Sublivac Birch

What Is Sublivac Birch and What Is It Used For?

Quick Answer: Sublivac Birch is a sublingual allergen immunotherapy containing a standardized extract of birch pollen (Betula verrucosa). It is prescribed for adults and children from 5 years of age with moderate to severe allergic rhinitis or rhinoconjunctivitis caused by birch pollen. Daily drops placed under the tongue gradually reprogramme the immune system to tolerate birch pollen, reducing symptoms during the pollen season and beyond.

Sublivac Birch belongs to a class of treatments known as sublingual allergen immunotherapy (SLIT). Unlike antihistamines, intranasal corticosteroids, or decongestants – which only suppress symptoms once the allergic reaction has begun – Sublivac Birch modifies the underlying immune response that causes birch pollen allergy. The active ingredient is a purified, standardized allergen extract derived from the pollen of the silver birch (Betula verrucosa, also known as Betula pendula), one of the most clinically important tree pollen allergens in Northern and Central Europe.

The product is indicated for patients with clinically confirmed birch pollen allergy who experience moderate to severe symptoms of allergic rhinitis (sneezing, nasal congestion, runny nose, nasal itching) and/or allergic conjunctivitis (itchy, watery, red eyes), with or without mild-to-moderate controlled allergic asthma. Treatment is typically considered when symptoms remain troublesome despite appropriate use of symptomatic medication, when side effects of symptomatic therapy limit its use, or when patients wish to modify the long-term course of their allergic disease rather than treat symptoms each year.

The mechanism of action of sublingual immunotherapy involves repeated exposure of the oral mucosa to gradually controlled doses of the birch pollen allergen. Specialized dendritic cells in the sublingual mucosa – particularly oral Langerhans cells – capture the allergen and present it to the immune system in a tolerogenic context. Over weeks to months this drives a shift in the immune response from the Th2-dominant, IgE-mediated allergic pathway towards a more regulatory profile, characterized by induction of allergen-specific regulatory T cells and production of protective IgG4 blocking antibodies. These "blocking" antibodies bind the allergen before it can cross-link IgE on mast cells and basophils, reducing histamine release and, consequently, allergic symptoms.

Sublivac Birch is manufactured by HAL Allergy BV, a Dutch specialist allergy pharmaceutical company with decades of experience in producing standardized allergen extracts. The product forms part of the wider Sublivac portfolio, which includes single-allergen and tailored multi-allergen preparations for various pollen, mite, and animal dander allergies. The potency is standardized in Allergy Units Nordic (AUN) per millilitre, a bioassay-based unit that accounts for both the allergen content and its biological activity.

What Should You Know Before Taking Sublivac Birch?

Quick Answer: Sublivac Birch should not be used in patients with severe uncontrolled asthma, active malignancy, severe immunodeficiency, or certain autoimmune conditions. The first dose must be administered under medical supervision. Recent mouth wounds, oral infections, or dental procedures require treatment pauses. Always disclose all medications, pregnancy status, and underlying health conditions to your allergist before starting therapy.

Contraindications

Sublivac Birch should not be used if any of the following apply to you:

• Hypersensitivity to excipients: Known allergy to any of the inactive ingredients in the formulation, including phenol (preservative), glycerol, sodium chloride, sodium hydroxide, or hydrochloric acid.
• Severe or uncontrolled asthma: Severe asthma (e.g. FEV1 below 70% of predicted despite treatment), or an asthma exacerbation within the preceding three months, represents an absolute contraindication because the risk of treatment-induced bronchospasm is unacceptably high.
• Active malignancy: Ongoing cancer therapy or active malignant disease, because immune modulation during treatment could have unpredictable effects on tumour biology and complicate oncological management.
• Severe immunodeficiency or immune system disorders: Primary immunodeficiencies, AIDS, severe secondary immunodeficiency, or ongoing use of high-dose immunosuppressive therapy, since a functioning immune system is required for the treatment to work.
• Active autoimmune disease: Systemic autoimmune disorders that are active or poorly controlled (e.g. active systemic lupus erythematosus, vasculitis, multiple sclerosis) may be exacerbated by immune stimulation.
• Chronic inflammatory oral disease: Severe oral inflammation (e.g. oral lichen planus, erosive oral mucositis) or an open wound in the mouth may dramatically increase systemic absorption of the allergen and raise the risk of severe reactions.

