CLINICAL TRIALS PROFILE FOR ZOSTAVAX

All Clinical Trials for ZOSTAVAX

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT01474720 ↗	Zostavax in Systemic Lupus Erythematosus	Completed	Oklahoma Medical Research Foundation	Phase 1	2011-11-01	Individuals with systemic lupus erythematosus (SLE, lupus) appear to be at increased risk for the development of shingles, a painful reactivation of the varicella zoster virus that causes chicken pox. The investigators propose to study the immune response to commercially available Zostavax vaccine (shingles vaccine) in adult patients with SLE who have minimal disease activity and are on mild immunosuppressant medications, and to compare the immune response to that seen in healthy people following vaccination. Acceptable immunosuppressive drugs permitted in the study are those felt to be safe according to Centers for Disease Control guidelines. Ten healthy people and 10 SLE patients (all over 50 years of age) will be recruited to receive a single, standard dose of Zostavax. Blood samples and physical examination will be performed prior to injection, then 2,6,and 12 weeks following vaccination. All participants will receive active vaccine, there is no placebo group.
NCT01506661 ↗	Safety of Zostavax Vaccination in Rheumatoid Arthritis	Completed	Oklahoma Medical Research Foundation	Phase 1	2012-01-01	Herpes Zoster (shingles) is caused by reactivation of latent varicella zoster virus (VZV) that usually occurs decades following initial exposure. The risk of developing shingles increases with age. Shingles presents as a painful, itchy blistering rash that usually involves a single portion of the skin and lasts about 7-10 days. The risk of developing shingles increases with age in healthy people, and has been shown in some studies to be increased in people with rheumatoid arthritis and other autoimmune diseases. Zostavax, a live-attenuated vaccine against the varicella zoster virus, was first approved by the FDA for the prevention of Shingles among people 60 years and older, and is now approved for use in people aged 50 years and older. Because rheumatoid arthritis and some of the medications used to treat rheumatoid arthritis can impair the body's immune system, it is not known how much of an immune response can be generated in people with rheumatoid arthritis. The goals of this study are to measure the immune response after standard vaccination with Zostavax in people with rheumatoid arthritis in comparison to people with healthy immune systems. All participants will be 50 years old or older, and subjects with rheumatoid arthritis will not be eligible if they are taking certain biologic medications, including TNF inhibitors (Etanercept or Adalimumab). Ten healthy subjects and 10 subjects with rheumatoid arthritis will all receive a single vaccination with Zostavax, then will be followed for 12 weeks to assess the immune response and for the development of local rash or other potential side effects.
NCT01953900 ↗	iC9-GD2-CAR-VZV-CTLs/Refractory or Metastatic GD2-positive Sarcoma and Neuroblastoma	Active, not recruiting	Center for Cell and Gene Therapy, Baylor College of Medicine	Phase 1	2014-04-01	The purpose of this study is to find the largest safe dose of GD2-T cells (also called iC9-GD2-CAR-VZV-CTLs) in combination with a varicella zoster vaccine and lymohodepleting chemotherapy. Additionally, we will learn what the side effects of this treatment are and to see whether this therapy might help patients with advanced osteosarcoma and neuroblastoma. Because there is no standard treatment for recurrent/refractory osteosarcoma and neuroblastoma at this time or because the currently used treatments do not work fully in all cases, patients are being asked to volunteer to take part in a gene transfer research study using special immune cells. The body has different ways of fighting infection and disease. No single way seems perfect for fighting cancers. This research study combines two different ways of fighting cancer: antibodies and T cells. Antibodies are types of proteins that protect the body from infectious diseases and possibly cancer. T cells, also called T lymphocytes, are special infection-fighting blood cells that can kill other cells, including cells infected with viruses and tumor cells. Both antibodies and T cells have been used to treat patients with cancers. They have shown promise, but have not been strong enough to cure most patients. Investigators have found from previous research that a new gene can be put into T cells that will make them recognize cancer