Mvabea (MVA-BN-Filo)

What Is Mvabea and What Is It Used For?

Mvabea is an Ebola vaccine used as the second dose of a 2-dose regimen with Zabdeno to prevent Ebola virus disease in people aged 1 year and older.

Mvabea (also known by its scientific name MVA-BN-Filo) is a multivalent viral vector vaccine developed by Janssen Vaccines & Prevention B.V., part of the Janssen Pharmaceutical Companies of Johnson & Johnson. It was granted marketing authorization by the European Medicines Agency (EMA) in July 2020 as part of a heterologous prime-boost vaccination regimen against Ebola virus disease (EVD). The vaccine is designed to be used exclusively in combination with Zabdeno (Ad26.ZEBOV), which serves as the first dose (prime), while Mvabea serves as the second dose (boost).

Ebola virus disease is a severe, often fatal illness caused by filoviruses of the genus Ebolavirus. The disease was first identified in 1976 near the Ebola River in what is now the Democratic Republic of the Congo. Since then, multiple outbreaks have occurred primarily in sub-Saharan Africa, with the 2013–2016 West Africa epidemic being the largest, causing over 11,000 deaths. EVD has a case fatality rate ranging from 25% to 90%, depending on the viral species and the quality of supportive care available. Given these devastating statistics, the development of effective vaccines has been a global public health priority.

Mvabea is based on a Modified Vaccinia Ankara (MVA) viral vector that has been engineered to express glycoproteins from four different filovirus species: Zaire ebolavirus (the species responsible for the majority of Ebola outbreaks), Sudan ebolavirus, Marburg virus, and Tai Forest virus. This multivalent approach is a key distinguishing feature of the Zabdeno/Mvabea regimen, as it offers the potential for broader protection compared to vaccines targeting a single filovirus species.

The vaccine does not contain live Ebola virus and cannot cause Ebola infection. Instead, the MVA vector acts as a delivery system to introduce filovirus glycoprotein genes into human cells. Once these glycoproteins are expressed on the surface of host cells, the immune system recognizes them as foreign and mounts both antibody (humoral) and T-cell (cellular) immune responses. This dual immune activation is considered important for long-lasting protection against filovirus diseases.

Clinical trials, including the large-scale EBL2002 study conducted in Sierra Leone and other African countries, have demonstrated that the Zabdeno/Mvabea regimen induces robust and durable immune responses. Antibodies against Zaire ebolavirus glycoprotein were detected in the majority of vaccinated individuals, with elevated antibody levels maintained for at least two years following vaccination. The World Health Organization (WHO) Strategic Advisory Group of Experts on Immunization (SAGE) has reviewed the available evidence and supports the use of this regimen in certain epidemiological settings.

What Should You Know Before Receiving Mvabea?

Mvabea should not be given to individuals with a known severe allergic reaction to any component of the vaccine. Special precautions apply for pregnant or breastfeeding women and immunocompromised individuals.

Contraindications

Mvabea must not be administered to individuals who have experienced a severe allergic reaction (anaphylaxis) to any of the vaccine’s components or to a previous dose of Mvabea or a MVA-based vaccine. 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 who had a serious adverse reaction to the first dose of Zabdeno (Ad26.ZEBOV) should not receive the second dose of Mvabea until they have been evaluated by a healthcare professional. The vaccination regimen should be carefully reconsidered in such cases, weighing the risk of Ebola exposure against the risk of another adverse reaction.

Warnings and Precautions

Vaccination with Mvabea should be postponed in individuals suffering from an acute severe illness accompanied by fever. However, the presence of a minor infection, such as a common cold, is not a reason to delay vaccination. Healthcare providers should assess each individual’s clinical status before proceeding.

Individuals with bleeding disorders or those receiving anticoagulant therapy may experience bleeding or bruising at the injection site. In such cases, firm pressure should be applied to the injection site for at least two minutes without rubbing. Subcutaneous injection may be considered as an alternative in patients with severe thrombocytopenia or coagulation disorders, although data on this route of administration are limited.

