {
+    // Given as part of a combined preparation in practice; the monovalent
+    // entry exists because an older Pass line may record it on its own.
+    slug: "measles",
+    atc: "J07BD01",
+    components: ["measles"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+  },
+  {
+    slug: "mumps",
+    atc: "J07BE01",
+    components: ["mumps"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+  },
+  {
+    slug: "rubella",
+    atc: "J07BJ01",
+    components: ["rubella"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+    synonyms: ["german measles"],
+  },
+  {
+    slug: "varicella",
+    atc: "J07BK01",
+    components: ["varicella"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+    synonyms: ["chickenpox"],
+  },
+  {
+    slug: "hib",
+    atc: "J07AG01",
+    components: ["hib"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+    synonyms: ["haemophilus influenzae type b"],
+  },
+  {
+    // Oral, and the series is finished early — the whole course sits inside
+    // the first months of life.
+    slug: "rotavirus",
+    atc: "J07BH01",
+    components: ["rotavirus"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+  },
+  {
+    // Two doses when the course starts before fifteen, three when it starts
+    // later. Two is the typical value; the record's own `seriesDoses`
+    // override is there for the person whose Pass says three.
+    slug: "hpv",
+    atc: "J07BM03",
+    components: ["hpv"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+    synonyms: ["human papillomavirus"],
+  },
+
+  // ── Monovalent: by indication ───────────────────────────────────────────
+  {
+    // Three doses, then a refresher every three to five years while the
+    // exposure lasts. Sixty months is the longer end of that window.
+    slug: "fsme",
+    atc: "J07BA02",
+    components: ["fsme"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: 60,
+    category: "indication",
+    source: STIKO,
+    synonyms: ["tick-borne encephalitis", "tbe"],
+  },
+  {
+    slug: "hepatitis-a",
+    atc: "J07BC02",
+    components: ["hepatitis-a"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "indication",
+    source: STIKO,
+    synonyms: ["hep a"],
+  },
+  {
+    slug: "meningococcal-acwy",
+    atc: "J07AH08",
+    components: ["meningococcal-acwy"],
+    typicalSeriesDoses: 1,
+    boosterIntervalMonths: null,
+    category: "indication",
+    source: STIKO,
+    synonyms: ["meningococcus acwy", "quadrivalent meningococcal"],
+  },
+  {
+    slug: "meningococcal-b",
+    atc: "J07AH09",
+    components: ["meningococcal-b"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "indication",
+    source: STIKO,
+    synonyms: ["meningococcus b"],
+  },
+  {
+    // The pre-exposure course. What follows an actual exposure is treatment
+    // and is not a schedule this catalogue has an opinion about.
+    slug: "rabies",
+    atc: "J07BG01",
+    components: ["rabies"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: null,
+    category: "indication",
+    source: STIKO,
+    synonyms: ["lyssa"],
+  },
+
+  // ── Monovalent: by destination ──────────────────────────────────────────
+  // Not on the standing-committee schedule, so each cites the WHO position
+  // paper for its own antigen rather than borrowing a citation from a
+  // document that does not cover it.
+  {
+    slug: "typhoid",
+    atc: "J07AP03",
+    components: ["typhoid"],
+    typicalSeriesDoses: 1,
+    boosterIntervalMonths: 36,
+    category: "travel",
+    source: "WHO position paper on typhoid vaccines",
+    synonyms: ["typhoid fever"],
+  },
+  {
+    // One dose is treated as lifelong protection; the certificate that used
+    // to expire after ten years no longer does.
+    slug: "yellow-fever",
+    atc: "J07BL01",
+    components: ["yellow-fever"],
+    typicalSeriesDoses: 1,
+    boosterIntervalMonths: null,
+    category: "travel",
+    source: "WHO position paper on yellow fever vaccines",
+  },
+  {
+    slug: "japanese-encephalitis",
+    atc: "J07BA01",
+    components: ["japanese-encephalitis"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: 12,
+    category: "travel",
+    source: "WHO position paper on Japanese encephalitis vaccines",
+  },
+  {
+    // Oral, and the only entry here whose route is not an injection — which
+    // is why route derives from the antigen at the export boundary rather
+    // than being asked of the person filling in the form.