Warnings and Precautions

Inform your allergist before starting Sublivac Birch if any of the following apply:

• Mild to moderate asthma: Even well-controlled asthma increases the baseline risk of respiratory reactions and requires pre-treatment spirometry and clear asthma control criteria before each dose escalation step.
• Previous reactions to immunotherapy: A history of systemic reactions to any prior allergen immunotherapy (injection or sublingual) warrants a cautious individualized approach, often including supervised updosing and premedication with antihistamines.
• Elevated baseline serum tryptase or mastocytosis: Patients with mast cell disorders have a significantly higher risk of severe anaphylactic reactions and require specialist evaluation before treatment initiation.
• Cardiovascular disease: Severe coronary artery disease, recent myocardial infarction, or uncontrolled arrhythmias may complicate treatment of a rare systemic reaction; a cardiology review before starting therapy is prudent.
• Chronic use of beta-blockers or ACE inhibitors: These medications can interfere with the emergency treatment of anaphylaxis and may increase the severity of allergic reactions. Where clinically possible, alternatives may be considered before starting immunotherapy.
• Recent dental procedures or mouth wounds: Oral surgery, tooth extraction, or significant mouth ulcers require a treatment pause of at least 7 days to allow mucosal healing before resuming sublingual dosing.
• Active viral or fungal oral infection: Herpes labialis, oral candidiasis, or pharyngitis may locally amplify allergic reactions and warrant a short pause in treatment until the infection resolves.
• Eosinophilic oesophagitis: Case reports have linked sublingual immunotherapy to the development or worsening of eosinophilic oesophagitis. Any new swallowing difficulty, chest pain on swallowing, or food impaction should prompt immediate consultation.
• Vaccinations: Routine vaccinations are generally compatible with ongoing treatment, although a 7-day interval between the immunotherapy dose and vaccine administration is often recommended to minimize confounding reactions.

Children and Adolescents

Sublivac Birch is generally approved from 5 years of age and is widely used in paediatric allergology. Children often respond very well to sublingual immunotherapy, and a growing body of evidence indicates that treating allergic rhinitis during childhood may reduce the subsequent risk of developing asthma and new allergic sensitizations – the so-called "preventive" effect of allergen immunotherapy. Treatment decisions in children should always be individualized by a paediatric allergist, weighing symptom severity, impact on quality of life, school performance, and the family's ability to support daily adherence.

In children under 5 years, the safety and efficacy of Sublivac Birch have not been systematically established, and routine use is not recommended. In older children, the dosing schedule follows the same principles as in adults, although updosing may be performed more gradually to minimize the risk of local reactions that young children may find uncomfortable.

Pregnancy and Breastfeeding

Sublingual immunotherapy should generally not be initiated during pregnancy, since dose escalation introduces a small but real risk of systemic allergic reactions that could potentially compromise the pregnancy. If pregnancy occurs during an established maintenance phase, most specialists recommend continuing treatment after an individual risk-benefit discussion, since interruption and later restart would require a repeat updosing and a fresh exposure risk.

The allergen extract itself is not expected to reach clinically significant levels in systemic circulation, and there is no evidence of direct harm to the foetus from ongoing sublingual immunotherapy. Breastfeeding is generally considered compatible with ongoing treatment. As always, discuss any change in your medical status with your allergist so that the dosing regimen can be individualized.

Driving and Operating Machinery

Sublivac Birch is not known to impair the ability to drive or operate machinery in the vast majority of users. However, some people experience transient dizziness, fatigue, or drowsiness, particularly during the first few days of treatment. If you notice any of these symptoms, avoid driving and other safety-critical activities until you are confident about how the medicine affects you.

How Does Sublivac Birch Interact with Other Drugs?

Quick Answer: Several medications can interact with Sublivac Birch by either increasing the risk of severe allergic reactions or reducing the effectiveness of emergency treatment. The most clinically important interactions involve beta-blockers, ACE inhibitors, tricyclic antidepressants, MAO inhibitors, and systemic immunosuppressants. Always provide your allergist with a complete list of prescription, over-the-counter, and herbal medicines before starting treatment.

Drug interactions with allergen immunotherapy matter for two reasons: some drugs increase the likelihood of systemic allergic reactions, while others can impair the cardiovascular response to adrenaline (epinephrine), the first-line treatment for anaphylaxis. For these reasons, full medication reconciliation with your prescribing physician and allergist is essential before starting therapy, and any new medication added during the 3-year course should be reviewed for potential interactions.

Major Interactions

Minor Interactions and Considerations

What Is the Correct Dosage of Sublivac Birch?

Quick Answer: Sublivac Birch is taken as daily drops held under the tongue for 1–2 minutes before being swallowed. Treatment begins with a short dose build-up phase of several days using increasing numbers of drops, followed by a maintenance dose typically of a few drops once daily. The full course is approximately 3 years of continuous, year-round dosing. All dose adjustments must be made by the prescribing allergist.

