VIRAZOLE Drug Patent Profile

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Which patents cover Virazole, and what generic alternatives are available?

Virazole is a drug marketed by Bausch and is included in one NDA.

The generic ingredient in VIRAZOLE is ribavirin. There is one drug master file entry for this compound. Two suppliers are listed for this compound. Additional details are available on the ribavirin profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Virazole

A generic version of VIRAZOLE was approved as ribavirin by ZYDUS PHARMS USA on October 28^th, 2005.

Summary for VIRAZOLE

US Patents:	0
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	112
Clinical Trials:	15
Patent Applications:	2,809
Drug Prices:	Drug price information for VIRAZOLE
What excipients (inactive ingredients) are in VIRAZOLE?	VIRAZOLE excipients list
DailyMed Link:	VIRAZOLE at DailyMed

See drug prices for VIRAZOLE

Recent Clinical Trials for VIRAZOLE

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
U.S. Army Medical Research and Development Command	Phase 2
Bausch Health Americas, Inc.	Phase 1
Memorial Sloan Kettering Cancer Center	Early Phase 1

See all VIRAZOLE clinical trials

Pharmacology for VIRAZOLE

Drug Class

Nucleoside Analog Antiviral

Paragraph IV (Patent) Challenges for VIRAZOLE

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
VIRAZOLE	for Inhalation Solution	ribavirin	6 gm/vial	018859	1	2014-05-22

US Patents and Regulatory Information for VIRAZOLE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Bausch	VIRAZOLE	ribavirin	FOR SOLUTION;INHALATION	018859-001	Dec 31, 1985		DISCN	Yes	No

Expired US Patents for VIRAZOLE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Bausch	VIRAZOLE	ribavirin	FOR SOLUTION;INHALATION	018859-001	Dec 31, 1985
Bausch	VIRAZOLE	ribavirin	FOR SOLUTION;INHALATION	018859-001	Dec 31, 1985
Bausch	VIRAZOLE	ribavirin	FOR SOLUTION;INHALATION	018859-001	Dec 31, 1985

