AFLUNOV: Uses, Dosage & Side Effects
A pre-pandemic influenza vaccine containing H5N1 surface antigens with MF59 adjuvant, used for active immunization against avian influenza in pandemic preparedness programs
AFLUNOV is a pre-pandemic influenza vaccine authorized by the European Medicines Agency (EMA) for active immunization against the H5N1 subtype of influenza A virus. It contains inactivated surface antigens (haemagglutinin and neuraminidase) from an H5N1 influenza virus strain, combined with the MF59C.1 oil-in-water adjuvant to enhance immune response. AFLUNOV is designed for use in pandemic preparedness programs and is intended to prime the immune system so that individuals can mount a faster, stronger protective response if exposed to H5N1 influenza. The vaccine is administered as two intramuscular injections given at least three weeks apart and requires a prescription. AFLUNOV plays a critical role in national and international pandemic influenza preparedness strategies.
Quick Facts: AFLUNOV
Key Takeaways
- AFLUNOV is a pre-pandemic influenza vaccine containing inactivated H5N1 surface antigens with the MF59C.1 adjuvant, authorized by the EMA for use in pandemic preparedness programs to protect against avian influenza A (H5N1).
- The primary vaccination course consists of two intramuscular injections of 0.5 mL each, administered at least 3 weeks apart into the deltoid muscle, with a booster dose possible 12 months after the initial series.
- The MF59 adjuvant allows a lower antigen dose (7.5 micrograms haemagglutinin) while generating robust immune responses, and has a well-established safety profile from decades of use in seasonal influenza vaccines.
- Most side effects are mild and transient, including injection site pain, headache, fatigue, and muscle aches, typically resolving within 1 to 3 days without treatment.
- AFLUNOV should not be given to individuals with a history of anaphylaxis to any vaccine component, including egg proteins, kanamycin, neomycin, formaldehyde, or polysorbate 80.
What Is AFLUNOV and What Is It Used For?
AFLUNOV is an adjuvanted, inactivated influenza vaccine specifically developed to address the threat of an H5N1 avian influenza pandemic. The H5N1 subtype of influenza A virus, commonly referred to as avian influenza or bird flu, is a highly pathogenic strain that primarily circulates among wild birds and domestic poultry. While human infections with H5N1 are relatively uncommon, the virus has caused outbreaks in multiple countries and has been associated with a high case fatality rate in humans. The World Health Organization (WHO) and other international public health bodies have identified H5N1 as a virus with significant pandemic potential, meaning it could mutate to allow efficient human-to-human transmission and cause a global pandemic.
AFLUNOV contains purified surface antigens (haemagglutinin and neuraminidase) derived from the influenza virus strain A/turkey/Turkey/1/2005 (H5N1)-like strain, specifically the reassortant NIBRG-23 developed at the National Institute for Biological Standards and Control (NIBSC). The virus used in production is grown in embryonated chicken eggs using standard influenza vaccine manufacturing processes, then inactivated and purified to isolate the surface antigens. Each 0.5 mL dose contains 7.5 micrograms of haemagglutinin (HA), which is considerably lower than the 15 micrograms typically used in seasonal influenza vaccines. This reduced antigen dose is made possible by the inclusion of the MF59C.1 adjuvant.
The MF59C.1 adjuvant is an oil-in-water emulsion based on squalene, a naturally occurring substance found in plant oils, shark liver oil, and human sebum. The adjuvant works by creating a depot effect at the injection site, recruiting immune cells, enhancing antigen uptake and presentation, and stimulating both innate and adaptive immune responses. MF59 has been used in commercially available seasonal influenza vaccines (such as Fluad/FLUAD Tetra) since 1997 and has been administered to hundreds of millions of individuals worldwide, establishing a robust safety record. In the context of pandemic vaccines, the adjuvant serves a particularly important function: because the general population has little or no pre-existing immunity to novel influenza strains like H5N1, an adjuvanted vaccine can generate stronger, broader, and more durable immune responses than a non-adjuvanted formulation with the same antigen dose.
