Last updated: August 8, 2026
GSK's Arexvy is the leading commercial product in the adjuvanted respiratory syncytial virus vaccine market. Its initial launch generated more than £1 billion in first-year sales, but demand has become more dependent on adult vaccination recommendations, seasonal uptake, payer coverage and competition from Pfizer's Abrysvo and Moderna's mResvia. The near-term market is commercially attractive, while long-term growth depends on repeat vaccination guidance, expansion into younger adults and possible pediatric or maternal indications.
What is the adjuvanted RSV vaccine?
The adjuvanted RSV vaccine is Arexvy, a recombinant prefusion F protein vaccine developed by GSK Biologicals. It uses the RSVPreF3 antigen with the AS01E adjuvant system.
| Product |
Company |
FDA approval |
Initial target population |
Technology |
| Arexvy |
GSK |
May 2023 |
Adults age 60 and older |
RSVPreF3 antigen with AS01E adjuvant |
| Abrysvo |
Pfizer |
May 2023 |
Adults age 60 and older; later maternal immunization and younger adults |
Bivalent RSV prefusion F protein |
| mResvia |
Moderna |
May 2024 |
Adults age 60 and older |
Messenger RNA vaccine |
The FDA initially approved Arexvy for adults age 60 and older. In June 2024, the FDA expanded the label to adults age 50 through 59 who are at increased risk of RSV lower respiratory tract disease.[1] The product is administered as a single intramuscular dose.
How large is the RSV vaccine market?
The adult RSV vaccine market is concentrated among three manufacturers and is driven largely by the United States. GSK entered the market first with Arexvy, Pfizer followed with Abrysvo, and Moderna entered in 2024.
The U.S. Centers for Disease Control and Prevention recommends RSV vaccination for:
- All adults age 75 and older.
- Adults age 60 through 74 who are at increased risk of severe RSV disease.
- Adults age 50 through 59 who are at increased risk, subject to product labeling and clinical assessment.
The recommendations are generally structured around a single lifetime dose unless future evidence supports revaccination. This creates a large initial addressable population but limits recurring annual revenue compared with influenza vaccines.
Market drivers
The main demand drivers are:
- Aging populations and higher prevalence of chronic cardiopulmonary disease.
- Physician awareness of RSV hospitalization risk in older adults.
- Expanded recommendations for adults age 50 through 59 at elevated risk.
- Coverage through Medicare and commercial insurance.
- Greater use of pharmacy-based adult immunization.
- Clinical evidence supporting protection against RSV lower respiratory tract disease.
The principal constraints are low adult vaccination rates, uncertainty about the need for revaccination, seasonal administration, competing vaccines and reimbursement friction.
What are Arexvy's sales and financial trajectory?
Arexvy had one of the fastest launches in the vaccine sector. GSK reported first-year sales of approximately £1.2 billion in 2023, reflecting the product's launch in the United States and other markets.[2]
| Financial metric |
Approximate result |
| 2023 sales |
About £1.2 billion |
| 2023 commercial status |
GSK's first full launch year |
| 2024 market condition |
More competitive, with lower launch novelty |
| Long-term company target |
GSK has identified RSV as a major growth opportunity |
The 2023 result benefited from several factors: first-mover status, strong pre-season stocking, high physician attention and broad initial eligibility for adults age 60 and older. The same factors are difficult to repeat in subsequent years.
The financial trajectory is likely to have three stages:
Launch phase
The launch phase produced rapid revenue because pharmacies, health systems and physicians prepared for the first adult RSV vaccination season. Initial uptake was concentrated among older adults and those with chronic disease.
Normalization phase
Sales growth is expected to moderate as the previously unvaccinated population declines. The market shifts from broad population capture to targeted vaccination based on age, risk status and physician recommendation.
Expansion phase
Future growth depends on label expansion, international penetration, better adult vaccine infrastructure and evidence supporting revaccination. The 50-to-59 indication expands the theoretical market, but the high-risk qualification limits the immediate commercial effect.
GSK has described RSV as a major vaccine growth opportunity, but peak-sales estimates are more sensitive to vaccination policy than traditional pharmaceutical forecasts. The key variables are the percentage of eligible adults vaccinated, the frequency of future doses and whether recommendations expand to broader age groups.