EU/EMA Drug Approvals for VIRAZOLE

Company	Drugname	Inn	Product Number / Indication	Status	Generic	Biosimilar	Orphan	Marketing Authorisation	Marketing Refusal
Merck Sharp and Dohme B.V	Rebetol	ribavirin	EMEA/H/C/000246Rebetol is indicated in combination with other medicinal products for the treatment of chronic hepatitis C (CHC) in adults.Rebetol is indicated in combination with other medicinal products for the treatment of chronic hepatitis C (CHC) for paediatric patients (children 3 years of age and older and adolescents) not previously treated and without liver decompensation.	Withdrawn	no	no	no	1999-05-06
Teva B.V.	Ribavirin Teva Pharma B.V.	ribavirin	EMEA/H/C/001064Ribavirin Teva Pharma B.V. is indicated in combination with other medicinal products for the treatment ofchronic hepatitis C (CHC) in adults (see sections 4.2, 4.4, and 5.1).Ribavirin Teva Pharma B.V. is indicated in combination with other medicinal products for the treatment ofchronic hepatitis C (CHC) for paediatric patients (children 3 years of age and older and adolescents) notpreviously treated and without liver decompensation (see sections 4.2, 4.4 and 5.1).	Withdrawn	yes	no	no	2009-07-01
Teva B.V.	Ribavirin Teva	ribavirin	EMEA/H/C/001018Ribavirin Teva is indicated for the treatment of chronic hepatitis C virus (HCV) infection in adults, children 3 years of age and older and adolescents and must only be used as part of a combination regimen with interferon alfa-2b. Ribavirin monotherapy must not be used.There is no safety or efficacy information on the use of Ribavirin with other forms of interferon (i.e. not alfa-2b).Naïve patients Adult patients Ribavirin Teva is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, with elevated alanine aminotransferase (ALT), who are positive for hepatitis C viral ribonucleic acid HCV-RNA.Paediatric patients (children 3 years of age and older and adolescents) Ribavirin Teva is indicated, in a combination regimen with interferon alfa­2b, for the treatment of children and adolescents 3 years of age and older, who have all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, and who are positive for HCV-RNA.When deciding not to defer treatment until adulthood, it is important to consider that the combination therapy induced a growth inhibition that may be irreversible in some patients. The reversibility of growth inhibition is uncertain. The decision to treat should be made on a case by case basis.Previous treatment failure patientsAdult patients Ribavirin Teva is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with chronic hepatitis C who have previously responded (with normalisation of ALT at the end of treatment) to interferon alpha monotherapy but who have subsequently relapsed.	Withdrawn	yes	no	no	2009-03-31
Mylan S.A.S	Ribavirin Mylan (previously Ribavirin Three Rivers)	ribavirin	EMEA/H/C/001185Ribavirin Mylan is indicated for the treatment of chronic hepatitis C and must only be used as part of a combination regimen with interferon alfa-2b (adults, children (three years of age and older) and adolescents). Ribavirin monotherapy must not be used.There is no safety or efficacy information on the use of ribavirin with other forms of interferon (i.e. not alfa-2b).Please refer also to the interferon alfa-2b summary of product characteristics (SmPC) for prescribing information particular to that product.Naïve patientsAdult patientsRibavirin Mylan is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, with elevated alanine aminotransferase (ALT), who are positive for serum hepatitis-C-virus (HCV) RNA.Children and adolescentsRibavirin Mylan is indicated, in a combination regimen with interferon alfa-2b, for the treatment of children and adolescents three years of age and older, who have all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, and who are positive for serum HCV RNA. When deciding to not to defer treatment until adulthood, it is important to consider that the combination therapy induced a growth inhibition. The reversibility of growth inhibition is uncertain. The decision to treat should be made on a case-by-case basis (see section 4.4).Previously treatment-failure patientsAdult patientsRibavirin Mylan is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with chronic hepatitis C who have previously responded (with normalisation of ALT at the end of treatment) to interferon alpha monotherapy but who have subsequently relapsed.	Withdrawn	yes	no	no	2010-06-10
BioPartners GmbH	Ribavirin BioPartners	ribavirin	EMEA/H/C/001184Ribavirin BioPartners is indicated for the treatment of chronic hepatitis-C-virus (HCV) infection in adults, children three years of age and older and adolescents and must only be used as part of a combination regimen with interferon alfa-2b. Ribavirin monotherapy must not be used. There is no safety or efficacy information on the use of ribavirin with other forms of interferon (i.e. not alfa-2b).Naïve patientsAdult patientsRibavirin BioPartners is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, with elevated alanine aminotransferase (ALT), who are positive for hepatitis C viral ribonucleic acid (HCV-RNA) (see section 4.4)Children three years of age and older and adolescentsRibavirin BioPartners is intended for use, in a combination regimen with interferon alfa-2b, for the treatment of children three years of age and older and adolescents, who have all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, and who are positive for HCV-RNA.When deciding to not to defer treatment until adulthood, it is important to consider that the combination therapy induced a growth inhibition. The reversibility of growth inhibition is uncertain. The decision to treat should be made on a case by case basis (see section 4.4).Previous-treatment-failure patientsAdult patientsRibavirin BioPartners is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with chronic hepatitis C who have previously responded (with normalisation of ALT at the end of treatment) to interferon alfa monotherapy but who have subsequently relapsed (see section 5.1).	Withdrawn	yes	no	no	2010-04-06
Schering-Plough Europe	Cotronak	ribavirin	EMEA/H/C/000247Cotronak is indicated for the treatment of chronic hepatitis C and must only be used as part of a combination regimen with peginterferon alfa-2b or interferon alfa-2b. Cotronak monotherapy must not be used.There is no safety or efficacy information on the use of Cotronak with other forms of interferon (i.e., not alfa-2b).Please refer also to the peginterferon alfa-2b or interferon alfa-2b Summary of Product Characteristics (SPC) for prescribing information particular to that product.	Withdrawn	no	no	no	1999-05-07

International Patents for VIRAZOLE

See the table below for patents covering VIRAZOLE around the world.