AFLUNOV was authorized by the European Medicines Agency (EMA) through the centralized authorization procedure for use across the European Union. The vaccine is intended for use as part of national pandemic influenza preparedness plans and is primarily stockpiled by governments and international organizations for deployment in the event of an emerging H5N1 pandemic or in situations of heightened risk. The decision to deploy AFLUNOV would be made by national public health authorities in coordination with the WHO and regional bodies such as the European Centre for Disease Prevention and Control (ECDC).
The concept of pre-pandemic vaccination is a key component of the WHO Global Influenza Preparedness Plan. By vaccinating healthcare workers, essential service personnel, and potentially broader populations before or during the early stages of a pandemic, countries can reduce the initial impact of the virus, slow transmission, and buy time for the development and distribution of a strain-matched pandemic vaccine. Clinical trials have demonstrated that AFLUNOV generates seroprotective antibody responses in the majority of vaccinated individuals, meeting the criteria established by the Committee for Medicinal Products for Human Use (CHMP) for pandemic influenza vaccines.
AFLUNOV is part of a broader pandemic preparedness strategy. It is designed to prime the immune system against H5N1 so that if a pandemic occurs, vaccinated individuals may develop faster and more robust protection. In a pandemic scenario, a single booster dose of a strain-matched vaccine may be sufficient for primed individuals, rather than the full two-dose primary series required for unvaccinated people. This antigen-sparing strategy is critical when vaccine supply is limited.
What Should You Know Before Receiving AFLUNOV?
Contraindications
There are specific situations in which AFLUNOV must not be used. Understanding these contraindications is essential for safe vaccination and should be assessed by a healthcare professional before administration.
- Anaphylaxis to vaccine components: AFLUNOV must not be given to anyone who has experienced a severe allergic reaction (anaphylaxis) to any of the active substances, any of the excipients, or to residues from the manufacturing process including egg proteins (ovalbumin, chicken proteins), kanamycin, neomycin, formaldehyde, cetylpyridinium chloride (CPC), and polysorbate 80.
- Previous anaphylaxis to influenza vaccine: Individuals who have had an anaphylactic reaction to a previous influenza vaccination should not receive AFLUNOV unless vaccination is considered essential by a physician and appropriate resuscitation equipment is immediately available.
Warnings and Precautions
As with all injectable vaccines, appropriate medical treatment and supervision should always be available in case of a rare anaphylactic reaction following administration. Vaccination should be postponed in individuals suffering from acute severe febrile illness. A minor infection such as a cold should not delay vaccination.
Several precautions should be taken into account before administering AFLUNOV. Healthcare providers should carefully evaluate the benefit-risk balance for each individual, particularly in the following circumstances:
- Febrile illness: Vaccination should be postponed in individuals who are acutely unwell with a moderate to severe febrile illness. A mild illness or low-grade fever is not generally a reason to defer vaccination, but clinical judgment should be applied on a case-by-case basis.
- Immunodeficiency: Individuals with immunodeficiency, whether due to disease (such as HIV infection or primary immunodeficiency) or immunosuppressive treatment (such as corticosteroids, chemotherapy, or organ transplant medications), may have a diminished immune response to AFLUNOV. Vaccination may still be recommended in these individuals, but the level of protection achieved may be reduced.
- Thrombocytopenia and bleeding disorders: AFLUNOV should be given with caution to individuals with thrombocytopenia (low platelet count) or any bleeding disorder, as intramuscular injection may cause bleeding at the injection site. Firm pressure should be applied to the site without rubbing for at least two minutes after injection.
- Egg allergy: AFLUNOV is produced in embryonated chicken eggs and may contain trace amounts of egg proteins (ovalbumin). Individuals with a known egg allergy that has not resulted in anaphylaxis may still be vaccinated under medical supervision with appropriate observation. Those with a history of anaphylaxis to egg should not receive the vaccine.
- Latex sensitivity: The pre-filled syringe tip cap may contain natural rubber latex. Individuals with known latex sensitivity should inform their healthcare provider before vaccination.
- Fainting (syncope): Fainting can occur following or even before any injection. Measures should be in place to prevent injury from falls, particularly in adolescents and young adults.