As with all vaccines, Mvabea may not fully protect all individuals who receive it. The duration of protection conferred by the Zabdeno/Mvabea regimen has not been established definitively, though clinical data suggest immunity persists for at least two years. Booster dose recommendations are being evaluated based on ongoing studies.

The vaccine has not been extensively studied in individuals over 65 years of age. Limited data are available for this population, and the immune response may be reduced in elderly individuals due to age-related immunosenescence. Clinical judgment should be exercised when vaccinating this age group.

Pregnancy and Breastfeeding

There is limited clinical experience with the use of Mvabea during pregnancy. Animal studies with the MVA-BN vector have not shown direct or indirect harmful effects on reproductive toxicity. However, as a precautionary measure, vaccination during pregnancy should be avoided unless the potential benefit outweighs the potential risk to the fetus, such as during an active Ebola outbreak with high exposure risk.

It is not known whether Mvabea components are excreted in human breast milk. A risk to the breastfed infant cannot be excluded. The decision to vaccinate a breastfeeding woman should be made on a case-by-case basis, considering the epidemiological situation and the individual’s risk of Ebola exposure. During active outbreak response, the WHO has indicated that the benefits of vaccination generally outweigh the potential risks for breastfeeding women.

Immunocompromised Individuals

The safety and immunogenicity of Mvabea in immunocompromised individuals, including those living with HIV, have been evaluated in clinical studies. Data from HIV-positive participants suggest that the vaccine is generally well tolerated, though the immune response may be somewhat lower compared to immunocompetent individuals. Vaccination should be considered on a case-by-case basis, particularly in outbreak settings where the risk of Ebola exposure is significant.

How Does Mvabea Interact with Other Drugs?

No clinically significant drug interactions have been identified with Mvabea. However, immunosuppressive medications may reduce the vaccine’s effectiveness.

As a viral vector vaccine, Mvabea is not metabolized by the liver and does not interact with the cytochrome P450 enzyme system. Therefore, pharmacokinetic drug-drug interactions in the traditional sense are not expected. However, certain medications and treatments can influence the immune response to the vaccine, potentially affecting its efficacy.

Immunosuppressive Therapies

Individuals receiving immunosuppressive therapy, including high-dose corticosteroids (equivalent to ≥20 mg prednisolone daily for ≥14 days), chemotherapy, radiation therapy, or biological agents that suppress the immune system (such as TNF inhibitors, rituximab, or other B-cell depleting therapies), may have a diminished immune response to Mvabea. Where possible, vaccination should ideally be completed before initiating immunosuppressive treatment. If this is not feasible, the timing of vaccination relative to immunosuppressive therapy should be discussed with a specialist.

Other Vaccines

Limited data are available on the co-administration of Mvabea with other vaccines. In general, inactivated vaccines can typically be given simultaneously with viral vector vaccines at different injection sites. However, the co-administration of Mvabea with other live viral vector vaccines should be approached with caution, as there may be theoretical concerns about immune interference. If other vaccines are needed, they should preferably be administered at least 14 days before or after Mvabea, unless the clinical situation warrants simultaneous vaccination.

What Is the Correct Dosage of Mvabea?

Mvabea is given as a single intramuscular injection of 0.5 mL approximately 8 weeks after the first dose of Zabdeno, for all age groups from 1 year and older.

The Zabdeno/Mvabea vaccination regimen consists of two doses administered approximately 8 weeks (56 days) apart. Zabdeno (Ad26.ZEBOV) is always given as the first dose (prime), and Mvabea (MVA-BN-Filo) is always given as the second dose (boost). The order of administration is critical and must not be reversed. Both doses are administered as intramuscular injections, preferably into the deltoid muscle of the upper arm in adults and older children, or into the anterolateral thigh in infants and young children.

Adults (18 years and older)

Children and Adolescents (1–17 years)

Elderly (65 years and older)

Missed Dose

If the second dose of Mvabea is not administered at the scheduled time of approximately 8 weeks after Zabdeno, it should be given as soon as possible. Clinical data from the EBL3001 study suggest that acceptable immune responses can still be achieved when the interval between doses is extended beyond 8 weeks, up to approximately 12 months. However, the immune response may not be optimal with extended intervals, and the original 8-week schedule should be followed whenever possible.