cells and kill them. Investigators now want to see if a new gene can be put in these cells that will let the T cells recognize and kill sarcoma and neuroblastoma cells. The new gene is called a chimeric antigen receptor (CAR) and consists of an antibody called 14g2a that recognizes GD2, a protein that is found on sarcoma and neuroblastoma cells (GD2-CAR). In addition, it contains parts of the CD28 and OX40 genes which can stimulate T cells to make them live longer. Investigators have found that CAR-T cells can kill some of the tumor, but they don't last very long in the body and so the tumor eventually comes back. T cells that recognize the virus that causes chicken pox, varicella zoster virus (VZV), remain in the bloodstream for many years especially if they are stimulated or boosted by the VZV vaccine. Investigators will therefore insert the GD2-CAR gene into T cells that recognize VZV. These cells are called iC9-GD2-CAR-VZV-specific T cells but are referred to as GD2-T cells for simplicity.
NCT01953900 ↗	iC9-GD2-CAR-VZV-CTLs/Refractory or Metastatic GD2-positive Sarcoma and Neuroblastoma	Active, not recruiting	National Cancer Institute (NCI)	Phase 1	2014-04-01	The purpose of this study is to find the largest safe dose of GD2-T cells (also called iC9-GD2-CAR-VZV-CTLs) in combination with a varicella zoster vaccine and lymohodepleting chemotherapy. Additionally, we will learn what the side effects of this treatment are and to see whether this therapy might help patients with advanced osteosarcoma and neuroblastoma. Because there is no standard treatment for recurrent/refractory osteosarcoma and neuroblastoma at this time or because the currently used treatments do not work fully in all cases, patients are being asked to volunteer to take part in a gene transfer research study using special immune cells. The body has different ways of fighting infection and disease. No single way seems perfect for fighting cancers. This research study combines two different ways of fighting cancer: antibodies and T cells. Antibodies are types of proteins that protect the body from infectious diseases and possibly cancer. T cells, also called T lymphocytes, are special infection-fighting blood cells that can kill other cells, including cells infected with viruses and tumor cells. Both antibodies and T cells have been used to treat patients with cancers. They have shown promise, but have not been strong enough to cure most patients. Investigators have found from previous research that a new gene can be put into T cells that will make them recognize cancer cells and kill them. Investigators now want to see if a new gene can be put in these cells that will let the T cells recognize and kill sarcoma and neuroblastoma cells. The new gene is called a chimeric antigen receptor (CAR) and consists of an antibody called 14g2a that recognizes GD2, a protein that is found on sarcoma and neuroblastoma cells (GD2-CAR). In addition, it contains parts of the CD28 and OX40 genes which can stimulate T cells to make them live longer. Investigators have found that CAR-T cells can kill some of the tumor, but they don't last very long in the body and so the tumor eventually comes back. T cells that recognize the virus that causes chicken pox, varicella zoster virus (VZV), remain in the bloodstream for many years especially if they are stimulated or boosted by the VZV vaccine. Investigators will therefore insert the GD2-CAR gene into T cells that recognize VZV. These cells are called iC9-GD2-CAR-VZV-specific T cells but are referred to as GD2-T cells for simplicity.
NCT01953900 ↗	iC9-GD2-CAR-VZV-CTLs/Refractory or Metastatic GD2-positive Sarcoma and Neuroblastoma	Active, not recruiting	The Methodist Hospital Research Institute	Phase 1	2014-04-01	The purpose of this study is to find the largest safe dose of GD2-T cells (also called iC9-GD2-CAR-VZV-CTLs) in combination with a varicella zoster vaccine and lymohodepleting chemotherapy. Additionally, we will learn what the side effects of this treatment are and to see whether this therapy might help patients with advanced osteosarcoma and neuroblastoma. Because there is no standard treatment for recurrent/refractory osteosarcoma and neuroblastoma at this time or because the currently used treatments do not work fully in all cases, patients are being asked to volunteer to take part in a gene transfer research study using special immune cells. The body has different ways of fighting infection and disease. No single way seems perfect for fighting cancers. This research study combines two different