AFLUNOV should not be administered intravenously or subcutaneously under any circumstances. The vaccine must be given by intramuscular injection only, preferably into the deltoid muscle of the upper arm. Inadvertent intravascular administration could lead to severe adverse reactions.
It is important to note that vaccination with AFLUNOV may not protect all vaccinated individuals. The level of protection can vary depending on the individual's age, immune status, and the degree of match between the vaccine strain and the circulating pandemic strain. Cross-protective immunity against drifted H5N1 variants has been demonstrated in clinical studies, but the extent of cross-protection against a novel pandemic strain cannot be predicted with certainty.
Pregnancy and Breastfeeding
Limited clinical data are available on the use of AFLUNOV during pregnancy. Animal reproductive studies with MF59-adjuvanted influenza vaccines have not shown any harmful effects on embryo-foetal development. However, as a precaution, AFLUNOV should only be used during pregnancy when the expected benefit to the mother outweighs the potential risk to the foetus. In a pandemic situation, the benefit-risk assessment may favor vaccination of pregnant women, as influenza infection during pregnancy is associated with increased morbidity and mortality for both the mother and foetus.
AFLUNOV may be used during breastfeeding. Inactivated influenza vaccines are generally considered compatible with breastfeeding, and vaccination of breastfeeding women may provide passive protection to the nursing infant through transfer of antibodies in breast milk. Healthcare providers should discuss the benefits and potential risks of vaccination with breastfeeding women on an individual basis.
Women of childbearing potential should be informed that there is no evidence that influenza vaccination causes fertility problems. Seasonal influenza vaccines containing MF59 have been administered to millions of women of reproductive age without evidence of adverse reproductive outcomes.
How Does AFLUNOV Interact with Other Drugs?
AFLUNOV, as an inactivated vaccine, has a relatively low potential for interactions with other medications compared to live vaccines. However, certain drug categories can influence the immune response generated by the vaccine. Healthcare providers should review the patient's current medication list before administration to identify any potential interactions.
The following considerations apply to the concurrent use of AFLUNOV with other medications and vaccines:
Concomitant Vaccines
AFLUNOV may be co-administered with other inactivated vaccines, including seasonal influenza vaccines, provided that different injection sites are used for each vaccine. When multiple vaccines are given simultaneously, they should be injected into different limbs (e.g., one in each deltoid muscle) to allow proper monitoring of any local reactions. Co-administration with live vaccines has not been specifically studied, but the general principles of vaccine administration suggest that inactivated vaccines like AFLUNOV do not interfere with the immune response to live vaccines.
Immunosuppressive Medications
Immunosuppressive therapy, including high-dose systemic corticosteroids, chemotherapeutic agents, calcineurin inhibitors (such as ciclosporin or tacrolimus), and biological immunomodulators (such as anti-TNF agents or anti-CD20 antibodies like rituximab), may significantly reduce the immune response to AFLUNOV. In patients receiving these medications, vaccination should ideally be timed to coincide with periods of lowest immunosuppression, if clinically feasible. Despite potentially reduced efficacy, vaccination is still recommended for immunosuppressed individuals, as some protection may be better than none in a pandemic scenario.
| Interacting Drug/Class | Effect | Clinical Significance | Recommendation |
|---|---|---|---|
| Systemic corticosteroids (high-dose) | May reduce antibody response | Moderate | Vaccinate; monitor immune response if possible |
| Chemotherapy agents | May significantly reduce immune response | Major | Time vaccination between chemotherapy cycles if possible |
| Anti-CD20 antibodies (e.g., rituximab) | May severely impair B-cell response | Major | Vaccinate at least 6 months after last rituximab dose |
| Calcineurin inhibitors | May reduce antibody response | Moderate | Vaccinate; may need booster to achieve protection |
| Other inactivated vaccines | No known interference | Low | May co-administer at different injection sites |
| Anticoagulants (e.g., warfarin) | Increased bleeding risk at injection site | Low to moderate | Use a fine needle; apply firm pressure for 2+ minutes |
Patients should inform their healthcare provider about all medications they are currently taking, including prescription drugs, over-the-counter medicines, herbal supplements, and any recent vaccinations. This information helps the healthcare provider assess the optimal timing and potential risks of AFLUNOV administration.