Country	Patent Number	Title	Estimated Expiration
Argentina	199463	SINTESIS DE NUCLEOSIDOS DE 1,2,4-TRIAZOL-3-SUSTITUIDOS
Argentina	205339	SINTESIS DE 1,2,4-TRIAZOLO-3-CARBOXAMIDAS UTILES COMO AGENTES ANTIVIRALES
Argentina	207138	METODO PARA LA OBTENCION DE 1,2,4-TRIAZOLES N-SUBSTITUIDOS Y SUS SALES DE ADICION
Argentina	224992	METODO PARA LA OBTENCION DE NUCLEOSIDOS DE 1-(BETA-D-RIBOFURANOSIL)-1,2,4-TRIAZOL-3-CARBOXAMIDA
Austria	336199
Austria	A465772
Australia	4215772

Virazole Market Dynamics, Financial Trajectory, FDA Status, and Patent Outlook

Last updated: October 25, 2026

Virazole is the branded inhaled formulation of ribavirin used for severe respiratory syncytial virus, or RSV, lower-respiratory-tract infection in hospitalized infants and young children. Its commercial market is small, specialized, and hospital-based. The product has no meaningful remaining patent or regulatory exclusivity, while demand is constrained by narrow labeling, difficult administration, infection-control requirements, and the expansion of RSV prevention with nirsevimab and maternal vaccination. Public filings do not disclose standalone Virazole revenue, so its financial trajectory can be assessed directionally rather than through product-level sales data.

What is Virazole and who markets it?

Virazole is ribavirin for inhalation solution, supplied as a sterile 6-gram powder that is reconstituted for aerosol administration through the Small Particle Aerosol Generator, or SPAG-2 system. The FDA-approved indication is treatment of hospitalized infants and young children with severe lower respiratory tract infection caused by RSV. The product is not approved as a general outpatient RSV treatment or as a preventive therapy. [1]

Product attribute	Virazole profile
Active ingredient	Ribavirin
Dosage form	Inhalation solution for aerosol administration
Original FDA application	NDA 018657
FDA indication	Severe RSV lower-respiratory-tract infection in hospitalized infants and young children
Administration	Continuous aerosol delivery, generally through SPAG-2
Primary setting	Pediatric hospitals and intensive-care units
Product type	Small-molecule branded hospital drug
Biosimilar pathway	Not applicable
Generic pathway	ANDA for ribavirin inhalation solution
Current patent-based exclusivity	No material unexpired exclusivity identified from the product’s age and public FDA records

The product has been associated with Valeant Pharmaceuticals and later Bausch Health’s U.S. pharmaceutical operations. Corporate ownership and commercialization arrangements have changed over time, but public Bausch Health reporting does not isolate Virazole sales from the company’s broader portfolio. [2]

How large is the Virazole market?

Virazole operates in a narrow treatment segment rather than the broader RSV market. RSV has a large epidemiological footprint, but only a small subset of infected children receive aerosolized ribavirin. Most patients with RSV receive supportive care, while preventive products are used to reduce severe disease risk.

The principal demand constraints are:

1. Virazole is labeled for severe disease in hospitalized pediatric patients.
2. Administration requires specialized aerosol equipment and trained staff.
3. Aerosolized ribavirin creates occupational exposure and room-management concerns.
4. Treatment is resource-intensive compared with supportive care.
5. Many hospitals have reduced or eliminated routine use because evidence of clinical benefit is limited or inconsistent.
6. RSV prevention has expanded through long-acting monoclonal antibodies and maternal immunization.

The American Academy of Pediatrics has historically treated ribavirin as a therapy with limited and highly selective use. Clinical practice has generally reserved it for exceptional cases, such as severe disease in high-risk patients or immunocompromised populations, although institutional protocols differ. [3]

What is the competitive landscape for Virazole?

Virazole competes against treatment decisions rather than against a single equivalent branded product.

