AAV vs Lentivirus Production: Manufacturing, Yield and Use-Case Guide
Choose based on delivery route, not brand. AAV wins for in vivo gene therapy into non-dividing tissue with transgenes under 4.7 kb. Lentivirus wins for ex vivo modification of dividing cells (CAR-T, hematopoietic stem cells) and larger payloads up to 8 kb. AAV scales to 2000 L bioreactors. Lentivirus is capped by a 48 to 72 hour productive window and typically runs 50 to 500 L.
Key differences at a glance
- AAV: ~25 nm non-enveloped icosahedral capsid, 4.7 kb ssDNA payload, episomal expression, scales to 2000 L, dominant for in vivo gene therapy.
- Lentivirus: 100 to 200 nm enveloped particle, 8 kb RNA payload, integrates into host genome, 50 to 500 L typical scale, dominant for ex vivo CAR-T and HSC gene therapy.
- Yield difference: AAV produces 1E11 to 1E14 vg/mL crude (physical particles). Lentivirus produces 1E7 to 1E10 TU/mL crude (functional transducing units). The units are not directly comparable but AAV is higher on physical particle counts.
- Best for in vivo delivery to liver, retina, muscle, CNS: AAV.
- Best for ex vivo T cell, HSC, iPSC engineering: Lentivirus.
Side-by-side comparison
| Factor | AAV | Lentivirus |
|---|---|---|
| Particle size | ~25 nm, non-enveloped | 100 to 200 nm, enveloped |
| Genome | ssDNA | ssRNA (reverse-transcribed to DNA) |
| Packaging capacity | ~4.7 kb | ~8 kb |
| Integration into host genome | Episomal (very low integration) | Integrating (SIN-LV reduces oncogenic risk) |
| Dividing cell transduction | Poor (episome diluted by division) | Excellent (passed to daughters) |
| Non-dividing cell transduction | Excellent (retina, CNS, muscle, liver) | Good (VSV-G pseudotyped) |
| Typical crude titer | 1E11 to 1E14 vg/mL (physical) | 1E7 to 1E10 TU/mL (functional) |
| Bioreactor scale | 200 to 2000 L stirred tank / SUB | 50 to 500 L (VSV-G toxicity ceiling) |
| Storage / cold chain | 2 to 8 °C for weeks; −80 °C for long term | −80 °C mandatory; 20 to 50% titer loss per freeze-thaw |
| Delivery model | In vivo (direct patient injection) | Ex vivo (apheresis to transduce to reinfuse) |
Values reflect typical published specifications for suspension HEK293 production. Vendor datasheets and your specific serotype or pseudotype take precedence. See our AAV production yield guide and lentiviral vector production guide for parameter-level detail.
AAV in detail
Adeno-associated virus is a small, non-pathogenic parvovirus with a 25 nm icosahedral capsid and a 4.7 kb single-stranded DNA genome. Recombinant AAV (rAAV) is produced by removing the wild-type Rep and Cap genes from the vector genome (keeping only the two ITRs flanking the transgene of interest) and supplying Rep and Cap in trans, along with adenoviral helper functions (E2A, E4, VA RNA). Thirteen natural serotypes and hundreds of engineered capsid variants let researchers target specific tissues: Spark Therapeutics uses AAV2 for the retina in Luxturna, Novartis uses AAV9 for CNS in Zolgensma, and Sarepta Therapeutics uses AAVrh74 for skeletal muscle in Elevidys.
How it works
Production is dominated by transient triple transfection of suspension HEK293 cells with plasmids encoding the ITR-transgene, RepCap, and adenoviral helper functions. Delivery uses Polyplus PEIpro, Thermo Fisher ExpiFectamine or an equivalent cationic reagent. AAV assembles inside the cell nucleus over 72 hours. Downstream harvest uses cell lysis (Triton, Tween, or freeze-thaw) then endonuclease digestion, clarification, affinity capture on an AAVX or AAV9-specific resin, and anion exchange or CsCl gradient to separate full from empty capsids. Alternative platforms include stable producer cell lines from Cytiva (ELEVECTA), Asimov (AAV Edge) and Lonza, plus the baculovirus/Sf9 system used by Roche for Elevidys manufacturing.