+    slug: "cholera",
+    atc: "J07AE01",
+    components: ["cholera"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: 24,
+    category: "travel",
+    source: "WHO position paper on cholera vaccines",
+  },
+
+  // ── Combinations ────────────────────────────────────────────────────────
+  {
+    // The adult refresher most Passes are full of.
+    slug: "td",
+    atc: "J07AM51",
+    components: ["tetanus", "diphtheria"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: 120,
+    category: "standard",
+    source: STIKO,
+    synonyms: ["tetanus diphtheria"],
+  },
+  {
+    slug: "tdap",
+    atc: "J07AJ52",
+    components: ["tetanus", "diphtheria", "pertussis"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: 120,
+    category: "standard",
+    source: STIKO,
+    synonyms: ["tetanus diphtheria pertussis"],
+  },
+  {
+    slug: "tdap-ipv",
+    atc: "J07CA02",
+    components: ["tetanus", "diphtheria", "pertussis", "polio"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: 120,
+    category: "standard",
+    source: STIKO,
+  },
+  {
+    // The childhood preparation. Same ATC code as the adult one above: ATC
+    // classifies the antigen combination and does not distinguish the
+    // full-strength form from the reduced-antigen one.
+    slug: "dtap-ipv",
+    atc: "J07CA02",
+    components: ["diphtheria", "tetanus", "pertussis", "polio"],
+    typicalSeriesDoses: 4,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+  },
+  {
+    // Six antigens in one injection, which is what makes an infant Pass page
+    // short and this catalogue's component axis necessary: one line here
+    // counts into six separate series.
+    slug: "hexavalent",
+    atc: "J07CA09",
+    components: [
+      "diphtheria",
+      "tetanus",
+      "pertussis",
+      "polio",
+      "hib",
+      "hepatitis-b",
+    ],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+    synonyms: ["six-in-one"],
+  },
+  {
+    slug: "mmr",
+    atc: "J07BD52",
+    components: ["measles", "mumps", "rubella"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+    synonyms: ["measles mumps rubella"],
+  },
+  {
+    slug: "mmrv",
+    atc: "J07BD54",
+    components: ["measles", "mumps", "rubella", "varicella"],
+    typicalSeriesDoses: 2,
+    boosterIntervalMonths: null,
+    category: "childhood",
+    source: STIKO,
+    synonyms: ["measles mumps rubella varicella"],
+  },
+  {
+    slug: "hepa-hepb",
+    atc: "J07BC20",
+    components: ["hepatitis-a", "hepatitis-b"],
+    typicalSeriesDoses: 3,
+    boosterIntervalMonths: null,
+    category: "travel",
+    source: STIKO,
+    synonyms: ["hepatitis a and b"],
+  },
+  {
+    slug: "hepa-typhoid",
+    atc: "J07CA10",
+    components: ["hepatitis-a", "typhoid"],
+    typicalSeriesDoses: 1,
+    boosterIntervalMonths: null,
+    category: "travel",
+    source: "WHO position paper on typhoid vaccines",
+  },
+];
+
+/** Every slug the catalogue currently offers, combinations included. */
+export const VACCINE_CATALOG_SLUGS: readonly string[] = VACCINE_CATALOG.map(
+  (entry) => entry.slug,
+);
+
+const BY_SLUG = new Map<string, VaccineSeed>(
+  VACCINE_CATALOG.map((entry) => [entry.slug, entry]),
+);
+
+/**
+ * The one lookup path into the catalogue.
+ *
+ * Returns `null` for anything it does not know — an empty slug, a slug a past
+ * release wrote and this one no longer lists, a slug restored verbatim from a
+ * backup written by an older version. It never throws, because every one of
+ * those is a real row belonging to a real person, and the caller's answer is
+ * to fall back to the record's own `vaccineName` rather than to fail.
+ */
+export function resolveCatalogEntry(
+  slug: string | null | undefined,
+): VaccineSeed | null {
+  if (!slug) return null;
+  return BY_SLUG.get(slug) ?? null;
+}
+
+/**
+ * The antigens a dose with this slug counts into.
+ *
+ * Empty for an unknown slug and for a free-text-only record: a name string is
+ * not evidence about which antigens were given, and guessing from one is how
+ * a booster reminder would be cleared by a dose that never contained it.
+ */
+export function componentsForSlug(
+  slug: string | null | undefined,
+): readonly AntigenSlug[] {
+  return resolveCatalogEntry(slug)?.components ?? [];
+}