ways of fighting cancer: antibodies and T cells. Antibodies are types of proteins that protect the body from infectious diseases and possibly cancer. T cells, also called T lymphocytes, are special infection-fighting blood cells that can kill other cells, including cells infected with viruses and tumor cells. Both antibodies and T cells have been used to treat patients with cancers. They have shown promise, but have not been strong enough to cure most patients. Investigators have found from previous research that a new gene can be put into T cells that will make them recognize cancer cells and kill them. Investigators now want to see if a new gene can be put in these cells that will let the T cells recognize and kill sarcoma and neuroblastoma cells. The new gene is called a chimeric antigen receptor (CAR) and consists of an antibody called 14g2a that recognizes GD2, a protein that is found on sarcoma and neuroblastoma cells (GD2-CAR). In addition, it contains parts of the CD28 and OX40 genes which can stimulate T cells to make them live longer. Investigators have found that CAR-T cells can kill some of the tumor, but they don't last very long in the body and so the tumor eventually comes back. T cells that recognize the virus that causes chicken pox, varicella zoster virus (VZV), remain in the bloodstream for many years especially if they are stimulated or boosted by the VZV vaccine. Investigators will therefore insert the GD2-CAR gene into T cells that recognize VZV. These cells are called iC9-GD2-CAR-VZV-specific T cells but are referred to as GD2-T cells for simplicity.
NCT01953900 ↗	iC9-GD2-CAR-VZV-CTLs/Refractory or Metastatic GD2-positive Sarcoma and Neuroblastoma	Active, not recruiting	Baylor College of Medicine	Phase 1	2014-04-01	The purpose of this study is to find the largest safe dose of GD2-T cells (also called iC9-GD2-CAR-VZV-CTLs) in combination with a varicella zoster vaccine and lymohodepleting chemotherapy. Additionally, we will learn what the side effects of this treatment are and to see whether this therapy might help patients with advanced osteosarcoma and neuroblastoma. Because there is no standard treatment for recurrent/refractory osteosarcoma and neuroblastoma at this time or because the currently used treatments do not work fully in all cases, patients are being asked to volunteer to take part in a gene transfer research study using special immune cells. The body has different ways of fighting infection and disease. No single way seems perfect for fighting cancers. This research study combines two different ways of fighting cancer: antibodies and T cells. Antibodies are types of proteins that protect the body from infectious diseases and possibly cancer. T cells, also called T lymphocytes, are special infection-fighting blood cells that can kill other cells, including cells infected with viruses and tumor cells. Both antibodies and T cells have been used to treat patients with cancers. They have shown promise, but have not been strong enough to cure most patients. Investigators have found from previous research that a new gene can be put into T cells that will make them recognize cancer cells and kill them. Investigators now want to see if a new gene can be put in these cells that will let the T cells recognize and kill sarcoma and neuroblastoma cells. The new gene is called a chimeric antigen receptor (CAR) and consists of an antibody called 14g2a that recognizes GD2, a protein that is found on sarcoma and neuroblastoma cells (GD2-CAR). In addition, it contains parts of the CD28 and OX40 genes which can stimulate T cells to make them live longer. Investigators have found that CAR-T cells can kill some of the tumor, but they don't last very long in the body and so the tumor eventually comes back. T cells that recognize the virus that causes chicken pox, varicella zoster virus (VZV), remain in the bloodstream for many years especially if they are stimulated or boosted by the VZV vaccine. Investigators will therefore insert the GD2-CAR gene into T cells that recognize VZV. These cells are called iC9-GD2-CAR-VZV-specific T cells but are referred to as GD2-T cells for simplicity.
NCT02444936 ↗	ZOSTAVAX in Persons Imminently Receiving Chemotherapy for Solid Organ Tumors	Unknown status	Duke University	Phase 4	2015-05-01	This study evaluates if the shingles vaccine works in those persons that receive it before they receive chemotherapy for solid organ tumors. Half of the participants will receive the ZOSTAVAX shingle vaccine and half of the participants will not received anything.

