Vaccination for people with bleeding disorders

People who are receiving anticoagulant therapy may develop small haematomas at intramuscular injection sites.

Clarify the duration of anticoagulant therapy and delay immunisation if therapy will be short term.

Unless warfarin or low molecular weight heparin (LMWH) doses are stable, the appropriate levels should be checked in people receiving anticoagulants before they receive a vaccine, if possible. Defer intramuscular injections if the INR is >3.0 (warfarin) or the anti-Xa (LMWH) level 4 hours post-dose is >0.5 units/mL.

The National Hemophilia Foundation's Medical and Scientific Advisory Council (MASAC) recommends the following procedures when administering vaccines in individuals with bleeding disorders:

• Use a fine guage needle (23 gauge or smaller).
• Do not rub the site after the injection, but apply firm pressure for about at least 2 minutes. 
• Let vaccine recipients or their carers know that small haematomas may form. If a haematoma forms, they can apply ice and immobilise the area. 
• Advise patients against using Asprin or NSAIDS for pain relief as these may increase risk of bleeding. Paracetamol may be used instead.
• For patients receiving prophylaxis treatment for hemophilia, vaccination could be given within one day afterwards to decrease the risk of developing a haematoma.

Using a subcutaneous route instead of intramuscular

It is better to use the intramuscular route if that is the recommended route of vaccine administration.

However, when vaccinating someone with haemophilia or on anticoagulant therapy, it may be possible to use the subcutaneous route instead of the intramuscular route. Seek expert advice before using an alternative route.

A person’s immune system may not respond as well if a vaccine usually recommended to be given intramuscularly is given subcutaneously. The person may require, for example, serological tests and extra vaccine doses.^1,2

If a person has haemophilia and is receiving clotting factor replacement or a similar therapy, they should receive intramuscular vaccines as soon as possible after receiving the medicine,³ preferably within one day afterward.⁴

The National Hemophilia Foundation's Medical and Scientific Advisory Council (MASAC) recommends the following procedures when administering vaccines in individuals with bleeding disorders:

• Use a fine guage needle (23 gauge or smaller).
• Do not rub the site after the injection, but apply firm pressure for about at least 2 minutes. 
• Let vaccine recipients or their carers know that small haematomas may form. If a haematoma forms, they can apply ice and immobilise the area. 
• Advise patients against using Asprin or NSAIDS for pain relief as these may increase risk of bleeding. Paracetamol may be used instead.
• For patients receiving prophylaxis treatment for hemophilia, vaccination could be given within one day afterwards to decrease the risk of developing a haematoma.

Using a subcutaneous route instead of intramuscular

It is better to use the intramuscular route if that is the recommended route of vaccine administration.

However, when vaccinating someone with haemophilia or on anticoagulant therapy, it may be possible to use the subcutaneous route instead of the intramuscular route. Seek expert advice before using an alternative route.

A person’s immune system may not respond as well if a vaccine usually recommended to be given intramuscularly is given subcutaneously. The person may require, for example, serological tests and extra vaccine doses.^1,2

1. Wahl M, Hermodsson S. Intradermal, subcutaneous or intramuscular administration of hepatitis B vaccine: side effects and antibody response. Scandinavian Journal of Infectious Diseases 1987;19:617-21.
2. Mannucci PM, Gringeri A, Morfini M, et al. Immunogenicity of a recombinant hepatitis B vaccine in hemophiliacs. American Journal of Hematology 1988;29:211-4.
3. American Academy of Pediatrics. Kimberlin DW, Brady MT, Jackson MA, Long SS, eds. Red Book: 2015 report of the Committee on Infectious Diseases. 30th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2015.
4. National Hemophilia Foundation. MASAC Document 278 - MASAC recommendations on administration of vaccines to individuals with bleeding disorders. New York, United States: 2023. (Accessed 6 July 2023). https://www.hemophilia.org/healthcare-professionals/guidelines-on-care/masac-documents/masac-document-278-masac-recommendations-on-administration-of-vaccines-to-individuals-with-bleeding-disorders