Competitive option	Relationship to Virazole	Commercial effect
Supportive care	Main clinical alternative for most RSV patients	Reduces eligible treatment volume
Palivizumab	Preventive monoclonal antibody, not a treatment substitute	Historically reduced severe RSV risk in selected infants
Nirsevimab	Long-acting RSV preventive antibody	Further limits severe RSV cases eligible for treatment
Maternal RSV vaccination	Prevents severe infant RSV disease	May reduce future hospitalizations
Oral or intravenous ribavirin	Same active ingredient but different use cases	Does not provide a direct aerosol substitute
Investigational antivirals	Potential future treatment competitors	Could displace Virazole if approved and easier to administer

Nirsevimab, marketed as Beyfortus by AstraZeneca and Sanofi, received FDA approval in 2023 for prevention of RSV lower respiratory tract disease in neonates and infants entering their first RSV season and certain children entering a second season. It is not indicated to treat established infection, but prevention can reduce the number of severe cases that reach the Virazole treatment pathway. [4]

What is the FDA regulatory status of Virazole?

Virazole remains an FDA-approved product under NDA 018657. The approved use is narrow and does not extend to routine treatment of adults, uncomplicated RSV, or prophylaxis. The product label carries substantial warnings related to reproductive toxicity, aerosol exposure, hemolytic anemia, and use in ventilated patients. [1]

Does Virazole have FDA exclusivity?

No meaningful current FDA regulatory exclusivity is expected. Virazole was approved decades ago, and its original approval-era exclusivity periods have expired. Any commercial protection would therefore depend on manufacturing capability, supply reliability, institutional purchasing arrangements, and clinical familiarity rather than FDA exclusivity.

What is the Orange Book status of Virazole?

Virazole is an NDA drug listed in FDA product records under ribavirin inhalation formulations. The Orange Book is relevant for identifying listed patents, therapeutic-equivalence information, and approved products. The product’s age means that any original compound, formulation, or method patents would ordinarily have expired. [5]

A definitive current Orange Book determination must be based on the latest FDA edition and the relevant NDA record. Publicly available product history does not indicate a commercially meaningful, unexpired patent barrier protecting the active ingredient or the original aerosol formulation.

What patents protect Virazole?

Virazole’s patent position is weak from a current market-exclusivity perspective.

Ribavirin was discovered and commercialized decades ago. The active ingredient is long off patent, and the original aerosol product predates the modern patent-term framework. Any patents covering ribavirin itself, its early pharmaceutical compositions, or the original inhalation use would have expired long ago.

Protection category	Current commercial assessment
Ribavirin active ingredient	Expired
Original inhalation formulation	Expected expired
Original RSV treatment method	Expected expired
SPAG-2 administration technology	Any relevant early patents expected expired
Newer manufacturing process	Could be separately protected if developed, but no material product-level barrier is publicly established
Regulatory exclusivity	Expired
Biosimilar exclusivity	Not applicable

The remaining barrier is operational. A competitor would need a compliant ribavirin inhalation product, validated manufacturing controls, appropriate labeling, and a practical delivery system. Those factors can delay entry even when patent protection is absent, but they do not provide legally enforceable exclusivity comparable to an active composition patent.

When does Virazole lose exclusivity?

Virazole lost meaningful market exclusivity many years ago. The relevant commercial question is not a future patent cliff. It is whether a generic manufacturer has sufficient economic incentive to enter a small, technically demanding hospital market.

Virazole therefore has a post-exclusivity profile:

• No expected future compound-patent cliff.
• No biosimilar transition.
• No known pediatric exclusivity extending the current product life.
• Limited substitution because aerosol delivery and hospital protocols matter.
• Potential generic competition despite low expected market volume.
• Continued brand value based on supply continuity and institutional familiarity.

Are there Paragraph IV challenges to Virazole?

A Paragraph IV challenge is legally possible if an applicant files an ANDA referencing Virazole and certifies that listed patents are invalid, unenforceable, or not infringed. No widely reported, commercially material Paragraph IV litigation involving Virazole is apparent in the public record.

The absence of prominent Paragraph IV litigation is consistent with the product’s narrow market. A generic applicant would face limited revenue potential, specialized manufacturing requirements, and uncertain hospital demand. Those conditions reduce the economic return from patent litigation.