Sublivac Birch is administered entirely at home after the first supervised dose, making it one of the most patient-friendly forms of allergen immunotherapy. The drops are placed directly under the tongue using the integrated pipette, held in the mouth for 1 to 2 minutes to allow oral mucosal absorption, and then swallowed. The medicine should be taken on an empty stomach, ideally 20 to 30 minutes before a meal and before brushing teeth, and the same time each day should be chosen to support adherence.

Dosing Schedule

The treatment is divided into two clinical phases: a short build-up phase during which the dose is gradually increased under medical guidance, and a longer maintenance phase during which a constant daily dose is taken for the remainder of the 3-year course. Exact dose numbers must always be taken from the current product summary and the physician's prescription, but the principles of dosing are as follows.

The build-up schedule can vary between clinics and should be tailored to tolerability. Patients who experience significant local oral reactions during updosing may have the schedule extended, or an antihistamine may be added as premedication. The goal is to reach the target maintenance dose within 1 to 2 weeks, at which point the patient continues the same daily dose for the remainder of treatment. Unlike some other pollen immunotherapies that are taken only before and during the pollen season, Sublivac Birch is designed for continuous year-round administration, because stopping and restarting treatment each year would require repeated updosing and could compromise the long-term disease-modifying effect.

Children

The standard paediatric schedule mirrors the adult protocol from 5 years of age, although updosing may be performed more slowly if a child is anxious about the tingling sensation that can accompany initial doses. Parents or carers are trained in dose administration at the first clinic visit and should supervise dosing until the child is old enough to self-administer reliably. A treatment diary is particularly valuable in paediatric practice to record any local or systemic reactions, missed doses, and concurrent infections that may temporarily pause therapy.

Elderly Patients

No dose adjustment is recommended solely on the basis of age. However, elderly patients are more likely to have cardiovascular comorbidities, polypharmacy, and subtle swallowing difficulties that warrant individualized assessment. A careful medication review before starting treatment, with particular attention to beta-blockers, ACE inhibitors, and tricyclic antidepressants, is essential. In practice, allergen immunotherapy is less commonly initiated after the age of 65, although selected patients can benefit when symptoms are severe and alternatives are limited.

Missed Dose

If you forget to take a single dose, take it as soon as you remember on the same day if possible. Do not take a double dose to compensate for a missed one. If several days of treatment are missed, follow these general rules, always in consultation with your allergist:

• 1–7 days missed: Resume treatment at the normal maintenance dose.
• 8–14 days missed: Restart at a reduced dose, then build back up to maintenance over a few days.
• More than 14 days missed: A full repeat of the supervised build-up schedule is usually necessary before resuming maintenance.

The longer the gap, the higher the risk of an allergic reaction when restarting at the previous dose. Always contact the clinic if you have been unable to take the medicine for more than a week, particularly if this coincides with an illness, recent dental work, or new medication.

Overdose

Accidental intake of several times the prescribed dose is unlikely to cause serious harm in most patients, but it may increase the likelihood and severity of local and systemic allergic reactions. Symptoms can include pronounced oral itching, swelling of the lips or tongue, generalized itching, hives, abdominal cramps, nausea, or – rarely – wheezing, throat tightness, or anaphylaxis. If an overdose occurs, do not take further doses, contact your allergist or local emergency service immediately, and seek medical evaluation. If signs of anaphylaxis develop, use an adrenaline (epinephrine) auto-injector if one has been prescribed and call emergency services.

What Are the Side Effects of Sublivac Birch?

Quick Answer: Most side effects of Sublivac Birch are mild local reactions inside the mouth: itching, tingling, or swelling of the tongue, lips, or palate, and irritation of the throat or ears. These typically appear within the first 1–2 weeks of treatment and resolve spontaneously. Systemic reactions are uncommon and severe anaphylaxis is rare, but any widespread hives, breathing difficulty, or cardiovascular symptoms require immediate medical attention.

Like all medicines, Sublivac Birch can cause side effects, although not everyone experiences them. The majority of reactions reflect direct contact of the allergen with mucosal mast cells in the mouth, pharynx, and upper gastrointestinal tract – the expected biological consequence of administering an allergen to a sensitized patient. Local reactions usually appear within minutes of administration and diminish over 1 to 2 weeks as mucosal tolerance develops. Below is a breakdown of reported side effects by frequency category according to the standard Council for International Organizations of Medical Sciences (CIOMS) classification.