When AAV wins
AAV dominates when the therapeutic gene fits under 4.7 kb and the delivery target is a non-dividing tissue accessible by injection: retinal photoreceptors, spinal motor neurons, hepatocytes, cardiomyocytes, skeletal muscle. Because the episomal genome is not diluted by cell division, expression can persist for years in a quiescent tissue from a single dose. Serotype engineering gives fine control over tissue tropism, which is not really possible for lentivirus. The AAV Yield Calculator lets you estimate vg per batch from cell density and specific productivity.
Lentivirus in detail
Lentivirus is a genus of retroviruses that includes HIV-1, from which most third-generation lentiviral vectors are derived. The vector particle is 100 to 200 nm with a lipid envelope displaying an envelope glycoprotein (usually VSV-G for broad tropism, but measles H/F, baboon endogenous, or cocal envelope are also used). Inside the envelope, a conical capsid holds two copies of about 8 kb single-stranded RNA. On entry, reverse transcriptase converts the RNA to double-stranded DNA and integrase inserts it into the host chromosome, giving permanent expression that survives cell division. The three-plasmid third-generation SIN system splits gag-pol, rev and env onto separate plasmids and deletes the U3 enhancer in the LTR, lowering the risk of insertional oncogenesis. Vendors and CDMOs in this space include Oxford Biomedica, Lonza, WuXi Advanced Therapies, MilliporeSigma and Yposkesi.
How it works
Suspension HEK293T cells are transfected with four plasmids: transfer (containing the transgene between LTRs), gag-pol (structural proteins), rev (RNA export) and envelope (VSV-G by default). PEI delivers the plasmid cocktail at 1 to 2 µg total DNA per million cells. Lentivirus buds continuously from the plasma membrane, so harvest is from the supernatant rather than cell lysate. The productive window is 48 to 72 hours before VSV-G cytotoxicity limits further production. Downstream uses tangential flow filtration for concentration, benzonase to remove residual DNA, mixed-mode or anion exchange chromatography, and sterile filtration. Cold chain is unforgiving: lentivirus loses 20 to 50% functional titer per freeze-thaw, so fill-finish and shipping are engineered around single-use aliquots stored at −80 °C. See our detailed lentiviral vector manufacturing guide for a 50 L bioreactor walk-through.
When lentivirus wins
Lentivirus dominates ex vivo cell therapy. When you extract T cells or CD34+ hematopoietic stem cells from a patient, transduce them in a closed-system bag or bioreactor with lentiviral vector, and reinfuse, the modified genes need to persist through the many divisions those cells undergo after re-engraftment. That is only possible with an integrating vector. All approved CAR-T products (Kymriah, Yescarta, Tecartus, Breyanzi, Abecma, Carvykti) and the approved lentiviral HSC therapies (Zynteglo, Skysona, Lyfgenia) rely on this integration property. The 8 kb payload also matters for constructs like bicistronic CARs with a safety switch, or gene addition of dystrophin fragments where AAV's 4.7 kb ceiling cannot fit the required cargo.
Pros and cons
AAV
Advantages
- Non-pathogenic, non-integrating, low insertional mutagenesis risk.
- Scales cleanly to 2000 L stirred-tank on a robust suspension HEK293 platform.
- Thirteen or more natural serotypes and hundreds of engineered capsids for tissue-specific targeting.
- Direct in vivo delivery: no apheresis, no ex vivo cell processing, no reinfusion.
Disadvantages
- 4.7 kb packaging limit rules out large genes (dystrophin, CFTR, factor VIII require truncation or dual-vector tricks).
- Pre-existing neutralising antibodies in 30 to 60% of adults exclude patients or require immune suppression.
- High per-dose vector requirement (up to 1E14 vg/kg systemic) drives GMP manufacturing cost.