What Is the Correct Dosage of AFLUNOV?
Adults (18 years and older)
Primary Vaccination Course
Two doses of 0.5 mL each, administered by intramuscular injection into the deltoid muscle of the upper arm. The second dose should be given at least 3 weeks after the first dose. Clinical trials have evaluated intervals of 3 weeks between doses, and this schedule has been shown to induce seroprotective antibody levels in the majority of vaccinated individuals within 21 days after the second dose.
Booster Dose
A single booster dose of 0.5 mL may be administered 12 months after the first dose of the primary vaccination series. The booster dose is intended to maintain and strengthen immunity in previously primed individuals. Clinical data have shown that a booster dose elicits a rapid and strong anamnestic (memory) immune response, with antibody levels rising significantly within 7 days of the booster and peaking at approximately 21 days.
| Patient Group | Dose | Schedule | Route |
|---|---|---|---|
| Adults (18–64 years) | 0.5 mL (7.5 µg HA) | 2 doses, ≥3 weeks apart | Intramuscular (deltoid) |
| Elderly (≥65 years) | 0.5 mL (7.5 µg HA) | 2 doses, ≥3 weeks apart | Intramuscular (deltoid) |
| Booster (all adults) | 0.5 mL (7.5 µg HA) | 12 months after first primary dose | Intramuscular (deltoid) |
Children and Adolescents
AFLUNOV is currently authorized for use in adults aged 18 years and older. Clinical experience in children and adolescents under 18 years of age is limited. No dosing recommendations can be made for this population outside of a pandemic scenario. During a pandemic, national health authorities may extend recommendations to younger age groups based on emerging clinical data and benefit-risk assessments. In such circumstances, adjusted doses or schedules may be recommended by public health authorities.
Elderly (65 years and older)
The dosage for elderly individuals is the same as for younger adults: two doses of 0.5 mL administered at least 3 weeks apart, with a booster at 12 months. Clinical studies have included subjects aged 65 years and older and have demonstrated that AFLUNOV elicits immunogenicity in this age group, although antibody responses may be somewhat lower compared to younger adults, consistent with age-related immunosenescence. The MF59 adjuvant plays a particularly important role in boosting immune responses in the elderly population, as this age group typically shows reduced responses to non-adjuvanted influenza vaccines.
Missed Dose
If the second dose of the primary vaccination series is delayed beyond the recommended 3-week interval, it should be administered as soon as possible. There is no need to restart the vaccination course. Clinical data suggest that extending the interval between the first and second dose does not significantly diminish the final antibody response, and in some cases a longer interval may actually enhance the immune response. However, the individual remains inadequately protected until they receive the full two-dose series.
Overdose
No cases of overdose with AFLUNOV have been reported. In the event that a dose larger than recommended is inadvertently administered, the individual should be closely monitored for any adverse reactions. Based on experience with other influenza vaccines, overdose is unlikely to cause serious adverse effects beyond an increased frequency or intensity of the expected local and systemic reactions. There is no specific antidote for vaccine overdose; management would be symptomatic and supportive.
What Are the Side Effects of AFLUNOV?
Like all vaccines, AFLUNOV can cause side effects, although not everybody gets them. The safety profile of AFLUNOV is based on clinical trial data involving thousands of subjects who received MF59-adjuvanted H5N1 influenza vaccines. The safety profile is consistent with that of other MF59-adjuvanted influenza vaccines that have been used extensively worldwide. Most adverse reactions are mild to moderate in severity and resolve spontaneously within a few days without treatment.
Side effects have been categorized according to their frequency of occurrence in clinical studies. The frequency categories used are defined as follows: very common (affects more than 1 in 10 people), common (affects 1 in 10 to 1 in 100 people), uncommon (affects 1 in 100 to 1 in 1,000 people), and rare (affects fewer than 1 in 1,000 people).
