Travelers with Weakened Immune Systems

CDC recommends making sure you are up to date with your COVID-19 vaccines before travel, which includes additional doses for individuals who are immunocompromised or booster doses when eligible. Follow all requirements and recommendations at each location during travel, and take steps to protect yourself and others. If you are traveling internationally, check the COVID-19 Travel Health Notice for your destination and visit the International Travel webpage for requirements and recommendations.

Many illnesses can weaken the immune system, including HIV/AIDS, cancer, liver disease, kidney disease, and multiple sclerosis. In addition, many medicines can weaken the immune system, including steroids, cancer chemotherapy, and drugs used to treat autoimmune diseases like rheumatoid arthritis or psoriasis. Regardless of the cause, if you have a weakened immune system and are planning a trip overseas, make an appointment with your doctor or a travel medicine specialist to talk about what you should do to prepare for safe and healthy travel.

Before You Go

Make an appointment with a doctor at least a month before your trip to discuss vaccines, medications, and travel health advice.

No matter where you go, wash your hands often. Also, try to avoid touching surfaces that other people have touched, such as doorknobs and stair rails, with your bare hands.


woman getting injection

Check CDC’s destination tool to see the vaccines recommended for your destination, and talk to your doctor about which are right for you.

If you have a weakened immune system, you can safely receive most vaccines recommended for travelers. However, the vaccines may be less effective than in people with fully healthy immune systems. Your doctor may recommend blood tests to confirm that a vaccine you received will provide you with adequate protection against disease, or suggest additional precautions to keep you safe.

Vaccines made from live viruses, such as MMR (measles, mumps, and rubella) and varicella, however, are not safe for many people with weakened immune systems. Talk to your doctor what your options are for protecting yourself against these diseases.

Yellow fever vaccine is another example of a vaccine made from a live virus. People whose immune systems are very weak, such as people with low T-cell counts due to HIV infection or people receiving cancer chemotherapy, should not receive yellow fever vaccine. If there is a risk of yellow fever at your destination, CDC recommends delaying your trip until your immune system is healthy enough for you to receive the vaccine. Some countries may require the vaccine, even if there is no risk of yellow fever. If that is the case, ask your doctor about a medical waiver for the vaccine.


taking pills

Make sure your doctor knows about all the medicines you take regularly, including vitamin supplements, so that they can anticipate potential interactions.

You may need to take medicine to prevent malaria, depending on your destination. People with weakened immune systems can get seriously ill from malaria. It is important to follow closely your doctor’s instructions for taking the medicine, which may include taking it for several weeks before and after the trip. You should also take steps to avoid mosquito bites: wear insect repellent, wear long pants and sleeves, and sleep under a bed net if your rooms are open to the outdoors.

Depending on where you are going and what you will be doing, your doctor may also prescribe medicine to prevent altitude illness or to treat travelers’ diarrhea. People with weakened immune systems are especially prone to travelers’ diarrhea. Be sure to follow CDC’s advice for eating and drinking safely.

Overall, if you are feeling sick, do not travel before talking to your doctor.

More Information

Yellow Book: Immunocompromised Travelers