mRESVIA: Uses, Dosage & Side Effects
An mRNA-based vaccine for the prevention of RSV lower respiratory tract disease in adults aged 60 and older and at-risk adults aged 18–59
mRESVIA is a nucleoside-modified messenger RNA (mRNA) vaccine developed by Moderna for the prevention of lower respiratory tract disease caused by respiratory syncytial virus (RSV) in adults aged 60 years and older, and in adults aged 18 to 59 years who are at increased risk for RSV disease. The vaccine contains mRNA encoding the RSV prefusion F glycoprotein, encapsulated in lipid nanoparticles. After intramuscular injection, the mRNA instructs host cells to produce the prefusion F protein, which triggers the immune system to generate protective antibodies and cellular immune responses against RSV. mRESVIA is the first mRNA-based RSV vaccine authorized worldwide, representing a significant advancement in the prevention of a virus responsible for substantial morbidity and mortality in older adults each year.
Quick Facts: mRESVIA
Key Takeaways
- mRESVIA is the world's first mRNA-based vaccine against respiratory syncytial virus (RSV), approved for adults aged 60 years and older and at-risk adults aged 18–59 to help prevent RSV-associated lower respiratory tract disease.
- The vaccine is given as a single intramuscular injection (0.5 mL containing 50 micrograms of mRNA) in the deltoid muscle by a healthcare professional, with no established booster schedule at this time.
- In the pivotal ConquerRSV phase III trial, mRESVIA demonstrated 83.7% efficacy against RSV-associated lower respiratory tract disease with at least two symptoms, with robust protection against both RSV-A and RSV-B subtypes.
- Common side effects include injection site pain, fatigue, headache, muscle pain, joint pain, and swollen lymph nodes—most are mild to moderate and resolve within a few days.
- mRESVIA can be co-administered with influenza or COVID-19 vaccines and should be stored frozen at −40°C to −15°C, with a 30-day shelf life when thawed and refrigerated at 2–8°C.
What Is mRESVIA and What Is It Used For?
mRESVIA contains a nucleoside-modified single-stranded messenger RNA (mRNA) with a 5′-cap structure that encodes the respiratory syncytial virus (RSV) glycoprotein F, stabilized in its prefusion conformation. This mRNA is encapsulated within lipid nanoparticles (LNPs), which serve as a delivery system to protect the fragile mRNA molecule and facilitate its uptake into human cells after injection. The lipid nanoparticle formulation includes SM-102, cholesterol, DSPC (1,2-distearoyl-sn-glycero-3-phosphocholine), and PEG2000-DMG, which together form a stable particle that can efficiently deliver mRNA to the target cells.
Respiratory syncytial virus (RSV) is one of the most common respiratory viruses worldwide. While RSV infection can occur at any age, it poses a particularly significant threat to older adults and individuals with chronic underlying conditions. RSV typically causes mild, cold-like symptoms in healthy younger adults, including nasal congestion, cough, and sore throat. However, in adults aged 60 and older, RSV can progress to severe lower respiratory tract disease, including bronchiolitis, pneumonia, and acute exacerbations of chronic obstructive pulmonary disease (COPD) or asthma. According to the World Health Organization (WHO), RSV is responsible for approximately 336,000 hospitalizations and 14,000 in-hospital deaths annually among adults aged 60 and older in high-income countries alone. The global burden is substantially higher when low- and middle-income countries are included.
The RSV prefusion F (pre-F) protein is the primary target for neutralizing antibodies against RSV. The F protein exists in two conformational states: the prefusion form (before the virus enters host cells) and the postfusion form (after viral entry). Research has demonstrated that the prefusion conformation is the most potent target for generating neutralizing antibodies, as this is the form that the immune system encounters first during natural infection. The stabilization of the F protein in its prefusion conformation was a critical breakthrough in RSV vaccine development, as previous vaccine candidates targeting the postfusion form had shown limited efficacy.