There is currently no recommendation to restart the vaccination series if the second dose is significantly delayed. A single dose of Mvabea should be administered regardless of the elapsed time since Zabdeno, though the individual should be counseled that protection may be suboptimal until the vaccination series is completed.

Overdose

Limited data are available on overdose with Mvabea. In clinical trials, the vaccine has been studied at the recommended dose. In the event of an accidental overdose (e.g., administration of more than 0.5 mL), the individual should be monitored for any adverse reactions. There is no specific antidote for vaccine overdose. Treatment should be symptomatic and supportive. Any suspected overdose should be reported to local pharmacovigilance authorities.

What Are the Side Effects of Mvabea?

The most common side effects are injection site pain, fatigue, myalgia, and headache. Most reactions are mild to moderate and resolve within a few days.

Like all vaccines, Mvabea can cause side effects, although not everybody gets them. The safety of the Zabdeno/Mvabea regimen has been evaluated in multiple clinical trials involving thousands of participants across Africa and Europe, including adults, adolescents, and children. The side effects reported below reflect the combined safety data from these trials.

The majority of adverse reactions observed with Mvabea are local reactions at the injection site and systemic symptoms that are typical of vaccination responses. These generally indicate that the immune system is responding to the vaccine and are not a cause for concern. Most reactions are mild to moderate in severity and resolve spontaneously within 1 to 3 days without treatment.

Injection Site Reactions

The most frequently reported side effect is pain at the injection site, occurring in approximately 30–50% of vaccine recipients in clinical trials. Swelling and redness at the injection site are also relatively common. These local reactions typically begin within the first 24 hours after vaccination and resolve within 1 to 3 days. They are generally mild in intensity and do not interfere significantly with daily activities. Applying a cool compress to the injection site may help alleviate discomfort.

Systemic Reactions

Systemic reactions such as fatigue, myalgia, headache, and fever are common after vaccination and reflect the activation of the immune system. Fever is usually low-grade (<39°C / 102.2°F) and resolves within 1 to 2 days. In clinical trials, fever of ≥38°C was reported in approximately 5–15% of adult participants. Antipyretic medications such as paracetamol (acetaminophen) or ibuprofen may be used to manage fever and pain if needed.

Pediatric Population

In clinical trials involving children and adolescents, the side effect profile was generally similar to that observed in adults. Irritability and decreased appetite were additionally reported in younger children (aged 1–3 years). Fever may be more common in young children compared to adults, which is consistent with the general pattern seen with childhood vaccinations.

How Should You Store Mvabea?

Mvabea must be stored frozen at −25°C to −15°C. Once thawed, it can be kept at 2–8°C for up to 30 days.

Proper storage of Mvabea is essential to maintain the vaccine’s potency and efficacy. The vaccine is a biological product containing a live viral vector (Modified Vaccinia Ankara), and improper storage conditions can compromise its effectiveness. Healthcare facilities and vaccination programs must adhere strictly to the recommended cold chain requirements.

Long-Term Storage

Mvabea should be stored in a freezer at −25°C to −15°C (−13°F to 5°F) in the original outer packaging to protect from light. Under these conditions, the vaccine has a shelf life of 36 months from the date of manufacture. The vaccine must be kept in the original carton at all times during storage to ensure protection from light exposure, which can degrade the viral vector.

Thawed Storage

Once thawed, Mvabea can be stored at refrigerator temperature of 2°C to 8°C (36°F to 46°F) for a single period of up to 30 days. The date of removal from the freezer should be clearly written on the outer carton. After the 30-day period, any unused vaccine must be discarded. Do not refreeze Mvabea after it has been thawed — refreezing will compromise the integrity of the viral vector and render the vaccine ineffective.

Pre-Use Handling

Before administration, the thawed vaccine should be allowed to reach room temperature. The suspension should be inspected visually for any particulate matter or discoloration. Mvabea is a colorless to slightly yellowish suspension. If the vaccine appears discolored, contains visible particles, or if the container appears damaged, it should not be used. The vaccine vial should be gently mixed by swirling — do not shake vigorously, as this may damage the viral vector particles.