Very Common
Affects more than 1 in 10 people
- Injection site pain
- Injection site redness (erythema)
- Injection site hardening (induration)
- Injection site swelling
- Headache
- Fatigue
- Muscle pain (myalgia)
- General malaise
Common
Affects 1 in 10 to 1 in 100 people
- Joint pain (arthralgia)
- Nausea
- Fever (pyrexia, ≥38°C)
- Chills
- Injection site bruising (ecchymosis)
- Sweating
Uncommon
Affects 1 in 100 to 1 in 1,000 people
- Dizziness
- Diarrhea
- Vomiting
- Abdominal pain
- Skin rash
- Injection site warmth
- Influenza-like illness
Rare
Affects fewer than 1 in 1,000 people
- Lymphadenopathy (swollen lymph nodes)
- Paraesthesia (tingling or numbness)
- Drowsiness
- Urticaria (hives)
- Pruritus (itching)
Not Known
Frequency cannot be estimated from available data
- Anaphylaxis (severe allergic reaction)
- Angioedema (swelling of face, lips, or throat)
- Guillain-Barré syndrome (extremely rare)
- Convulsions (seizures)
- Vasculitis (inflammation of blood vessels)
The injection site reactions observed with AFLUNOV may be slightly more pronounced than those seen with non-adjuvanted influenza vaccines. This is a known characteristic of MF59-adjuvanted vaccines and is related to the local inflammatory response induced by the adjuvant, which is integral to its mechanism of enhancing immunity. These local reactions are generally self-limiting and do not require medical treatment.
Elderly individuals (65 years and older) may experience a lower frequency of local and systemic reactions compared to younger adults. This observation is consistent with the general pattern of reduced immune reactogenicity associated with immunosenescence in older populations.
Seek immediate medical attention if you experience signs of a severe allergic reaction (anaphylaxis) after vaccination: difficulty breathing, swelling of the face, lips, tongue, or throat, rapid heartbeat, dizziness, or collapse. These reactions are extremely rare but require emergency treatment. Contact your healthcare provider if any side effect persists for more than 3 days or becomes severe.
Post-marketing surveillance data from MF59-adjuvanted influenza vaccines (including seasonal vaccines) have confirmed the favorable safety profile observed in clinical trials. Regulatory authorities including the EMA continue to monitor the safety of AFLUNOV and related vaccines through established pharmacovigilance systems. Healthcare professionals are encouraged to report any suspected adverse reactions through their national reporting systems.
How Should You Store AFLUNOV?
Proper storage of AFLUNOV is essential to maintain the vaccine's potency and safety. Vaccines are biological products that are sensitive to temperature extremes, and deviations from recommended storage conditions can reduce or eliminate their effectiveness. The following storage guidelines apply to AFLUNOV pre-filled syringes:
- Temperature: Store in a refrigerator at 2°C to 8°C (36°F to 46°F). Do not freeze. If the vaccine has been frozen, it must be discarded as freezing can damage the adjuvant emulsion and alter the vaccine's physical properties, potentially reducing its efficacy and safety.
- Light protection: Keep the pre-filled syringe in the outer carton in order to protect from light. Exposure to direct sunlight or strong artificial light can degrade the vaccine components.
- Before use: Allow the vaccine to reach room temperature (approximately 15 to 25°C) before administration. This typically takes 15 to 30 minutes. Gently shake the syringe before use to resuspend the contents and produce a uniform, milky-white suspension. Do not use the vaccine if it appears to contain particles or has changed color after shaking.
- After opening: AFLUNOV is supplied as a single-dose pre-filled syringe and should be used immediately once prepared for injection. Any unused vaccine or waste material should be disposed of in accordance with local requirements for medical waste.
- Expiry date: Do not use AFLUNOV after the expiry date stated on the carton and label. The expiry date refers to the last day of that month. Under pandemic stockpile conditions, shelf-life extension may be evaluated and authorized by regulatory authorities based on ongoing stability data.
- Cold chain management: In institutional settings, AFLUNOV should be stored in a pharmaceutical-grade refrigerator with temperature monitoring. Any temperature excursion outside the recommended range should be documented and the affected vaccine should not be used until suitability has been confirmed by the manufacturer or a qualified pharmacist.
Keep this vaccine out of the sight and reach of children. Do not dispose of AFLUNOV via household waste. Ask your pharmacist how to dispose of unused vaccines responsibly.