After intramuscular injection, the lipid nanoparticles deliver the mRNA into host cells at the injection site and in draining lymph nodes. Inside the cell, the mRNA is translated by the host cell's ribosomes to produce the RSV prefusion F glycoprotein. This protein is then displayed on the cell surface and secreted, where it is recognized by the immune system. The immune response includes both humoral immunity (production of neutralizing antibodies against the RSV prefusion F protein, targeting both RSV-A and RSV-B subtypes) and cellular immunity (activation of T-cell responses that help coordinate the overall immune defense). If the vaccinated individual subsequently encounters RSV, the immune system can rapidly recognize and neutralize the virus, thereby preventing or reducing the severity of RSV-associated lower respiratory tract disease.
The efficacy of mRESVIA was evaluated in the pivotal ConquerRSV phase II/III clinical trial (NCT05127434), a randomized, double-blind, placebo-controlled study conducted across approximately 22 countries involving over 35,000 adults aged 60 years and older. The primary analysis demonstrated an overall vaccine efficacy of 83.7% (95.88% CI: 66.1–92.2%) against RSV-associated lower respiratory tract disease defined by at least two signs or symptoms (such as new or worsened cough, wheezing, sputum production, shortness of breath, or tachypnea). The vaccine showed robust efficacy against both RSV-A and RSV-B subtypes, and protection was observed regardless of baseline RSV serostatus, age group (60–69, 70–79, and 80+ years), or the presence of underlying comorbidities such as COPD, asthma, diabetes, or chronic heart disease.
mRESVIA was first authorized by the U.S. Food and Drug Administration (FDA) in May 2024 for adults aged 60 and older. The European Medicines Agency (EMA) subsequently granted marketing authorization in the EU. The indication was later expanded in several regulatory jurisdictions to include adults aged 18 to 59 years who are at increased risk for RSV disease, such as those with chronic lung disease, chronic heart disease, immunocompromising conditions, or other risk factors. mRESVIA represents the first mRNA-based RSV vaccine to receive regulatory approval worldwide, joining the protein subunit RSV vaccine Arexvy (GSK) as the second RSV vaccine authorized for older adults.
The mRNA platform used in mRESVIA offers several advantages for vaccine development: rapid manufacturing scalability, the ability to precisely encode the prefusion F protein in its optimal conformation, strong induction of both antibody and T-cell responses, and the potential for rapid adaptation if new RSV variants emerge. Unlike traditional vaccines that use inactivated virus or purified protein, mRNA vaccines instruct the body's own cells to produce the target antigen, which may lead to a more robust and balanced immune response.
What Should You Know Before Receiving mRESVIA?
Contraindications
The primary contraindication for mRESVIA is hypersensitivity (allergy) to the active substance (the mRNA) or to any of the other components of the vaccine. The excipients in mRESVIA include SM-102, cholesterol, DSPC, PEG2000-DMG, tromethamine, tromethamine hydrochloride, acetic acid, sodium acetate trihydrate, sucrose, and water for injections. If you have a known allergy to any of these substances—particularly polyethylene glycol (PEG), which is a component of PEG2000-DMG—you must inform your healthcare provider before vaccination. PEG allergy is rare but has been associated with allergic reactions to mRNA vaccines.
If you have previously experienced a severe allergic reaction (such as anaphylaxis) following any vaccine injection, you should discuss this with your healthcare provider. A history of anaphylaxis to a prior mRNA vaccine (such as a COVID-19 mRNA vaccine) or to a component shared with mRESVIA is a contraindication to receiving this vaccine.
Warnings and Precautions
As with all injectable vaccines, appropriate medical treatment and supervision should always be readily available in case of a rare anaphylactic reaction following administration. Individuals should be observed for at least 15 minutes after vaccination. If you feel faint or dizzy before or after the injection, inform your healthcare provider immediately.
Before receiving mRESVIA, discuss the following with your healthcare provider:
- Severe allergic reactions: If you have ever had a severe allergic reaction after any vaccine injection, including anaphylaxis, inform your healthcare provider. Appropriate medical monitoring should be available for at least 15 minutes after vaccination.
- Bleeding disorders: If you have a bleeding disorder or bruise easily, tell your healthcare provider. As mRESVIA is an intramuscular injection, caution is needed in individuals receiving anticoagulant therapy or those with thrombocytopenia or any coagulation disorder, as bleeding or bruising may occur at the injection site.