Paragraph IV factor	Virazole assessment
Patent target	No material active patent barrier publicly established
Litigation visibility	No major widely reported case identified
Entry incentive	Low to moderate, depending on supply and pricing
Likely commercial strategy	Low-cost niche entry or hospital-contract supply
Launch risk	Limited market volume and specialized administration

What formulations are protected by Virazole-related patents?

The commercially relevant formulation is ribavirin powder reconstituted into an inhalation solution for aerosol delivery. The original product design and delivery method are old. No current formulation patent is broadly recognized as protecting the Virazole franchise.

Potentially protectable areas could include:

• Improved powder stability.
• Alternative reconstitution systems.
• Closed-system aerosol delivery.
• Reduced occupational exposure.
• New nebulizer compatibility.
• Ready-to-use liquid presentations.
• Modified dosing or administration protocols.

These potential innovations would require separate patent filings and FDA review. They would not automatically extend protection for the original Virazole product.

What is the financial trajectory of Virazole?

Public financial data do not provide a standalone Virazole revenue series. Bausch Health reports revenue by business segment and product group, but Virazole is not normally reported as a separate material line item. [2]

The product’s financial trajectory is best characterized as a mature, low-volume hospital franchise with possible price resilience but declining structural demand.

Financial driver	Directional impact
Narrow pediatric indication	Limits total units
Hospital-only use	Concentrates sales among institutional buyers
Specialized delivery equipment	Raises operational complexity
Lack of routine guideline support	Depresses utilization
Generic availability risk	Pressures price and share
Limited alternative inhaled products	Supports continuity of demand
RSV prevention expansion	Reduces severe cases eligible for treatment
Seasonal outbreaks	Creates episodic volume spikes
Manufacturing concentration	Can support pricing if supply is constrained

Does Virazole generate material revenue for Bausch Health?

Virazole is unlikely to be a material contributor to Bausch Health’s consolidated revenue relative to the company’s major brands and businesses. The product may still produce attractive gross margins if manufacturing costs are controlled and pricing reflects its specialized hospital use. That does not imply substantial enterprise-level revenue.

The product’s economics are more relevant at the SKU and portfolio level:

• A small number of annual treatment courses can support a niche product.
• Hospital procurement may favor an established supplier during RSV surges.
• Low volumes increase the risk that manufacturing or quality events materially affect availability.
• Price increases may improve revenue per unit but accelerate generic substitution and formulary scrutiny.
• A competitor with reliable supply could capture share without needing superior clinical efficacy.

What patent litigation affects Virazole?

No major ongoing patent litigation is publicly established as a central commercial issue for Virazole. The principal legal risks are more likely to involve product liability, labeling, supply, regulatory compliance, or procurement disputes than infringement litigation.

The absence of visible patent litigation reflects the product’s mature status. There is limited value in defending expired patents, and the market does not appear large enough to support repeated originator-generic litigation.

What generic launch scenarios exist for Virazole?

Three generic-entry scenarios are commercially plausible.

Scenario 1: No meaningful generic entry

The market remains too small for a manufacturer to justify development, validation, regulatory filing, and specialized supply arrangements. Virazole retains most institutional business despite the absence of patent protection.

Scenario 2: Single generic entrant

A single ANDA-approved product enters during or before an RSV season. The entrant competes mainly on price and supply reliability. Virazole retains hospitals that prioritize established procurement and delivery-system familiarity.

Scenario 3: Multiple generic entrants

Several suppliers enter after a successful first launch. Pricing declines, hospital tenders become more competitive, and the branded product becomes a backup or premium-supply option. This scenario requires enough demand and manufacturing capacity to support more than one supplier.

The most likely near-term outcome is limited generic pressure rather than a rapid, high-volume generic conversion. The market is operationally difficult and clinically narrow, but a supply disruption or sharp price increase could improve the entry case.

How does Virazole compare with newer RSV products?

Virazole treats established severe infection. Nirsevimab and maternal vaccination prevent disease. The products occupy different points in the care pathway, but preventive uptake can reduce the addressable treatment pool for Virazole.