- Empty capsid removal is a downstream burden (10 to 70% of physical particles are empty in crude harvest).
Lentivirus
Advantages
- Permanent integration gives durable expression in dividing cells (T, B, HSC).
- ~8 kb payload accommodates bicistronic CARs, multi-cassette editors, larger transgenes.
- Broad tropism via VSV-G pseudotyping; alternative envelopes for cell-selective targeting.
- Strong clinical precedent: six approved CAR-T products and three HSC therapies as of 2026.
Disadvantages
- Insertional oncogenesis risk remains, even with third-generation SIN vectors.
- 48 to 72 hour VSV-G cytotoxicity ceiling caps productive window and complicates scale-up.
- Unforgiving cold chain (−80 °C mandatory; 20 to 50% titer loss per freeze-thaw).
- Requires ex vivo cell processing infrastructure, apheresis, and closed-system transduction.
Which should you choose?
The dominant constraint is almost always delivery route and cell biology, not manufacturing preference. These four scenarios cover most real programmes.
In vivo, non-dividing tissue, gene under 4.7 kb
Retinal dystrophy, spinal motor neuron disease, monogenic liver disease, cardiomyopathy. Direct injection into a stable tissue with a small transgene is exactly what AAV was engineered for.
Choose AAVEx vivo modification of dividing cells (CAR-T, HSC)
B-cell lymphoma, sickle cell disease, beta-thalassemia, cerebral adrenoleukodystrophy, iPSC engineering. Cells will divide many times post-transduction and need heritable expression.
Choose LentivirusTransgene over 5 kb or multi-cassette construct
Full-length dystrophin, CFTR, factor VIII, epigenetic editors with dual promoter cassettes. AAV cannot package without truncation or dual-vector reconstitution.
Choose LentivirusSingle systemic dose, non-integrating preferred
Haemophilia B (Hemgenix), Duchenne (Elevidys), spinal muscular atrophy (Zolgensma). Regulator preference for episomal expression in monogenic in vivo indications is strong.
Choose AAVReal-world use cases
Approved products and late-stage programmes have converged on one platform or the other for reasons that reveal the underlying decision logic.
Zolgensma (spinal muscular atrophy)
Novartis dosed at 1.1E14 vg/kg IV to cross the blood-brain barrier via AAV9 and transduce spinal motor neurons. Single dose, episomal, no ex vivo processing possible in newborns. AAV was the only viable route.
Kymriah (B-ALL, DLBCL)
Novartis apheresed patient T cells, transduced with a lentiviral vector encoding anti-CD19 CAR under EF1α, expanded, and reinfused. Integration was required to survive the many divisions during expansion and post-infusion.
Hemgenix (haemophilia B)
CSL Behring uses AAV5 to deliver factor IX to hepatocytes at 2E13 vg/kg. Liver is a stable episome-friendly tissue and factor IX cDNA is 1.4 kb, well under the 4.7 kb ceiling. A single systemic dose replaces lifelong infusions.
Zynteglo (beta-thalassemia)
bluebird bio harvests CD34+ HSCs, transduces with lentivirus encoding a modified beta-globin gene, and reinfuses after myeloablation. Integration is essential for stable expression across the patient's lifetime of red-cell turnover.
Estimating AAV yield for your batch?
The AAV Yield Calculator converts cell density and specific productivity into vector genomes per batch across suspension bioreactor scales from 50 mL to 2000 L. Use it to sanity-check budget estimates before locking a manufacturing plan.
Open the AAV Yield CalculatorCost and lifecycle considerations
An AAV batch is expensive because every dose is large. A lentiviral batch treats many patients because every dose is small. Compare on cost-per-treated-patient, not cost-per-batch, when evaluating which platform fits your programme economics.
A 200 L GMP AAV batch at a CDMO like Charles River or AGC Biologics is typically around US$2 million all-in, dominated by GMP plasmid DNA ($50k to $150k per gram, 2 to 4 g per batch), transfection reagent, media, and downstream affinity resin. Plasmid alone can account for 30 to 40% of variable cost.
