Preventing Infection

You will need to guard against infection for many months after a bone marrow or stem cell transplant.

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After transplant, you will be at risk for infection. Until your immune system recovers, your body will not have all the tools it needs to fight infection on its own.

The first two to four weeks post-transplant are critical, but protecting against infection is an ongoing concern up to a year or two after your transplant, and longer if you develop graft-versus-host disease.

Thorough Hand Washing Is Important

Your medical team will give you guidelines to help prevent infections until your immune system recovers. The most important of these is frequent, thorough hand washing with soap and water before and after:

  • eating or preparing food
  • taking medications
  • touching catheters and wounds

Be sure to also wash your hands after:

  • changing diapers (if you are permitted to do so)
  • touching plants or dirt (if you are permitted to do so)
  • going to the restroom
  • touching animals, especially birds and reptiles
  • touching bodily fluids or items that might have come in contact with bodily fluids such as clothing, bedding or toilets
  • going outdoors or to a public place
  • removing gloves
  • collecting or depositing garbage (if you are permitted to do so)

Avoid Exposure to Infectious Agents 

During the first six months after transplant, and longer for patients on immunosuppressant drugs, you'll want to avoid exposure to sources of infection. Your transplant center may recommend that you avoid:

  • crowds
  • people who have an infection or have been exposed to infection
  • people who were recently vaccinated for chicken pox
  • gardening or digging in dirt
  • walking, wading, swimming or playing in ponds or lakes
  • construction sites and remodeling projects
  • smoking and being around people who smoke cigarettes, cigars, e-cigarettes, a piper or marijuana
  • well water that has not been treated

Cleaning kitchen counters and bathrooms daily with a solution of one part bleach to 10 parts water can help eliminate infectious agents. 

 Pets after Transplant?

Rules vary among transplant centers as to whether or not you can have pets in the home while you are recovering.

Your transplant center may ask you to avoid:

  • contact with an animal that is sick
  • reptiles such as lizards, snakes, turtles and iguanas and items they touch
  • juvenile pets (juvenile pets are more likely to scratch than mature pets)
  • chicks and ducklings
  • exotic pets such as monkeys or chinchillas
  • cleaning litter boxes or cages, disposing of animal waste or other activities that put you in touch with animal feces
  • touching bird droppings
  • cleaning fish tanks

Your transplant center may also advise you to:

  • feed pets only high-quality commercial food or thoroughly human food
  • keep cat litter boxes away from areas where food is prepared or eaten
  • keep cats indoors
  • not adopt stray cats
  • cover backyard sandboxes to prevent cats from using it as a litter box.


After a stem cell transplant, it is likely that antibodies provided by previous vaccines are lost or depleted. International concensus guidelines on vacciation after transplant suggest that patients be re-vaccinated 6-18 months after transplant  for:

  • diphtheria
  • tetanus
  •  pneumococcus
  • Hemophilus, influenza type B
  • polio

The guidelines recommend waiting at least two years after transplant to receive the MMR live virus vaccine for measles, mumps, and rubella.

Your transplant team may recommend that you get the flu vaccine starting at six months after transplant. Discuss this issue with your transplant doctor to determine the appropriate timing of re-vaccinations for you.

COVID-19 (SARS-CoV-2 virus)

The COVID-19 virus is a concern for patients with a weak immune system. Transplant recipients, as well as those with whom the patient is often in contact, should receive annual vaccines to minimize the risk of developing a severe COVID infection.

If you develop COVID-19 infection, it may persist and can cause pneumonia. There are treatments for COVID-19, such as Paxlovid™, which can help resolve the infection more quickly.

Better Safe Than Sorry

At the first sign of any fever or infection, immediately call your doctor.

Infections that you would normally ignore can pose a serious threat to your if your immune system is weak. Infections are often easier to treat if detected early.

Watch a video about infections after transplant.

(To view this page in Spanish click here)

Next Page: Nutrition after Transplant

Updated June 2024