What Does AFLUNOV Contain?
Active Substance
The active substance in AFLUNOV is influenza virus surface antigens (haemagglutinin and neuraminidase) derived from the strain A/turkey/Turkey/1/2005 (H5N1)-like strain, using the reassortant NIBRG-23. Each 0.5 mL dose contains 7.5 micrograms of haemagglutinin (HA). The virus is propagated in embryonated chicken eggs, inactivated with formaldehyde, and purified to isolate the surface antigens. The final vaccine product contains only the purified surface proteins, not intact virus particles, meaning it cannot cause influenza infection.
Adjuvant: MF59C.1
The MF59C.1 adjuvant is an integral part of the AFLUNOV formulation and is essential for achieving adequate immune responses with the low antigen dose. Each 0.5 mL dose contains the following adjuvant components:
- Squalene: 9.75 mg – a naturally occurring organic compound found in shark liver oil and olive oil, also produced endogenously in the human body as a precursor in cholesterol synthesis
- Polysorbate 80: 1.175 mg – an emulsifying agent widely used in food and pharmaceutical products
- Sorbitan trioleate: 1.175 mg – a surfactant that helps stabilize the oil-in-water emulsion
Other Ingredients (Excipients)
In addition to the active substance and adjuvant, AFLUNOV contains the following excipients that serve as buffers and stabilizers:
- Sodium chloride
- Potassium chloride
- Potassium dihydrogen phosphate
- Disodium phosphate dihydrate
- Magnesium chloride hexahydrate
- Calcium chloride dihydrate
- Sodium citrate
- Citric acid
- Water for injections
Manufacturing Residues
The vaccine may contain trace residues from the manufacturing process, including:
- Egg proteins: Ovalbumin and other chicken proteins (from egg-based production)
- Kanamycin and neomycin: Antibiotics used during production to prevent bacterial contamination
- Formaldehyde: Used for virus inactivation
- Cetylpyridinium chloride (CPC): Used in the purification process
These residues are present in very small amounts, typically well below the levels that would cause allergic reactions in most individuals. However, individuals with known anaphylactic sensitivity to any of these substances should not receive AFLUNOV.
AFLUNOV is a milky-white suspension supplied in a 0.5 mL pre-filled syringe with or without a needle. Before use, the syringe should be gently shaken to ensure a uniform suspension. The vaccine should be visually inspected before administration; do not use if the suspension contains visible particles or appears discolored after shaking.
Frequently Asked Questions About AFLUNOV
AFLUNOV is specifically designed as a pre-pandemic vaccine targeting the H5N1 avian influenza virus, which is fundamentally different from the strains covered by seasonal influenza vaccines. Seasonal flu vaccines are reformulated each year to match the circulating seasonal influenza strains (typically H1N1, H3N2, and influenza B lineages) and are recommended for annual vaccination. AFLUNOV, in contrast, targets a potentially pandemic strain that does not currently circulate efficiently among humans but poses a significant pandemic threat. The vaccine contains the MF59 adjuvant because the general population has little to no pre-existing immunity against H5N1, necessitating an enhanced immune response. Receiving AFLUNOV does not replace the need for annual seasonal influenza vaccination.
Yes, the MF59 adjuvant has an extensive safety record spanning over 25 years of use. It was first licensed in 1997 in the seasonal influenza vaccine Fluad and has since been administered to hundreds of millions of individuals worldwide, including elderly populations, young children, and pregnant women. Extensive post-marketing surveillance, clinical trials, and independent safety reviews have consistently confirmed its favorable safety profile. The adjuvant may cause slightly more local reactions (such as injection site pain and swelling) compared to non-adjuvanted vaccines, but these are generally mild, self-limiting, and are a sign of the immune system being activated. MF59 contains squalene, a substance naturally produced by the human body and found in many foods.
Two doses are required because the H5N1 influenza virus is a novel strain to which most people have no pre-existing immunity. Unlike seasonal influenza where people typically have some baseline immunity from previous infections or vaccinations, H5N1 is largely unfamiliar to the human immune system. The first dose primes the immune system by introducing the viral antigens and initiating the development of antibody-producing B cells and memory T cells. The second dose, given at least 3 weeks later, boosts this initial response to generate higher and more durable levels of protective antibodies. Clinical trials have shown that a single dose alone is insufficient to achieve seroprotective antibody levels in the majority of individuals.