How does Arexvy compare with Abrysvo and mResvia?
Arexvy has an early commercial and clinical positioning advantage, but it does not have exclusive control of the adult RSV vaccine market.
| Attribute |
Arexvy |
Abrysvo |
mResvia |
| Manufacturer |
GSK |
Pfizer |
Moderna |
| Modality |
Recombinant protein |
Recombinant protein |
mRNA |
| Adjuvant |
AS01E |
None disclosed as an adjuvanted product |
No conventional adjuvant |
| FDA adult approval |
2023 |
2023 |
2024 |
| Maternal indication |
No |
Yes |
No |
| Adult age expansion |
50-59 at increased risk |
Label-dependent |
60 and older initially |
| Commercial position |
First entrant and leading launch product |
Strong competitor with maternal franchise |
New entrant with mRNA manufacturing platform |
Abrysvo has an important strategic advantage because Pfizer holds both older-adult and maternal immunization indications. The maternal market is distinct from the older-adult market and could support year-round brand visibility.
mResvia gives Moderna a differentiated platform, but it entered after GSK and Pfizer. Its competitive position depends on durability, safety, manufacturing scale and Moderna's ability to use its respiratory vaccine infrastructure.
What clinical evidence supports Arexvy demand?
In the pivotal AReSVi-006 study, Arexvy demonstrated protection against RSV lower respiratory tract disease in adults age 60 and older. GSK reported vaccine efficacy of 82.6% against a first RSV lower respiratory tract disease episode during the first RSV season.[3]
The clinical value proposition is strongest for adults with:
- Chronic obstructive pulmonary disease.
- Asthma or other chronic respiratory disease.
- Heart failure or cardiovascular disease.
- Diabetes.
- Frailty or immune compromise.
- Advanced age.
Durability is commercially important. A vaccine that protects across multiple seasons is more valuable to payers and physicians, but it could also reduce near-term repeat-dose revenue. GSK has reported continued protection in follow-up analyses, although the precise revaccination schedule remains a regulatory and public-health question.[3]
What is the FDA regulatory status of Arexvy?
Arexvy is FDA-approved as a biologic vaccine. It was approved under the Public Health Service Act for prevention of RSV lower respiratory tract disease in adults age 60 and older, with later expansion to adults age 50 through 59 at increased risk.[1]
The product does not have an annual influenza-style recommendation. CDC guidance uses shared clinical decision-making for certain older adults rather than recommending vaccination for every adult in the relevant age range.
Regulatory factors that could change the market include:
- A formal recommendation for routine revaccination.
- Broader age-based recommendations.
- New evidence on protection against RSV hospitalization.
- Additional international approvals.
- Safety findings affecting use in older adults.
- New maternal or pediatric data.
What is the Orange Book and Purple Book status of Arexvy?
Arexvy is a biologic vaccine and is not typically analyzed through the FDA Orange Book in the same manner as a small-molecule prescription drug. The relevant FDA framework is the Purple Book and the biologic reference-product exclusivity provisions.
Arexvy received FDA approval on May 31, 2023. The statutory reference-product exclusivity period for a newly licensed biologic is generally 12 years from first licensure under the Biologics Price Competition and Innovation Act, subject to the specific regulatory record and statutory treatment of the product.[4]
That framework would place the reference-product exclusivity horizon in 2035. This date is separate from patent expiry and does not by itself establish the earliest possible competitive entry in every scenario.
What patents protect Arexvy?
Arexvy's protection is expected to include patents and patent applications covering the RSV prefusion F antigen, antigen configurations, adjuvanted immunogenic compositions, dosing regimens, manufacturing processes and combinations of RSV antigen with AS01-family adjuvants.