- Weakened immune system: If you have a compromised immune system due to disease (such as HIV/AIDS, organ transplant recipients, cancer patients undergoing chemotherapy) or immunosuppressive medications (such as high-dose corticosteroids, biologics, or chemotherapy agents), the immune response to mRESVIA may be reduced. You may not derive full benefit from the vaccine. Nevertheless, vaccination is still recommended for immunocompromised individuals, as they are at higher risk for severe RSV disease.
- Anxiety-related reactions: If you feel nervous about vaccination or have previously fainted after an injection, inform your healthcare provider. Vasovagal reactions (fainting) can occur in association with needle injections and should be managed by sitting or lying down during and after the injection.
- Acute illness with high fever: If you have a current infection with high fever, vaccination should be postponed until recovery. A mild infection, such as a common cold, is generally not a reason to delay vaccination, but consult your healthcare provider.
As with all vaccines, mRESVIA may not provide full protection in every person who receives it. The degree of protection varies among individuals and may be influenced by age, immune status, and the presence of comorbidities.
Children and Adolescents
mRESVIA is not indicated for use in children and adolescents under 18 years of age. The vaccine was specifically developed and studied for use in older adults (60 years and above) and at-risk adults aged 18 to 59. RSV prevention in infants and young children requires different strategies, such as maternal immunization during pregnancy with RSV vaccines specifically designed for that purpose, or the use of monoclonal antibodies like nirsevimab (Beyfortus).
Pregnancy and Breastfeeding
mRESVIA should not be used during pregnancy. The vaccine has not been studied in pregnant women, and the effects on the developing fetus are unknown. If you are pregnant, think you may be pregnant, or are planning to become pregnant, consult your healthcare provider before receiving this vaccine. It is important to note that mRESVIA is not intended as a maternal immunization vaccine—it is designed for older adults and at-risk adults, not for protecting newborns through maternal antibody transfer.
It is not known whether the components of mRESVIA are excreted in human breast milk. If you are breastfeeding, discuss with your healthcare provider whether it is appropriate for you to receive the vaccine, weighing the potential benefits of vaccination against any theoretical risks to the breastfed infant.
Driving and Operating Machinery
Some of the side effects of mRESVIA, such as fatigue and dizziness, may temporarily affect your ability to drive or operate machinery. If you experience these effects after vaccination, wait until they have resolved before driving or operating machinery. These side effects typically resolve within one to three days.
Sodium Content
mRESVIA contains less than 1 mmol (23 mg) of sodium per dose, meaning it is essentially sodium-free. This is relevant for patients on a sodium-restricted diet.
How Does mRESVIA Interact with Other Drugs?
As a vaccine, mRESVIA does not undergo hepatic metabolism via cytochrome P450 (CYP) enzymes and is therefore not expected to interact with most medications through traditional pharmacokinetic drug-drug interaction mechanisms. The mRNA component is translated intracellularly and subsequently degraded by normal cellular processes, while the lipid nanoparticle components are metabolized through standard lipid metabolism pathways.
Clinical studies have evaluated the co-administration of mRESVIA with other commonly administered vaccines in the target population of older adults. The following co-administration data are available:
| Co-administered Vaccine | Study Data | Recommendation |
|---|---|---|
| Influenza vaccine (seasonal) | Studied in clinical trials; acceptable immune response to both vaccines | Can be given at the same time (different injection sites) |
| COVID-19 mRNA vaccine | Studied in clinical trials; acceptable immune response to both vaccines | Can be given at the same time (different injection sites) |
| Pneumococcal vaccine (PCV/PPSV) | Limited data; no formal co-administration studies completed | Consult healthcare provider; can generally be given at different sites |
| Shingles vaccine (recombinant) | No specific co-administration data available | Consult healthcare provider for timing |
When mRESVIA is given simultaneously with other injectable vaccines, each vaccine should be administered at a different injection site (for example, one in each arm). This ensures that local reactions at the injection site can be properly attributed to the correct vaccine and reduces the likelihood of local discomfort from overlapping injection sites.
