Consumer Medicine Information (CMI) summary
The
full CMI on the next page has more details. If you are worried about using this medicine,
speak to your doctor, nurse or pharmacist.
This medicine is new. Please report side effects that you may experience with this
medicine. See the full CMI for further details.
ENFLONSIA contains the active ingredient clesrovimab. ENFLONSIA is a prescription
medicine to help prevent lung disease caused by Respiratory Syncytial Virus (RSV)
in newborns and babies who are born during or entering their first RSV season.
2. What should I know before my child is given ENFLONSIA?
Your child should not be given ENFLONSIA if they have had a serious allergic reaction
to any of the ingredients in ENFLONSIA.
Talk to your child's doctor if your child has any other medical conditions or any
allergies or takes any other medicines.
3. What if my child is taking other medicines?
Your child can get ENFLONSIA at the same time as routine childhood vaccines.
4. How is ENFLONSIA given?
ENFLONSIA is given as an injection, usually in the thigh muscle, by your child’s healthcare
provider.
5. What should I know after my child is given ENFLONSIA?
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Things you should do
|
Remind any doctor, nurse or pharmacist you visit that your child has been given ENFLONSIA.
Tell your child's doctor and seek medical care right away if your child has any signs
or symptoms of a serious allergic reaction, as these reactions have happened with
other medicines like ENFLONSIA. Signs and symptoms of serious allergic reactions may
include:
Swelling of face, mouth or tongue
Difficulty swallowing or breathing
Unresponsiveness
Bluish color of skin, lips or under fingernails
Muscle weakness
Severe rash, hives or itching
Your child may still get RSV disease after receiving ENFLONSIA. Talk to your child’s
healthcare provider about what symptoms to look for.
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Looking after your medicine
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It is unlikely that you will be asked to store ENFLONSIA. If you are, follow the instructions
in the carton on how to take care of your medicine properly.
Keep it where young children cannot reach it.
|
6. Are there any side effects?
The most common side effects are redness and swelling where your child got the injection,
and rash.
This medicine is subject to additional monitoring. This will allow quick identification
of new safety information. You can help by reporting any side effects you may get.
You can report side effects to your doctor, or directly at www.tga.gov.au/reporting-problems .
Clesrovimab
Full Consumer Medicine Information (CMI)
This leaflet provides important information about getting ENFLONSIA. You should also speak to your child's doctor, nurse or pharmacist if you would like
further information or if you have any concerns or questions about being given ENFLONSIA.
Where to find information in this leaflet:
1. Why is my child being given ENFLONSIA?
ENFLONSIA contains the active ingredient clesrovimab. ENFLONSIA is a prescription
medicine to help prevent lung disease caused by Respiratory Syncytial Virus (RSV)
in newborns and babies who are born during or entering their first RSV season.
RSV season is the time of year when RSV infections are most common, with peak cases
usually occurring between autumn and winter. RSV infection can lead to serious lung
disease.
ENFLONSIA contains antibodies (proteins the body uses to fight harmful germs) to help
prevent RSV disease.
RSV is a common respiratory virus that usually causes symptoms similar to the common
cold but can also affect the lungs. Symptoms of RSV infection may include a runny
nose, trouble feeding, difficulty breathing, coughing, sneezing, wheezing or fever.
Anyone can become infected by RSV and almost all children get an RSV infection by
the time they are 2 years old. While most recover quickly, RSV can cause severe illness
including bronchiolitis (inflammation of the small airways in the lung) and pneumonia
(infection of the lungs) that may lead to hospitalization and even death. Children
at greatest risk include newborns and babies up to 12 months of age, especially those
6 months and younger, or those with heart or lung problems.
2. What should I know before my child is given ENFLONSIA?
Warnings
Your child should not be given ENFLONSIA if they:
Have had a serious allergic reaction to any of the ingredients in ENFLONSIA.
Always check the ingredients listed at the end of this leaflet to make sure your child
can be given this medicine.
Tell your child's healthcare provider:
If your child has a low number of blood platelets (which help blood clotting), a bleeding
problem or bruises easily, or is taking a medicine to prevent blood clots (anticoagulant).
