Viral Hepatitis – Vaccines, Serology & Pharmacotherapy

Vocabulary flashcards summarizing key terms, vaccines, serology markers, antiviral agents, adverse effects, and monitoring parameters for hepatitis A, B, and C.

Hepatitis A Virus (HAV)

Picornavirus transmitted fecal-orally; produces acute, self-limiting hepatitis without chronic infection.

Fecal-oral transmission

Route in which pathogens are shed in feces and ingested through contaminated food, water, or hands.

IgM anti-HAV

First antibody to appear after HAV infection; marker of acute or recent disease.

IgG anti-HAV

Long-lasting antibody indicating past HAV infection or successful vaccination; confers immunity.

HAVRIX

Inactivated HAV vaccine, 1 mL IM at 0 and 6–12 months for hepatitis A prevention.

VAQTA

Inactivated HAV vaccine, 1 mL IM at 0 and 6–18 months for hepatitis A prevention.

TWINRIX

Combined HAV/HBV vaccine, 1 mL IM at 0, 1, 6 months (or accelerated 0, 7, 21-30 days + 20-month booster).

GamaSTAN

Human immune globulin for pre- or post-exposure HAV prophylaxis when vaccine is contraindicated or for infants <1 yr.

Hepatitis B Virus (HBV)

DNA hepadnavirus spread by blood and body fluids; can cause chronic liver infection, cirrhosis, and cancer.

HBsAg

Hepatitis B surface antigen; its presence indicates active HBV infection (acute or chronic).

Anti-HBs

Antibody to HBsAg; indicates immunity from vaccination or recovery from infection.

Anti-HBc

Antibody to HBV core antigen; denotes past or current natural HBV infection (not produced by vaccine).

HBeAg

Envelope antigen signifying active viral replication and high infectivity in HBV infection.

Anti-HBe

Antibody to envelope antigen; seroconversion suggests lower HBV replication and infectivity.

Tenofovir disoproxil fumarate (TDF)

Oral nucleotide analogue for chronic HBV (300 mg daily); risks include nephropathy, ↓BMD, and Fanconi syndrome.

Tenofovir alafenamide (TAF)

Prodrug of tenofovir (25 mg daily) preferred in HBV for lower renal and bone toxicity compared with TDF.

Entecavir

Nucleoside analogue for chronic HBV (0.5 mg daily on empty stomach); boxed warning for lactic acidosis and severe HBV flare.

Pegylated interferon-α

Long-acting cytokine given 180 µg SQ weekly for HBV; induces immune antiviral response but causes flu-like and psychiatric ADRs.

Nucleos(t)ide analogues (HBV)

Oral antivirals that mimic natural nucleosides, inhibit HBV DNA polymerase, cause chain termination, and suppress replication.

Acute HBV exacerbation (BBW)

Severe hepatitis flare that can occur after stopping HBV antivirals such as TDF, TAF, or entecavir.

Hepatitis C Virus (HCV)

RNA flavivirus transmitted mainly by blood; often becomes chronic, leading to cirrhosis and hepatocellular carcinoma.

Direct Acting Antivirals (DAA)

Oral agents targeting specific HCV proteins; achieve high cure rates but carry boxed warning for HBV reactivation.

NS3/4A protease inhibitors

DAA class (e.g., glecaprevir, grazoprevir, voxilaprevir) blocking HCV polyprotein cleavage; CI in decompensated cirrhosis.

NS5B polymerase inhibitor

DAA class represented by sofosbuvir; inhibits HCV RNA-dependent RNA polymerase, halting genome replication.

NS5A inhibitor

DAA class (pibrentasvir, velpatasvir, ledipasvir, elbasvir) disrupting HCV RNA replication complex and virion assembly.

Glecaprevir

NS3/4A protease inhibitor component of Mavyret; absorption markedly increases with food.

Pibrentasvir

Potent pan-genotypic NS5A inhibitor paired with glecaprevir in Mavyret.

Sofosbuvir

Nucleotide analogue NS5B inhibitor present in Harvoni, Epclusa, and Vosevi; avoid with strong P-gp inducers.

Velpatasvir

Pan-genotypic NS5A inhibitor combined with sofosbuvir in Epclusa and with voxilaprevir in Vosevi.

Ledipasvir

NS5A inhibitor paired with sofosbuvir in Harvoni; absorption reduced by acid-suppressive therapy.

Grazoprevir

NS3/4A protease inhibitor combined with elbasvir in Zepatier; contraindicated with cyclosporine.

Voxilaprevir

Protease inhibitor added to sofosbuvir/velpatasvir in Vosevi for patients who failed prior NS5A therapy.

Mavyret

Glecaprevir/pibrentasvir regimen, 3 tabs with food x 8 weeks; treats all HCV genotypes but CI in Child-Pugh B/C.

Harvoni

Ledipasvir/sofosbuvir once daily for 12 weeks (8 weeks in select GT1 pts); interacts with PPIs and amiodarone.

Epclusa

Sofosbuvir/velpatasvir once daily for 12 weeks; pan-genotypic, needs RAS testing in GT3 cirrhosis.

Zepatier

Elbasvir/grazoprevir 12-week regimen for GT1 or 4; avoid in decompensated cirrhosis and with cyclosporine.

Vosevi

Triple combo sofosbuvir/velpatasvir/voxilaprevir reserved for prior DAA failures; taken with food for 12 weeks.

Ribavirin

Weight-based oral nucleoside analog used with DAAs in select cases; BBWs for hemolytic anemia and teratogenicity.

Sustained Virologic Response (SVR12)

Undetectable HCV RNA 12 weeks after therapy completion; considered a clinical cure.

FibroScan (Transient elastography)

Non-invasive ultrasound technique measuring liver stiffness to stage fibrosis (F0–F4).

APRI score

AST-to-platelet ratio index;

FIB-4 score

Composite index (age, AST, ALT, platelets) to estimate liver fibrosis;

Cryoglobulinemic vasculitis

Immune complex small-vessel vasculitis associated with chronic HCV causing purpura, arthralgia, and neuropathy.

HBV reactivation (DAA BBW)

Resurgence of HBV replication during or after HCV DAA therapy; necessitates HBV screening and prophylaxis.

Fanconi syndrome

Proximal renal tubular dysfunction causing phosphate wasting; notable adverse effect of TDF therapy.