The overall safety profile of sublingual immunotherapy is favourable compared with subcutaneous injection therapy. A systematic review in the Cochrane Database of Systematic Reviews estimated that serious adverse events are very rare, and that local oral reactions are the most common cause of treatment discontinuation. In clinical experience, most patients who persist through the first 2 weeks of treatment find that the mouth itching and tingling resolve on their own and are well tolerated thereafter.

If local reactions become distressing, an antihistamine can be taken as premedication. Dose reduction or a slower build-up schedule may also be appropriate. Persistent or escalating reactions, and any systemic symptoms, should prompt a specialist review rather than ongoing self-treatment. Your allergist will balance symptom tolerability against the long-term benefit of continuing therapy.

How Should You Store Sublivac Birch?

Quick Answer: Sublivac Birch should be stored in a refrigerator at 2°C to 8°C (36°F to 46°F). It must not be frozen. Keep the bottle upright in its original carton to protect it from light, and keep out of the sight and reach of children. Once opened, the bottle is typically usable for several months when stored correctly – follow the specific expiry instructions on the label.

Correct storage is essential to maintain the potency and safety of Sublivac Birch. The standardized allergen extract is a biological product that can degrade if exposed to heat, freezing, or prolonged light, which may reduce its clinical effect and alter its immunogenic properties in unpredictable ways.

• Temperature: Store in a refrigerator at 2°C to 8°C (36°F to 46°F). Do not freeze. If the product is accidentally frozen, discard it and contact your pharmacist for a replacement.
• Light protection: Keep the bottle in the original carton to protect from light exposure. Avoid storing near windows or on open refrigerator shelves exposed to internal light.
• Short excursions: Brief exposure to room temperature (e.g. during transport from pharmacy to home, or for the duration of dosing) is acceptable. Consult the patient information leaflet for specific manufacturer guidance on maximum time out of refrigeration.
• After opening: Once a bottle is first opened, it remains usable for a defined period indicated on the label – typically several months. Record the date of first opening on the bottle or packaging.
• Expiry date: Do not use after the expiry date (EXP) printed on the label. The expiry date refers to the last day of the stated month.
• Appearance check: The solution should be clear and colourless. Do not use if the liquid is cloudy, discoloured, or contains visible particles.
• Keep out of reach of children: Although designed for paediatric use under supervision, accidental ingestion of the entire bottle by a young child could cause significant local and systemic reactions.
• Travel: For short trips, transport the bottle in a cool bag or insulated container. For longer journeys, discuss with your pharmacist whether temporary out-of-fridge storage remains safe.

Dispose of any unused medicine in accordance with local regulations for biological pharmaceutical waste – typically by returning the bottle to a pharmacy. Do not pour the liquid down the drain or place the bottle in household waste, both for environmental reasons and to avoid unintended exposure.

What Does Sublivac Birch Contain?

Quick Answer: The active ingredient is a standardized allergen extract of birch pollen (Betula verrucosa) at a potency of 40,000 AUN/ml. Inactive ingredients typically include glycerol (as solvent and stabilizer), phenol (preservative), sodium chloride, and water for injections, with pH adjusted using sodium hydroxide or hydrochloric acid.

Active Ingredient

The active substance is a purified, standardized allergen extract prepared from birch pollen of the species Betula verrucosa (silver birch, synonym Betula pendula). The extract contains the full spectrum of clinically relevant birch pollen allergens, of which the major allergen Bet v 1 is responsible for sensitization in more than 95% of birch-allergic patients. Minor allergens such as Bet v 2 (profilin) and Bet v 4 (polcalcin) are also present and contribute to the full immunological profile of the extract.

The potency is expressed in Allergy Units Nordic (AUN) per millilitre, a bioassay-based standardization unit. One bottle is supplied at a single strength of 40,000 AUN/ml, which is used for both the build-up and maintenance phases through varying numbers of drops.

Inactive Ingredients (Excipients)

• Glycerol: Serves as both a solvent and a stabilizer, preventing aggregation of allergen proteins and supporting long-term potency.
• Phenol: Preservative that prevents microbial contamination in a product intended for repeated multidose use.
• Sodium chloride: Maintains isotonicity of the solution.
• Sodium hydroxide and/or hydrochloric acid: Used in small quantities to adjust the pH of the solution to physiological values.
• Water for injections: The solvent base of the solution.

Appearance and Packaging

Sublivac Birch is a clear, colourless solution supplied in a multidose bottle fitted with a metered pipette for sublingual administration. Each bottle is labelled with batch number, expiry date, and storage instructions. The pack includes a patient information leaflet with detailed dosing instructions, a treatment diary, and contact information for the manufacturer and prescribing clinic.