Pfizer Korea to Launch RSV Vaccine ‘Abrysvo’ for Adults & Pregnant Women in Korea – Eligibility Updates

Pfizer’s RSV Vaccine ‘Abrysvo’ Poised for Expanded Access, Targeting Pregnant Women and Infants

The global race to protect vulnerable populations from respiratory syncytial virus (RSV) is intensifying, with Pfizer’s Abrysvo vaccine nearing potential approval for use in pregnant women, a strategy aimed at bolstering immunity in newborns. This development, alongside increasing RSV vaccination rates in older adults, signals a significant shift in public health approaches to combatting the common, yet potentially serious, respiratory illness. The potential for expanded use of Abrysvo, particularly in protecting infants, is drawing considerable attention from healthcare professionals and pharmaceutical companies alike.

RSV is a common respiratory virus that usually causes mild, cold-like symptoms. However, it can be severe in infants and older adults, leading to bronchiolitis and pneumonia. The virus is highly contagious and spreads through close contact, making it a significant concern during the fall and winter months. Recent increases in RSV cases have underscored the necessitate for effective preventative measures, driving demand for new vaccines and therapies. The World Health Organization estimates that RSV causes approximately 33 million cases of acute lower respiratory infections each year in children under five, resulting in an estimated 3 to 6 million cases requiring hospitalization.

Pfizer Submits Application for Expanded Use in South Korea

According to reports, Korean Pfizer has submitted an application to the Ministry of Food and Drug Safety (MFDS) for approval of Abrysvo for use in both adults and pregnant women. Hit News reports that industry observers anticipate a decision from the MFDS potentially as early as the first half of 2026. This potential approval would mark a significant expansion of the vaccine’s availability, building on its existing approvals for older adults. The company is hoping that broadening the target demographic will enhance the vaccine’s competitive edge in the emerging RSV market.

Abrysvo is a bivalent vaccine, meaning it targets the two main subtypes of RSV, RSV-A and RSV-B. It is designed to prevent lower respiratory tract disease (LRTD) caused by these viruses. The vaccine has already received approval from both the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for use in adults aged 60 years and older, and for vaccination of pregnant individuals to protect their newborns. The FDA approved Abrysvo for the 60+ age group in May 2023, and for pregnant women in August 2023.

Competition Heats Up in the RSV Vaccine Market

Pfizer is not alone in its pursuit of the RSV vaccine market. Moderna is also actively seeking approval for its RSV vaccine, mResve, in South Korea. News1 reports that both Pfizer and Moderna are accelerating their efforts to launch their respective vaccines in the country, anticipating a growing demand for RSV prevention. This competition is expected to drive innovation and potentially lower costs, making RSV vaccines more accessible to a wider population.

Moderna’s mResve received FDA approval in June 2023. The company leverages its messenger RNA (mRNA) technology, which gained prominence during the COVID-19 pandemic, to develop its RSV vaccine. The success of mRNA vaccines against COVID-19 has generated significant interest in the potential of this platform for other infectious diseases, including RSV. Moderna is banking on the established safety and efficacy profile of its mRNA technology to gain traction in the RSV vaccine market, particularly among older adults.

Currently, the first RSV vaccine available in the domestic market is Arexvy, developed by GSK. Arexvy is currently approved for use in individuals aged 60 years and older and has seen rapid adoption since its launch, reflecting the significant need for RSV prevention in this age group. The availability of multiple vaccines is expected to further expand access and coverage, ultimately reducing the burden of RSV-related illness.

Abrysvo Demonstrates Immunogenicity in Immunocompromised Adults

Recent research presented by Pfizer highlights the potential benefits of Abrysvo for individuals with weakened immune systems. Health Chosun reports that a Phase 3 clinical trial, known as MONeT, demonstrated that Abrysvo elicited a robust immune response in immunocompromised adults at risk of severe RSV-related lower respiratory tract disease (LRTD). This is particularly important as these individuals are often at higher risk of complications from RSV infection.

The MONeT sub-study B evaluated the safety and immunogenicity of Abrysvo in four groups of immunocompromised adults: patients with non-small cell lung cancer, those undergoing hemodialysis due to end-stage renal disease, individuals receiving active immunomodulatory therapy for autoimmune inflammatory diseases, and solid organ transplant recipients. The study found that Abrysvo was well-tolerated and induced a strong neutralizing antibody response against RSV-A and RSV-B, comparable to results observed in individuals with healthy immune systems. The 120μg dose of Abrysvo administered in a two-dose regimen demonstrated a potent neutralizing response.

Understanding RSV and its Impact

RSV is a leading cause of lower respiratory tract infections in young children and older adults. Symptoms can range from mild cold-like symptoms to severe bronchiolitis and pneumonia. Infants are particularly vulnerable to severe RSV infection since their airways are smaller and their immune systems are not fully developed. Older adults are also at increased risk due to age-related decline in immune function and the presence of underlying medical conditions.

The virus spreads easily through close contact with infected individuals, such as coughing, sneezing, or touching contaminated surfaces. There is currently no specific treatment for RSV infection, so prevention is key. Good hygiene practices, such as frequent handwashing and covering coughs and sneezes, can help reduce the spread of the virus.

Looking Ahead: Expanding RSV Prevention Strategies

The anticipated approval of Abrysvo for use in pregnant women represents a significant advancement in RSV prevention. By vaccinating pregnant individuals, antibodies are transferred to the fetus, providing passive immunity to the newborn during the first few months of life, when they are most vulnerable to severe RSV infection. This strategy has proven effective for other respiratory viruses, such as influenza.

The ongoing competition between Pfizer, Moderna, and GSK is expected to drive further innovation in RSV vaccine development. Researchers are exploring new vaccine platforms and strategies to improve efficacy and durability of protection. The ultimate goal is to develop a comprehensive RSV prevention strategy that protects all vulnerable populations, including infants, young children, older adults, and individuals with underlying medical conditions. Pfizer plans to share detailed research results at upcoming academic conferences and submit data to regulatory agencies for further review.

The next key milestone will be the decision from the South Korean Ministry of Food and Drug Safety regarding the approval of Abrysvo for expanded use. This decision is expected in the first half of 2026 and will pave the way for wider access to this potentially life-saving vaccine. Stay tuned to World Today Journal for further updates on this developing story.

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