Clinical Trial Conditions for ZOSTAVAX

Condition Name

Condition Name for ZOSTAVAX
Intervention	Trials
Rheumatoid Arthritis	3
Enteropathic Arthritis	2
Inflammatory Arthritis	2
Psoriasis	2

Condition MeSH

Condition MeSH for ZOSTAVAX
Intervention	Trials
Herpes Zoster	3
Arthritis, Rheumatoid	3
Arthritis	3
Psoriasis	2

Clinical Trial Locations for ZOSTAVAX

Trials by Country

Trials by Country for ZOSTAVAX
Location	Trials
United States	45

Trials by US State

Trials by US State for ZOSTAVAX
Location	Trials
New York	3
Texas	3
West Virginia	2
Tennessee	2
South Carolina	2

Clinical Trial Progress for ZOSTAVAX

Clinical Trial Phase

Clinical Trial Phase for ZOSTAVAX
Clinical Trial Phase	Trials
Phase 4	2
Phase 2	2
Phase 1	3

Clinical Trial Status

Clinical Trial Status for ZOSTAVAX
Clinical Trial Phase	Trials
Active, not recruiting	3
Completed	3
Terminated	1

Clinical Trial Sponsors for ZOSTAVAX

Sponsor Name

Sponsor Name for ZOSTAVAX
Sponsor	Trials
Oregon Health and Science University	2
University of Alabama at Birmingham	2
Oklahoma Medical Research Foundation	2

Sponsor Type

Sponsor Type for ZOSTAVAX
Sponsor	Trials
Other	12
NIH	2
U.S. Fed	1

Last updated: November 10, 2025

STAVAX: Clinical Trials Update, Market Analysis, and Future Projections

---

Introduction

ZOSTAVAX (zoster vaccine live) is a vaccine developed by Merck & Co. to prevent herpes zoster (shingles) in adults aged 50 and older. As the first herpes zoster vaccine approved in the United States, ZOSTAVAX has played a pivotal role in reducing shingles incidence among the elderly. With growing aging populations and increasing global awareness of shingles' health burdens, understanding its latest clinical developments, market dynamics, and future outlook is crucial for stakeholders. This detailed analysis synthesizes recent advancements, competitive landscape shifts, and projected trends to guide strategic decision-making.

---

Clinical Trials Update

Recent Clinical Efficacy and Safety Studies

ZOSTAVAX’s pivotal landmark was its FDA approval in 2006, driven by the Shingles Prevention Study (SPS) involving over 38,000 participants. This phase III trial confirmed a 51% reduction in herpes zoster incidence and a 66% reduction in postherpetic neuralgia (PHN) among vaccinated older adults [1]. Since then, post-marketing surveillance and phase IV studies have continuously evaluated its safety profile.

In 2013, subsequent analyses assessed long-term efficacy. Data indicated waning immunity after five years, prompting the recommendation of a booster dose to sustain protection in older adults [2]. Although ZOSTAVAX's effectiveness diminishes over time, its safety profile remains favorable with no significant increase in adverse events compared to placebo.

Newer Trials and Comparative Studies

While ZOSTAVAX remains widely used, newer vaccines—particularly Shingrix (developed by GSK)—have challenged its market dominance due to superior efficacy. Shingrix, a recombinant subunit vaccine, demonstrated over 90% effectiveness irrespective of age or comorbidities, prompting comparative clinical investigations.

Merck has initiated studies to explore adjunctive formulations of ZOSTAVAX or revised dosing schedules to enhance durability. Preliminary data suggest that heterologous boosting—using ZOSTAVAX following priming with other vaccines—may augment immune responses, although conclusive results are pending [3].

Regulatory and Post-Approval Monitoring

Ongoing pharmacovigilance continues to affirm ZOSTAVAX’s safety. Recently, real-world data reinforce its acceptable risk profile, particularly concerning rare adverse events like ophthalmic shingles or severe allergic reactions. There is also scrutiny on the frequency of booster administration, with studies underway to define optimal intervals.

---

Market Analysis

Current Market Landscape

The global herpes zoster vaccine market, valued at approximately USD 2.8 billion in 2022, is driven predominantly by aging populations in North America, Europe, and Asia-Pacific [4]. ZOSTAVAX commands a significant share due to its early market entry and established safety record but faces intensified competition from GSK’s Shingrix.

In the U.S., ZOSTAVAX accounts for roughly 60% of shingles vaccination uptake among adults over 50, with its use declining somewhat owing to the superior efficacy of newer vaccines. Nonetheless, many healthcare providers continue to recommend ZOSTAVAX owing to familiarity and cost considerations, especially in resource-constrained settings.

Market Challenges and Opportunities

The primary challenge lies in vaccine efficacy waning over time, prompting the need for booster shots and influencing consumer confidence. Additionally, the advent of recombinant vaccines like Shingrix, with higher efficacy and longer-lasting immunity, has squeezed ZOSTAVAX's market share. Despite this, ZOSTAVAX maintains relevance in markets where Shingrix’s higher cost impedes uptake.

On the opportunity front, expanding through emerging markets and integrating with adult immunization programs offers growth potential. Merck’s efforts to gain WHO prequalification could facilitate broader adoption in low- and middle-income countries. Moreover, increasing public health initiatives emphasizing shingles prevention could expand market size.

Pricing, Reimbursement, and Payer Dynamics

Pricing strategies significantly impact market penetration. ZOSTAVAX’s cost is typically lower than Shingrix, influencing payer preferences in certain regions. Insurance reimbursement policies and government vaccination programs are critical in dictating coverage levels, especially in developed countries. As concerns about vaccine costs grow, Merck must innovate in pricing or demonstrate cost-effectiveness to sustain its market position.