Immunosuppressive Medications
Patients receiving immunosuppressive therapy—including high-dose systemic corticosteroids, biologic agents (such as TNF inhibitors, B-cell depleting agents like rituximab, or JAK inhibitors), chemotherapy, or antirejection medications for organ transplants—may have a diminished immune response to mRESVIA. The vaccine may still be administered to these individuals, as the potential benefits of vaccination generally outweigh the risks in immunocompromised patients who are at higher risk for severe RSV disease. However, the timing of vaccination relative to immunosuppressive treatment cycles should be discussed with the treating physician to optimize the immune response.
Patients on low-dose corticosteroids, inhaled corticosteroids, or topical corticosteroids are not expected to have a significantly impaired response to mRESVIA and can generally receive the vaccine without concern.
The ability to co-administer mRESVIA with influenza and COVID-19 vaccines is a significant practical benefit, as it allows older adults to receive multiple important vaccinations in a single healthcare visit. This "one-stop" approach can improve vaccination rates, reduce the number of healthcare appointments needed, and increase protection during the respiratory virus season when RSV, influenza, and COVID-19 often co-circulate.
What Is the Correct Dosage of mRESVIA?
mRESVIA is administered by a healthcare professional—such as a doctor, pharmacist, or nurse—using aseptic technique to ensure sterility. The vaccine comes in pre-filled syringes and is ready for use once thawed to the appropriate temperature. The product must not be diluted, and the pre-filled syringe must not be shaken before use.
Adults (60 Years and Older)
Standard Dose
The recommended dose is a single injection of 0.5 mL (containing 50 micrograms of mRNA) administered intramuscularly into the deltoid muscle of the upper arm. The vaccine is given as a one-time injection. In clinical trials, a single dose was sufficient to induce a robust immune response in the majority of participants.
| Patient Group | Dose | Route | Schedule |
|---|---|---|---|
| Adults ≥60 years | 0.5 mL (50 mcg mRNA) | Intramuscular (deltoid) | Single dose |
| At-risk adults 18–59 years | 0.5 mL (50 mcg mRNA) | Intramuscular (deltoid) | Single dose |
| Children <18 years | Not applicable | Not applicable | Not indicated |
At-Risk Adults (18–59 Years)
mRESVIA is also indicated for adults aged 18 to 59 years who are at increased risk of RSV disease. At-risk conditions include chronic lung disease (such as COPD, asthma, interstitial lung disease), chronic heart disease (such as heart failure, coronary artery disease), immunocompromising conditions or immunosuppressive therapy, diabetes mellitus, chronic kidney disease, chronic liver disease, and other conditions that increase susceptibility to severe respiratory infections. The dosing regimen is identical: a single intramuscular injection of 0.5 mL.
Elderly Patients
No dose adjustment is required for elderly patients, including those aged 80 years and older. The ConquerRSV clinical trial included participants across a wide age range (60–80+ years), and vaccine efficacy was maintained across all age subgroups. However, as with any vaccine, the magnitude of the immune response may be somewhat lower in the very elderly compared with younger adults.
Booster Doses
At the time of initial approval, no booster dose schedule has been established for mRESVIA. The duration of protection following a single dose is still being evaluated in ongoing long-term follow-up studies from the ConquerRSV trial. Data on the persistence of immune responses and the potential need for revaccination are being collected and will inform future recommendations regarding booster doses. Your healthcare provider will advise you if and when a booster dose may be recommended based on evolving evidence.
Administration Instructions for Healthcare Professionals
mRESVIA is supplied as a pre-filled syringe containing a white to off-white dispersion. The vaccine may be received in a frozen state or already thawed. If frozen, it must be completely thawed before administration. Thawing can be performed in a refrigerator (2–8°C) or at room temperature (15–25°C). Thawing times depend on the packaging configuration: a single pre-filled syringe requires approximately 100 minutes in a refrigerator or 40 minutes at room temperature. The vaccine must not be refrozen once thawed.
Before administration, inspect the vaccine visually. It should appear as a white to off-white dispersion. Do not administer if the vaccine is discolored or contains foreign particles. Remove the vial cap by twisting counterclockwise, attach a sterile needle (21-gauge or thinner), and administer the full dose intramuscularly. Needles are not included in the packaging.
What Are the Side Effects of mRESVIA?
