Oralvac Compact immunotherapy for allergies


You need to read this information with the manufacturer’s leaflet that comes with your medicine. If you have any questions or concerns, please speak to a doctor or nurse caring for you.

Oralvac® Compact is an immunotherapy treatment for allergic reactions. If you have an allergy, your immune system overreacts to a substance that is not harmful. This treatment can weaken your body's response to the substance causing the allergy (the allergen). It helps your immune system get used to the allergen and stop reacting so strongly.

We might recommend Oralvac Compact for you if:

  • you have a severe allergy to house dust mites (tiny bugs that live in house dust), tree pollen or grass pollen
  • your current medicine does not control your symptoms well

This treatment comes as drops that you put under your tongue (sublingual).

This medicine is not officially approved (licensed) for treating your health condition at present. However, your doctor feels that it is safe and effective treatment for you. Read more about unlicensed medicines.

How Oralvac Compact works

We use Oralvac Compact to treat the symptoms of an allergic reaction. The symptoms include:

Substances called allergens cause these symptoms. Almost anything can be an allergen, including pollen, animal fur, food and medicine. 

When you take Oralvac Compact drops, you have a small amount (dose) of the allergen that causes your reaction. By taking lots of small doses, you can build up a tolerance to the allergen that affects you. This reduces the symptoms of your allergic reaction.

How to take Oralvac Compact

Oralvac Compact comes in a small bottle with a pump. You need to take Oralvac Compact 1 time each day, after a meal. 

  1. Pump the drops under your tongue. 
  2. Keep the medicine under your tongue for 1 to 2 minutes.
  3. After this time, swallow the medicine in your mouth. 

Your treatment is in 2 stages:

  1. For the 1st week, you take the maximum number of drops.  
  2. After 1 week, the number of drops that you take each day is reduced. This is called the maintenance phase.

Your doctor explains the full plan and length of treatment to you.

If you forget to take Oralvac Compact

If you forget to take Oralvac Compact for 1 day, take your usual dose as soon as you remember. 

If you have missed more than 1 day of your treatment, contact your medical team as soon as you can. We might need to change the dose of your medicine. This depends on how many treatments you have missed and what stage of treatment you have reached.

Side effects of Oralvac Compact

When you have Oralvac Compact, you take a small amount of a tree pollen, grass pollen or house dust mite allergen. This means that you get some of your usual allergy symptoms. For example, you might have a runny nose or watery eyes. 

You usually get the allergy symptoms straight after you start Oralvac Compact and they gradually fade. 

Please read the manufacturer’s leaflet for more information on side effects. Contact a GP straight away if you have a severe allergic reaction. 

Oralvac and other medicines

You can take most other medicines with Oralvac Compact. This includes your usual treatment for hayfever or asthma. 

Tell your doctor about any medicines that you take. This includes:

  • medicines prescribed for you
  • any medicines that you buy from a pharmacy or shop, such as vitamins, supplements and herbal or alternative medicines

Your doctor checks your medicines and makes sure that you can take them with Oralvac Compact. 

Talk to your doctor about any new medicines before you start them. It is also important to tell any other doctor who treats you that you take Oralvac Compact. They need to know this before you have any medical or dental procedures.

Vaccinations and Oralvac Compact

If you have any vaccines (such as the flu vaccine), do not take Oralvac Compact on the day of your vaccine. 

If you have any reactions to a vaccine, you need to wait until these are completely better before starting Oralvac Compact again. 

Pregnancy and Oralvac Compact

It is not known how Oralvac Compact affects an unborn baby. There is limited evidence available about using Oralvac Compact during pregnancy. For this reason, we do not generally recommend taking Oralvac Compact when you are pregnant.

Please contact your doctor if you become pregnant, or think that you might be pregnant, during treatment. The doctor needs to check your general health and find out if Oralvac Compact has caused you any problems in the past. They can then recommend if you should keep taking Oralvac Compact. 

Breastfeeding and Oralvac Compact

There is no information available about if Oralvac Compact is found in breast milk. For this reason, we recommend that you do not start treatment while you are breastfeeding. Please speak to your doctor for more advice.

Resource number: 4406
Last reviewed: July 2022
Next review: July 2025

Contact us

If you have any questions or concerns, please contact the allergy nurse specialist.

Email: [email protected]

Phone: 020 7188 5830, Monday to Friday, 9am to 5pm

Please call at least 5 working days before your appointment.

We check messages regularly and return your call as soon as possible. Please leave your name and phone number.

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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