Keep Mvabea out of the sight and reach of children. Do not use the vaccine after the expiry date stated on the label and carton. The expiry date refers to the last day of the stated month.

What Does Mvabea Contain?

Mvabea contains a Modified Vaccinia Ankara viral vector encoding glycoproteins from four filovirus species, along with standard vaccine excipients.

Active Substance

The active substance in Mvabea is a Modified Vaccinia Ankara Bavarian Nordic (MVA-BN) viral vector that has been genetically modified to express glycoproteins from the following four filovirus species:

• Zaire ebolavirus (Mayinga variant) glycoprotein — responsible for the majority of Ebola outbreaks, including the 2013–2016 West Africa epidemic
• Sudan ebolavirus (Gulu variant) glycoprotein — associated with several outbreaks in East Africa
• Marburg virus (Musoke variant) glycoprotein — causes Marburg virus disease, a related hemorrhagic fever
• Tai Forest virus (formerly Côte d’Ivoire ebolavirus) glycoprotein — a less common filovirus species

Each 0.5 mL dose contains a nominal titer of 0.7 × 10⁸ infectious units (Inf.U) of the MVA-BN-Filo vector. The viral vector is replication-incompetent in human cells, meaning it can enter cells and express the filovirus glycoproteins but cannot multiply to produce new viral particles.

Excipients (Inactive Ingredients)

In addition to the active viral vector, Mvabea contains the following excipients:

• Tris(hydroxymethyl)aminomethane (Tris buffer)
• Sodium chloride
• Water for injections
• Hydrochloric acid (for pH adjustment)

The vaccine does not contain any preservatives, adjuvants, or antibiotics. It is produced in chicken embryo fibroblast (CEF) cells. Individuals with a history of severe allergy to chicken proteins should discuss this with their healthcare provider before vaccination, although the risk of allergic reaction from trace amounts of chicken protein in the final product is considered very low.

Appearance

Mvabea is supplied as a suspension for injection in a single-dose vial containing 0.5 mL. The suspension is colorless to slightly yellowish. Each vial is for single use only and any remaining vaccine should be discarded after the dose has been withdrawn.

How Does the Zabdeno/Mvabea Regimen Work?

The 2-dose regimen uses two different viral vectors (heterologous prime-boost) to generate strong and long-lasting immune protection against Ebola and related filoviruses.

The Zabdeno/Mvabea vaccination regimen employs a heterologous prime-boost strategy, which is considered one of the most effective approaches to generating robust and durable immune responses. This strategy uses two different viral vectors to deliver the same or related antigens in sequential doses, taking advantage of the distinct immunological properties of each vector.

Prime (Zabdeno – Ad26.ZEBOV)

The first dose, Zabdeno, uses a replication-incompetent adenovirus serotype 26 (Ad26) vector encoding the glycoprotein of Zaire ebolavirus. When injected intramuscularly, the adenoviral vector enters host cells and directs the production of the Ebola glycoprotein. This triggers both innate and adaptive immune responses, including the generation of Ebola-specific antibodies and T cells. The Ad26 vector is particularly effective at priming the immune system due to its strong activation of antigen-presenting cells.

Boost (Mvabea – MVA-BN-Filo)

The second dose, Mvabea, uses the MVA vector to deliver glycoproteins from four filovirus species. Because the MVA vector is immunologically distinct from the Ad26 vector used in the first dose, the immune system responds strongly to the boosting dose without being inhibited by pre-existing immunity to the vector itself. This is a key advantage of the heterologous approach over homologous (same-vector) boosting strategies. The MVA boost amplifies and broadens the immune response initiated by Zabdeno, resulting in higher antibody titers and more diverse T-cell responses.

Immunological Outcome

Clinical trial data demonstrate that the heterologous prime-boost regimen generates both humoral immunity (binding and neutralizing antibodies against Ebola glycoprotein) and cellular immunity (CD4+ and CD8+ T-cell responses). Antibody levels peak approximately 21 days after the second dose and remain elevated for at least 2 years based on available follow-up data. The breadth of the immune response, covering multiple filovirus species, represents an important advantage for outbreak preparedness in regions where different filovirus species circulate.