Like all vaccines, mRESVIA can cause side effects, although not everyone who receives the vaccine will experience them. The safety of mRESVIA was evaluated in the ConquerRSV clinical trial involving over 35,000 participants aged 60 years and older, as well as in additional studies in at-risk adults aged 18–59. The majority of reported adverse events were mild to moderate in intensity, with onset typically within the first few days after vaccination and resolution within one to three days. The following side effects have been reported:
Very Common
May affect more than 1 in 10 people
- Injection site pain or tenderness
- Swollen or tender lymph nodes in the armpit (axillary lymphadenopathy)
- Headache
- Nausea and/or vomiting
- Muscle pain (myalgia)
- Joint pain (arthralgia)
- Fatigue
- Chills
Common
May affect up to 1 in 10 people
- Redness (erythema) at the injection site
- Swelling or hardening (induration) at the injection site
- Fever (pyrexia)
Uncommon
May affect up to 1 in 100 people
- Hypersensitivity (immune system reaction with increased sensitivity or intolerance)
- Dizziness
Rare
May affect up to 1 in 1,000 people
- Bell's palsy (temporary facial weakness or drooping on one side)
- Urticaria (hives, itchy rash)
- Pruritus (itching) at the injection site
The most frequently reported side effects were injection site pain and fatigue, both occurring in a substantial proportion of vaccine recipients. These reactions are consistent with the body mounting an immune response to the vaccine and are similar in nature and frequency to those reported with other mRNA-based vaccines, including COVID-19 mRNA vaccines. The reactogenicity profile of mRESVIA was generally milder in participants aged 75 years and older compared with those aged 60–74 years.
Serious Side Effects
Serious adverse events were reported at similar rates in the mRESVIA and placebo groups in the ConquerRSV trial, suggesting no significant increase in risk of serious side effects attributable to the vaccine. However, as with any vaccine, serious allergic reactions (anaphylaxis) can occur very rarely. Healthcare providers should be prepared to manage anaphylaxis with appropriate medical treatment whenever mRESVIA is administered.
Bell's palsy (temporary facial nerve paralysis causing weakness or drooping on one side of the face) was reported as a rare adverse event. Cases were generally mild to moderate and self-limiting, resolving within weeks to months. The relationship between mRESVIA and Bell's palsy is being monitored through ongoing pharmacovigilance activities.
Reporting Side Effects
It is important to report any suspected side effects after vaccination. Reporting helps regulatory authorities continuously monitor the benefit-risk profile of vaccines. In the United States, suspected adverse events can be reported to the Vaccine Adverse Event Reporting System (VAERS). In the European Union, reports can be made to the national medicines agency of your country. In the United Kingdom, reports can be submitted via the Yellow Card Scheme. Your healthcare provider can assist you with reporting any adverse events.
Contact your healthcare provider if you experience any side effects that are severe, do not resolve within a few days, or concern you. Seek immediate medical attention if you develop signs of a serious allergic reaction, such as difficulty breathing, swelling of the face, lips, tongue, or throat, rapid heartbeat, dizziness, or widespread skin rash shortly after vaccination.
How Should mRESVIA Be Stored?
Storage and handling of mRESVIA are primarily the responsibility of the healthcare provider. The following storage conditions ensure the vaccine maintains its potency and safety:
| Storage Condition | Temperature | Duration | Notes |
|---|---|---|---|
| Long-term (frozen) | −40°C to −15°C | Up to 1 year (shelf life) | Store in original carton; protect from light |
| Refrigerated (thawed) | 2–8°C | Up to 30 days | Mark new expiry date on carton; do not refreeze |
| Room temperature | 8–25°C | Up to 24 hours | After removal from refrigerator; discard if unused |
The pre-filled syringes should be stored in their original carton to protect them from light. When moving the vaccine from frozen storage to refrigerated storage, the outer carton must be relabeled with the new expiry date applicable to the refrigerated shelf life (30 days from the date of thawing). Once the vaccine has been thawed, it must not be refrozen. If received already thawed at 2–8°C, it should remain at that temperature until use.