The commercial protection is distributed across several technical categories:
| Protection category |
Relevance to Arexvy |
| RSVPreF3 antigen |
Covers antigen design and immunogenic constructs |
| Prefusion stabilization |
Protects conformationally stabilized RSV F protein |
| AS01E adjuvant use |
Protects or supports the immune-enhancing formulation |
| Antigen-adjuvant composition |
Addresses the combined vaccine formulation |
| Manufacturing process |
Can create practical barriers even after composition claims weaken |
| Dosing and revaccination methods |
May protect selected administration schedules |
No single Orange Book patent entry controls Arexvy's market entry analysis. Public regulatory materials do not identify a single, definitive patent expiration date that can be treated as the product's terminal protection date. Patent term adjustments, continuations, terminal disclaimers, foreign prosecution and claim scope must be assessed patent by patent.
When does Arexvy lose exclusivity?
The practical exclusivity timeline has several layers:
| Event |
Timing |
| FDA approval |
May 31, 2023 |
| Statutory biologic reference-product exclusivity |
Generally through May 2035 |
| Patent expiry |
Patent-specific and potentially later than regulatory exclusivity |
| Biosimilar or follow-on vaccine entry |
Dependent on regulatory pathway and enforceable patent claims |
| Generic substitution |
Not expected through the conventional small-molecule generic pathway |
The likely competitive threat is not a traditional ANDA generic. A follow-on biologic or competing vaccine would need to address a complex biological product, clinical comparability, manufacturing controls, antigen structure and adjuvant composition.
For vaccines, interchangeability and automatic pharmacy substitution also operate differently from small-molecule generic substitution. Market entry therefore depends on regulatory approval, supply capacity, payer positioning and physician adoption, not only on patent expiration.
Are there Paragraph IV challenges or patent litigation involving Arexvy?
No major publicly reported Paragraph IV campaign is associated with Arexvy as of the available launch-period public record. Paragraph IV litigation is primarily an Abbreviated New Drug Application mechanism for small-molecule products. It is not the standard framework for a complex biologic vaccine such as Arexvy.
The more relevant litigation risks would involve:
- Patent infringement claims against a follow-on RSV vaccine.
- Licensing disputes involving antigen or adjuvant technology.
- Inventorship or ownership disputes.
- Manufacturing-process patents.
- Contract disputes involving adjuvant supply or production.
- Regulatory exclusivity challenges.
The absence of a prominent Paragraph IV dispute does not mean that Arexvy has no patent risk. It means the product's competitive pathway is more likely to involve biologic regulation and patent litigation than an ANDA filing.
What manufacturing and intellectual-property barriers protect Arexvy?
The AS01E adjuvant system creates a meaningful manufacturing and supply barrier. A competitor must produce a biologically active antigen, formulate it consistently with the adjuvant, meet potency and stability specifications, and scale production for seasonal demand.
The manufacturing risks include:
- Antigen yield and purity.
- Preservation of the prefusion F conformation.
- Adjuvant raw-material supply.
- Batch consistency.
- Cold-chain management.
- Fill-finish capacity.
- Seasonal inventory planning.
These barriers can preserve commercial value after some patent claims expire. A technically substitutable product still requires regulatory validation and sufficient manufacturing capacity.
Which companies are challenging GSK in the RSV vaccine market?
Pfizer is the most direct commercial competitor through Abrysvo. Its maternal indication gives it a market segment that Arexvy does not currently serve.
Moderna is challenging both products through mResvia and could use its mRNA platform to pursue updated formulations, combination respiratory vaccines or rapid strain-response programs.
Sanofi and AstraZeneca compete in infant RSV prevention through Beyfortus, a long-acting monoclonal antibody. Beyfortus is not a vaccine, but it competes for healthcare budgets and RSV prevention attention in pediatric settings.
The competitive landscape is therefore segmented:
- Older adults: Arexvy, Abrysvo and mResvia.
- Pregnant individuals: Abrysvo and infant monoclonal-antibody alternatives.
- Infants: Beyfortus and maternal immunization.
- Future combination products: potential competition from integrated influenza, COVID-19 and RSV vaccines.
How much revenue is exposed to RSV vaccine competition?
GSK's revenue exposure is material because Arexvy generated more than £1 billion shortly after launch. The product is strategically important within GSK's vaccine portfolio, but it is not the company's only major growth driver.
The largest financial risks are:
- A lower-than-expected second-season vaccination rate.