Product	Company	Role	Effect on Virazole
Virazole	Bausch Health-associated commercialization	Treatment of severe hospitalized RSV	Reference product
Beyfortus	Sanofi/AstraZeneca	Long-acting infant RSV prevention	Reduces severe disease incidence
Abrysvo	Pfizer	Maternal RSV vaccination and other approved uses	Reduces infant RSV risk through maternal immunization
Arexvy	GSK	Older-adult RSV prevention	Minimal direct effect on pediatric Virazole demand
Supportive care	Hospitals	Standard management for many cases	Primary volume constraint

What geographic markets support Virazole?

The strongest commercial relevance is in the United States, where Virazole has FDA approval and established hospital use. International markets may rely on locally registered ribavirin products, hospital-compounded preparations, or alternative treatment protocols. Geographic revenue is difficult to quantify because public filings do not break out Virazole sales by country.

The product’s addressable market is concentrated in jurisdictions with:

• Pediatric intensive-care capacity.
• RSV diagnostic infrastructure.
• Access to aerosol delivery equipment.
• Hospital reimbursement for high-complexity respiratory care.
• Clinical protocols permitting selective ribavirin use.

How strong is the Virazole patent estate?

Virazole has a weak current patent estate but a potentially durable operational position. Its commercial defensibility depends on supply, regulatory compliance, institutional familiarity, and the lack of a large addressable market for competitors.

Patent strength: low.
Regulatory exclusivity: expired.
Manufacturing barrier: moderate.
Brand durability: moderate in selected hospitals.
Long-term growth potential: low.
Generic-entry exposure: moderate, with timing dependent on economics.

Key Takeaways

• Virazole is inhaled ribavirin for severe RSV infection in hospitalized infants and young children.
• The product has no meaningful current patent or regulatory exclusivity.
• No prominent Paragraph IV challenge or major patent litigation is publicly associated with the product.
• Virazole revenue is not separately disclosed by Bausch Health, preventing a reliable standalone sales estimate.
• Demand is constrained by selective clinical use, specialized aerosol delivery, and expanded RSV prevention.
• The product may remain commercially viable as a niche hospital therapy despite low market volume.
• Generic entry is possible, but the small market and manufacturing complexity reduce the incentive for multiple competitors.
• The key business risks are declining utilization, preventive RSV products, supply concentration, and hospital price pressure.

FAQs About Virazole Market and Patent Risk

Is Virazole still FDA approved?

Yes. Virazole remains associated with FDA-approved ribavirin inhalation therapy for severe RSV lower-respiratory-tract infection in hospitalized infants and young children. [1]

Is Virazole the same as oral ribavirin?

No. Both products contain ribavirin, but Virazole is an aerosolized inhalation formulation with a specialized delivery system. Oral ribavirin does not provide an automatic substitute for the approved inhaled product.

Can a generic company launch ribavirin inhalation solution?

Yes, subject to FDA approval and applicable regulatory requirements. The main obstacles are limited market size, specialized manufacturing, delivery-system compatibility, and uncertain hospital demand.

Does nirsevimab replace Virazole?

No. Nirsevimab prevents RSV disease in eligible infants and children; Virazole is used to treat severe established infection. Nirsevimab can reduce the number of patients who progress to a condition in which Virazole might be considered.

Is Virazole a significant revenue product for Bausch Health?

Public filings do not identify Virazole as a separately material revenue driver. Its financial importance is more likely concentrated in niche product profitability and portfolio coverage than in consolidated company sales.

References

1. U.S. Food and Drug Administration. (n.d.). Virazole (ribavirin for inhalation solution) prescribing information. Drugs@FDA.

2. Bausch Health Companies Inc. (2024). Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934. U.S. Securities and Exchange Commission.

3. American Academy of Pediatrics. (2021). Red Book: 2021-2024 report of the Committee on Infectious Diseases (32nd ed.). American Academy of Pediatrics.

4. U.S. Food and Drug Administration. (2023). FDA approves new drug to prevent respiratory syncytial virus disease in infants and young children. FDA.

5. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, 44th ed. FDA.