Thawing can be performed either in a refrigerator (2–8°C) or at room temperature (15–25°C). Thawing times vary depending on the packaging: a single pre-filled syringe requires approximately 100 minutes in a refrigerator or 40 minutes at room temperature. A carton of 10 pre-filled syringes requires approximately 160 minutes in a refrigerator or 80 minutes at room temperature. If thawed at room temperature, the syringes are ready for immediate administration and should not be returned to the refrigerator.
mRESVIA should be kept out of the sight and reach of children. Do not use the vaccine after the expiry date printed on the carton (the last day of the indicated month). Do not use the pre-filled syringe if it has been dropped, damaged, or if the safety seal on the carton has been broken. Unused vaccine and waste material should be disposed of in accordance with local regulations for pharmaceutical waste.
What Does mRESVIA Contain?
Active Ingredient
The active substance in mRESVIA is a single-stranded, nucleoside-modified messenger RNA (mRNA) with a 5′-cap structure. This mRNA encodes the respiratory syncytial virus glycoprotein F, which has been engineered and stabilized in its prefusion conformation. The prefusion F protein is the form that sits on the surface of the RSV virion before the virus fuses with host cells, and it is the primary target for the most potent neutralizing antibodies. Each pre-filled syringe contains 50 micrograms of mRNA in 0.5 mL of solution.
The mRNA is encapsulated within lipid nanoparticles (LNPs), which serve multiple functions: they protect the mRNA from enzymatic degradation in the extracellular environment, facilitate cellular uptake through endocytosis, and promote escape of the mRNA from endosomes into the cytoplasm where it can be translated into protein by the host cell's ribosomes. After the mRNA has been translated, it is naturally degraded by the cell's normal metabolic processes and does not integrate into the host's DNA.
Excipients
The lipid nanoparticle and buffer system contains the following excipients:
- SM-102: A proprietary ionizable lipid (heptadecan-9-yl 8-((2-hydroxyethyl)(6-oxo-6-(undecyloxy)hexyl)amino)octanoate) that is the key functional component of the lipid nanoparticle, facilitating cellular uptake and endosomal escape of the mRNA.
- Cholesterol: Provides structural stability to the lipid nanoparticle membrane.
- DSPC (1,2-distearoyl-sn-glycero-3-phosphocholine): A phospholipid that helps form the outer layer of the lipid nanoparticle.
- PEG2000-DMG (1,2-dimyristoyl-rac-glycero-3-methoxypolyethylene glycol-2000): A PEGylated lipid that provides a hydrophilic shield, preventing aggregation of the nanoparticles and extending their circulation time. Note: individuals with known PEG allergy should discuss this with their healthcare provider.
- Tromethamine (tris) and tromethamine hydrochloride: Buffer components that maintain the pH of the formulation.
- Acetic acid and sodium acetate trihydrate: Additional buffer components for pH stability.
- Sucrose: A cryoprotectant that protects the lipid nanoparticles during freezing and thawing.
- Water for injections: The solvent for the formulation.
Appearance and Packaging
mRESVIA is a white to off-white dispersion for injection (pH 7.0–8.0). It may contain white or translucent product-related particles, which are normal. The vaccine is available in packs containing 1 or 10 pre-filled syringes. Not all pack sizes may be marketed in all countries. Needles are not included in the packaging; a sterile 21-gauge or thinner needle should be used for administration.
The marketing authorization holder is Moderna Biotech Spain, S.L., with registered address at C/ Julián Camarillo nº 31, 28037 Madrid, Spain.
Frequently Asked Questions About mRESVIA
mRESVIA is an mRNA-based vaccine developed by Moderna to prevent lower respiratory tract disease caused by respiratory syncytial virus (RSV). It is indicated for adults aged 60 years and older, as well as adults aged 18 to 59 years who are at increased risk of RSV disease due to underlying conditions such as chronic lung disease, chronic heart disease, immunocompromising conditions, or diabetes. The vaccine is given as a single intramuscular injection by a healthcare professional.
In the pivotal ConquerRSV phase III clinical trial involving over 35,000 adults aged 60 and older, mRESVIA demonstrated 83.7% efficacy against RSV-associated lower respiratory tract disease defined by at least two signs or symptoms. The vaccine was effective against both RSV-A and RSV-B subtypes and showed consistent efficacy across different age groups and in participants with underlying comorbidities. Protection was observed during the first RSV season following vaccination.