About any medical conditions or allergies your child has or had.
Any medicine your child is given for any other condition.
After being given ENFLONSIA, your child may be at risk of developing certain side
effects. It is important you understand these risks and how to monitor for them. See
additional information under Section
6. Are there any side effects?
Pregnancy and breastfeeding
ENFLONSIA is a medicine for newborns and babies and should not be given to females
who could become pregnant or are breast-feeding.
Children
It has not yet been established if ENFLONSIA can be used in children who are older
than 12 months of age.
3. What if my child is taking other medicines?
Your child can be given ENFLONSIA at the same time as routine childhood vaccines.
Tell your child's doctor, nurse or pharmacist if your child is taking, has recently
taken or might take any other vaccines or medicines, including any medicines, vitamins
or supplements (including herbal supplements) that you buy without a prescription
from your pharmacy, supermarket or health food shop.
Check with your doctor, nurse or pharmacist if you are not sure about what medicines,
vitamins or supplements your child is taking and if these affect ENFLONSIA.
4. How is ENFLONSIA given?
How will my child be given ENFLONSIA?
ENFLONSIA is given as an injection, usually in the thigh muscle, by your child’s healthcare
provider.
When will my child be given ENFLONSIA?
Your child should be given ENFLONSIA before the start of or during the RSV season.
Your child’s healthcare provider can tell you when the RSV season starts in your area.
If your child has surgery for certain types of heart disease, your child’s healthcare
provider may need to give your child an additional ENFLONSIA injection after surgery.
5. What should I know after my child is given ENFLONSIA?
Things you should do
Call your doctor straight away, and seek medical help immediately, if you notice any
signs or symptoms of a serious allergic reaction such as:
swelling of the face, mouth or tongue
difficulty swallowing or breathing
unresponsiveness
bluish color of skin, lips or under fingernails
muscle weakness
severe rash, hives, or itching
Serious allergic reactions have happened with other medicines like ENFLONSIA. Remind
any doctor, nurse or pharmacist you visit that your child has been given ENFLONSIA.
Your child may still get RSV disease after receiving ENFLONSIA. Talk to your child’s
healthcare provider about what symptoms to look for.
Looking after your medicine
It is unlikely that you will be asked to store ENFLONSIA. If you are, follow the instructions
in the carton on how to take care of your medicine properly.
Keep it where young children cannot reach it.
6. Are there any side effects?
All medicines can have side effects. If your child does experience any side effects,
most of them are minor and temporary. However, some side effects may need medical
attention.
See the information below and, if you need to, ask your child's doctor, nurse or pharmacist
if you have any further questions about side effects.
Side effects
Tell your child's doctor, nurse or pharmacist if you notice anything else that may
be making your child feel unwell.
Other side effects not listed here may occur in some children.
Reporting side effects
After you have received medical advice for any side effects you experience, you can
report side effects to the Therapeutic Goods Administration online at
www.tga.gov.au/reporting-problems . By reporting side effects, you can help provide more information on the safety of
this vaccine.
7. Product details
This medicine is only available with a doctor's prescription.
What ENFLONSIA contains
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Active ingredient
(main ingredient)
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clesrovimab 105 mg
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Other ingredients
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arginine hydrochloride
histidine
histidine hydrochloride monohydrate
polysorbate 80
sucrose
water for injections
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ENFLONSIA does not contain any preservatives.
Your child should not be given this medicine if they are allergic to any of these
ingredients.
What ENFLONSIA looks like
ENFLONSIA is a colourless to slightly yellow, clear to slightly opalescent solution
for injection.
ENFLONSIA is available as a prefilled syringe for intramuscular injection.
AUST R 478965
Who distributes ENFLONSIA
Merck Sharp & Dohme (Australia) Pty Limited
Level 1, Building A, 26 Talavera Road
Macquarie Park NSW 2113
CCPPI-MK1654-I-102024
RCN: 000027481-AU
CCPPI-MK1654-122025
RCN: 000028784
This leaflet was prepared in March 2026.
Copyright © 2026 Merck & Co., Inc., Rahway, NJ, USA, and its affiliates. All rights
reserved.