A comparable 200 L lentiviral batch runs around US$1.5 million because plasmid quantities are smaller (four plasmids at roughly 0.5 g each) but per-dose vector requirements are also smaller. A CAR-T dose uses only microgram quantities of lentivirus, so a single 200 L batch can supply hundreds of patients. Independent cost-of-goods analyses estimate lentiviral vector as roughly $5,000 per CAR-T dose, versus $50,000 to $500,000 of AAV per systemic dose in indications like SMA or DMD.
| Cost component | AAV (200 L GMP batch) | Lentivirus (200 L GMP batch) |
|---|---|---|
| Media + reagents | ~$400k | ~$300k |
| GMP plasmid DNA | $200k to $400k | $100k to $200k |
| Downstream (chromatography, empty removal) | ~$700k | ~$500k |
| QC + release testing | ~$400k | ~$400k |
| Total per batch (all-in, CDMO) | ~$2.0M | ~$1.5M |
| Doses per batch (typical) | 1 to 10 systemic; 100+ intravitreal | 200 to 1000 CAR-T |
Vendor landscape
Major CDMOs and platform vendors in each camp, with one-line positioning notes.
AAV production vendors and CDMOs
- Charles River (Cognate): nAAVigation platform, integrated plasmid + AAV. Claims up to 55% shorter GMP timeline than legacy transient.
- Cytiva: ELEVECTA stable producer cell lines and a full end-to-end kit including AAVX affinity resin.
- Lonza: Transient and stable AAV platforms at Houston and Portsmouth GMP sites. Strong late-phase and commercial track record.
- AGC Biologics: Proprietary ProntoLVV and AAV suspension platforms. Global GMP footprint including Copenhagen and Milan.
- Thermo Fisher (Patheon): Plasmid-through-vector integrated services. Large HEK293 suspension capacity.
- Asimov: AAV Edge stable producer platform, engineered HEK293 lines, high volumetric titer targets.
Lentivirus production vendors and CDMOs
- Oxford Biomedica: LentiVector platform pioneered scalable suspension LV. Supplies vector to multiple approved CAR-T products.
- WuXi Advanced Therapies: Integrated LV plus autologous cell therapy manufacturing. Large multi-modality footprint.
- MilliporeSigma: Full LV service including analytics. Supplies process reagents and closed-system consumables.
- Yposkesi (SK pharmteco): European GMP LV and AAV CDMO. Corbeil-Essonnes and Genopole footprint.
- Lonza: LV suspension platform at Netherlands and Houston. Also runs cell therapy fill-finish.
- Sartorius: Upstream + downstream equipment, single-use bioreactors, and PAT for LV manufacturing.
Frequently asked questions
What is the difference between AAV and lentivirus for gene therapy?
Which produces higher yields, AAV or lentivirus?
What is the packaging capacity of AAV versus lentivirus?
Does lentivirus integrate into the genome and does AAV?
Which is safer for clinical use, AAV or lentivirus?
How much does AAV manufacturing cost compared to lentivirus?
Which approved gene therapies use AAV, and which use lentivirus?
When should I choose AAV over lentivirus for a gene therapy programme?
Resources and references
- Bauler et al., "Production of Lentiviral Vectors Using Suspension Cells Grown in Serum-free Media" (Molecular Therapy Methods & Clinical Development, 2019, DOI 10.1016/j.omtm.2019.11.011) — peer-reviewed method paper reporting suspension yields and downstream recovery.
- Drug Discovery News: AAV vs lentiviral vectors — gene therapy manufacturing platform selection — industry review of yield ranges, cold chain, and scale considerations.
- BioProcess International: AAV Platforms — Challenges and Opportunities — industry overview of AAV platform economics and downstream burden.
- Corning: AAV vs Lentiviral Vectors — Gene Transfer Tools Comparison — accessible primer on packaging capacity, tropism, and delivery model differences.