Yes, clinical studies have shown that mRESVIA can be safely co-administered with seasonal influenza vaccines and COVID-19 mRNA vaccines. When given together, each vaccine should be injected at a different site (for example, one in each arm). Co-administration allows older adults to receive multiple important vaccinations in a single healthcare visit, which is particularly convenient during the autumn/winter respiratory virus season.
mRESVIA is the first mRNA-based RSV vaccine, while Arexvy (by GSK) is a protein subunit vaccine that contains a recombinant RSV prefusion F protein with an adjuvant (AS01E). Both vaccines target the RSV prefusion F protein, which is the most important target for neutralizing antibodies. The key difference lies in the platform: mRESVIA uses mRNA technology to instruct the body's cells to produce the protein, while Arexvy provides the pre-made protein directly. Both have shown high efficacy in clinical trials. The choice between them may depend on availability, individual patient factors, and healthcare provider recommendation.
At present, no booster dose schedule has been established for mRESVIA. The current recommendation is for a single dose. Long-term follow-up studies from the ConquerRSV trial are ongoing to evaluate the duration of protection and determine whether revaccination will be needed. As more data become available, health authorities such as the CDC, EMA, and WHO will update their recommendations regarding booster doses. Your healthcare provider will keep you informed of any changes to the vaccination schedule.
mRESVIA can be given to immunocompromised individuals, although the immune response may be reduced compared to people with normal immune function. Since mRESVIA is an mRNA vaccine (not a live virus vaccine), it does not pose a risk of causing RSV infection, even in immunocompromised patients. People with weakened immune systems are actually at higher risk for severe RSV disease, which makes vaccination particularly important for this group. Discuss the optimal timing of vaccination with your healthcare provider, especially in relation to immunosuppressive treatment cycles.
References
- European Medicines Agency (EMA). mRESVIA Summary of Product Characteristics. Updated 2025. Available at: EMA – mRESVIA EPAR.
- U.S. Food and Drug Administration (FDA). mRESVIA Prescribing Information. Approved May 2024. Available at: FDA – mRESVIA.
- Wilson E, Goswami J, Baqui AH, et al. Efficacy and Safety of an mRNA-Based RSV Prefusion F Protein Vaccine in Older Adults. New England Journal of Medicine. 2023;389(24):2233-2244. doi:10.1056/NEJMoa2307079.
- Centers for Disease Control and Prevention (CDC). Use of Respiratory Syncytial Virus Vaccines in Older Adults: Recommendations of the Advisory Committee on Immunization Practices — United States, 2023–2024. MMWR. 2023;72(29):793-801.
- World Health Organization (WHO). RSV Vaccines: WHO Position Paper. Weekly Epidemiological Record. 2024;99(13):157-176.
- Falsey AR, Hennessey PA, Formica MA, et al. Respiratory Syncytial Virus Infection in Elderly and High-Risk Adults. New England Journal of Medicine. 2005;352(17):1749-1759. doi:10.1056/NEJMoa043951.
- McLellan JS, Chen M, Leung S, et al. Structure of RSV Fusion Glycoprotein Trimer Bound to a Prefusion-Specific Neutralizing Antibody. Science. 2013;340(6136):1113-1117. doi:10.1126/science.1234914.
- Pardi N, Hogan MJ, Porter FW, Weissman D. mRNA vaccines — a new era in vaccinology. Nature Reviews Drug Discovery. 2018;17(4):261-279. doi:10.1038/nrd.2017.243.
Medical Editorial Team
Medical Content
iMedic Medical Editorial Team – Specialists in Vaccinology, Infectious Disease, and Pulmonology
Medical Review
iMedic Medical Review Board – Independent panel of medical specialists
Evidence Framework
GRADE methodology – Level 1A evidence from systematic reviews and RCTs
Guidelines Followed
WHO, EMA SmPC, FDA Label, CDC ACIP Recommendations
Medical Disclaimer: This information is intended for educational purposes only and does not replace professional medical advice. The content is based on the approved product information (SmPC/prescribing information), peer-reviewed clinical trial data, and international guidelines. Always consult a qualified healthcare provider for personalized medical advice regarding vaccination.
Conflict of Interest: iMedic has no financial relationships with Moderna or any pharmaceutical companies. All content is independently produced without commercial funding or sponsorship.