AFLUNOV is designed primarily for pandemic preparedness rather than routine occupational protection. However, in situations where poultry workers or veterinary staff are at increased risk of exposure to H5N1, national health authorities may recommend pre-pandemic vaccination as part of a comprehensive occupational health strategy. AFLUNOV can provide some level of cross-protective immunity against H5N1 strains, though the degree of protection depends on how closely the circulating strain matches the vaccine strain. Occupational protection against avian influenza should also include proper use of personal protective equipment (PPE), biosecurity measures, and surveillance protocols, regardless of vaccination status.
Clinical studies have shown that antibody levels following the primary two-dose series of AFLUNOV persist for at least 6 to 12 months, after which they begin to decline. However, immunological memory (in the form of memory B cells and T cells) is maintained for considerably longer. This means that even when circulating antibody levels have waned, a booster dose or exposure to the virus can trigger a rapid and strong anamnestic (recall) response. The booster dose given at 12 months has been shown to restore and exceed the antibody levels achieved after the primary series. Long-term follow-up studies suggest that immune memory persists for several years, supporting the concept that primed individuals would respond rapidly to a pandemic-matched vaccine or natural exposure.
AFLUNOV is produced in embryonated chicken eggs and may contain trace amounts of egg protein (ovalbumin). If you have a mild egg allergy (e.g., mild hives after eating eggs), you may still be able to receive AFLUNOV under medical supervision with appropriate monitoring. However, if you have a history of anaphylaxis (severe, life-threatening allergic reaction) to eggs or egg-containing products, AFLUNOV should not be administered. In a pandemic scenario, the benefit-risk balance may be reassessed, and vaccination under closely supervised medical conditions with immediate access to emergency treatment may be considered for individuals with severe egg allergy. Always inform your healthcare provider about any allergies before receiving any vaccine.
References
- European Medicines Agency (EMA). AFLUNOV Summary of Product Characteristics. Last updated 2024. Available at: www.ema.europa.eu
- World Health Organization (WHO). Pandemic Influenza Preparedness and Response: A WHO Guidance Document. Geneva: WHO; 2023.
- European Centre for Disease Prevention and Control (ECDC). Guide to Public Health Measures to Reduce the Impact of Influenza Pandemics in Europe. Stockholm: ECDC; 2024.
- WHO Strategic Advisory Group of Experts (SAGE) on Immunization. Recommendations on the use of pre-pandemic influenza vaccines. Weekly Epidemiological Record. 2024.
- Banzhoff A, et al. MF59-adjuvanted H5N1 vaccine induces immunologic memory and heterotypic antibody responses in non-elderly and elderly adults. PLoS One. 2009;4(2):e4384.
- Vesikari T, et al. Oil-in-water emulsion adjuvant with influenza vaccine in young children. N Engl J Med. 2011;365(15):1406-1416.
- Nicholson KG, et al. Safety and antigenicity of non-adjuvanted and MF59-adjuvanted influenza A/Duck/Singapore/97 (H5N3) vaccine: a randomised trial of two potential vaccines against H5N1 influenza. Lancet. 2001;357(9272):1937-1943.
- O'Hagan DT, et al. The history of MF59 adjuvant: a phoenix that arose from the ashes. Expert Rev Vaccines. 2013;12(1):13-30.
- World Health Organization. Influenza (Avian and other zoonotic). Fact Sheet. Updated 2024. Available at: www.who.int
- Committee for Medicinal Products for Human Use (CHMP). Guideline on Influenza Vaccines: Non-clinical and Clinical Module. EMA/CHMP/VWP/457259/2014. European Medicines Agency; 2024.
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This article was last reviewed on and reflects the most current evidence available at that time. Medical information is updated regularly as new research becomes available. For the latest prescribing information, consult the official Summary of Product Characteristics (SmPC) from the EMA or consult your healthcare professional.