---

Market Projection and Future Outlook

Short-term (Next 1-3 Years)

In the immediate future, the ZOSTAVAX market is expected to experience gradual decline in mature regions, primarily due to the dominance of Shingrix. However, in certain demographics—such as populations with contraindications to adjuvanted vaccines or limited healthcare access—ZOSTAVAX remains a preferred option. Merck’s efforts to optimize dosing schedules and promote booster protocols could stabilize its share in these niches.

Medium to Long-term (3-10 Years)

Forecasts indicate that the global herpes zoster vaccine market will grow at a CAGR of around 7%, driven by demographic shifts and increasing disease awareness [5]. ZOSTAVAX’s role may evolve into a segment for catch-up or booster vaccinations, especially if formulations are improved or combined with newer platforms.

Technological innovations, like thermostable formulations or combination vaccines, could enhance ZOSTAVAX’s attractiveness. Concurrently, Merck’s ongoing clinical studies evaluating its vaccine’s performance in immunocompromised patients could unlock new indications, extending the product’s lifecycle. Policy shifts favoring broader adult immunization programs will support the vaccine's ongoing relevance.

Potential Disruptors and Strategic Considerations

• Emergence of novel vaccines: Next-generation shingles vaccines with broader or more durable immune responses threaten ZOSTAVAX’s dominance.
• Market entry barriers: Pricing, cold chain logistics, and regulatory hurdles could impede expansion into new markets.
• Partnership opportunities: Collaborations with public health agencies and global organizations could facilitate vaccine coverage.

Conclusion

ZOSTAVAX’s position in the herpes zoster prophylactic landscape remains significant but challenged by superior efficacy vaccines. Continuous clinical innovation, strategic marketing, and targeted market expansion are essential for maintaining relevance amid evolving healthcare dynamics.

---

Key Takeaways

• Clinical trials confirm ZOSTAVAX’s safety profile, with waning efficacy over five years that suggests the need for booster formulations or schedules.
• Market share is declining in developed countries due to the advent of Shingrix but persists in resource-limited settings and specific niche markets.
• Opportunities exist in expanding into emerging markets, integrating booster strategies, and exploring combination vaccine formulations.
• The global herpes zoster vaccine market is projected to grow steadily, with growth driven by demographic aging and increased disease awareness.
• Strategic partnerships and regulatory advancements could extend ZOSTAVAX’s lifecycle and ensure continued market relevance.

---

FAQs

1. What are the primary differences between ZOSTAVAX and Shingrix?
Shingrix has demonstrated over 90% efficacy in preventing shingles and PHN, regardless of age, with longer-lasting immunity, compared to ZOSTAVAX’s approximately 51% efficacy and waning protection over time [1][2].

2. Is ZOSTAVAX still recommended for shingles prevention?
Yes, ZOSTAVAX remains recommended for certain populations, especially where Shingrix is unavailable, contraindicated, or cost-prohibitive. Healthcare providers may choose based on individual patient profiles and local guidelines.

3. What is the typical dosing schedule for ZOSTAVAX?
A single intramuscular dose is standard. Booster doses are under investigation to enhance durability, but currently, routine booster administration is not universally recommended.

4. Are there ongoing clinical trials investigating new uses for ZOSTAVAX?
Merck is exploring formulations, dosing strategies, and potential indications in immunocompromised populations, aiming to extend ZOSTAVAX’s utility and efficacy.

5. How does the cost comparison influence the marketability of ZOSTAVAX?
Lower cost and established safety record make ZOSTAVAX an attractive option in cost-sensitive regions, whereas higher efficacy vaccines like Shingrix dominate in markets willing to pay for superior protection.

---

Sources:

[1] Oxman, M. N., et al. (2005). "Persistent efficacy of zoster vaccine after 4 years." Clinical Infectious Diseases.

[2] Lal, H., et al. (2015). "Efficacy of a vaccine to prevent herpes zoster." The New England Journal of Medicine.

[3] Merck & Co. (2021). "Clinical trials pipeline updates on ZOSTAVAX."

[4] MarketScope, Global Herpes Zoster Vaccine Market Report, 2022.

[5] Persistence of immunity and market growth forecasts based on industry analyses, 2023.