- Narrow CDC eligibility criteria.
- Payer resistance to vaccination outside the oldest age groups.
- Abrysvo's maternal and adult market presence.
- mResvia's entry into the premium vaccine market.
- Lack of a near-term revaccination recommendation.
- Seasonal manufacturing overcapacity.
- Adverse safety signals or declining physician confidence.
The largest upside drivers are broader 50-to-59 uptake, stronger real-world effectiveness data, routine vaccination for additional age groups and a defined revaccination schedule.
What generic or follow-on launch scenarios exist for Arexvy?
The most plausible launch scenarios are:
Early competitive entry before patent expiry
A competitor could seek approval based on a distinct antigen or formulation that avoids GSK's enforceable claims. This would require meaningful clinical and manufacturing investment.
Follow-on biologic entry after regulatory exclusivity
A later entrant could pursue a biologic pathway after the reference-product exclusivity period, subject to FDA requirements and patent litigation.
Non-infringing competitor vaccines
A competing RSV vaccine could enter without copying Arexvy's antigen-adjuvant combination. Abrysvo and mResvia already demonstrate that the market does not depend on a single technological platform.
Product substitution without automatic interchangeability
Hospitals, pharmacies and payers could use a rival vaccine even without formal interchangeability, particularly if the rival has lower pricing, broader indications or better supply.
Key Takeaways
- Arexvy is GSK's adjuvanted RSV vaccine and the first major commercial product in the adult RSV vaccine market.
- GSK generated approximately £1.2 billion in Arexvy sales in 2023.
- Growth after launch depends on adult vaccination rates, CDC recommendations, payer coverage and revaccination policy.
- Pfizer's Abrysvo is the strongest direct competitor because it covers older adults and has a maternal indication.
- Moderna's mResvia adds mRNA-based competition but entered after GSK and Pfizer.
- Arexvy's biologic exclusivity horizon generally extends to 2035, while patent expiry is claim-specific and may extend beyond that date.
- Paragraph IV litigation is not the principal competitive pathway for this biologic vaccine.
- The strongest barriers are the antigen-adjuvant formulation, manufacturing controls, clinical validation and seasonal supply execution.
- Revenue risk is concentrated in the post-launch normalization period, when broad first-time vaccination gives way to targeted annual demand.
FAQs
Does Arexvy require annual vaccination?
No. Current U.S. recommendations generally call for a single RSV vaccine dose, and routine annual revaccination has not been established.
Is Arexvy interchangeable with Abrysvo?
The products compete in the same adult market, but commercial use and substitution depend on regulatory labeling, payer policies and clinical judgment. They should not be treated as conventional interchangeable generic products.
Can a biosimilar company launch a copy of Arexvy?
A follow-on biologic may eventually be possible, but a conventional small-molecule generic pathway is not the expected route. Antigen structure, adjuvant composition, manufacturing and clinical comparability create substantial barriers.
Does GSK own the entire adult RSV vaccine market?
No. Pfizer and Moderna compete directly in older adults. Pfizer also has a maternal immunization position that GSK does not currently match.
What would most increase Arexvy's peak sales?
The largest potential drivers are broader age-based recommendations, strong evidence for revaccination, higher pharmacy vaccination rates and expansion into additional RSV prevention populations.
References
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U.S. Food and Drug Administration. (2024). FDA approves expanded indication for GSK's Arexvy RSV vaccine in adults 50 through 59 at increased risk. https://www.fda.gov/
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GSK plc. (2024). Annual report 2023. https://www.gsk.com/en-gb/investors/annual-report/
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GSK plc. (2024). Arexvy clinical efficacy and long-term follow-up data. https://www.gsk.com/en-gb/media/press-releases/
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U.S. Food and Drug Administration. (2024). Purple Book: Database of licensed biological products. https://purplebooksearch.fda.gov/
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Centers for Disease Control and Prevention. (2024). RSV vaccination for older adults. https://www.cdc.gov/rsv/vaccines/older-adults.html
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U.S. Food and Drug Administration. (2024). FDA approves mRNA RSV vaccine for older adults. https://www.fda.gov/ 久久精品
