What to Avoid While on Biologics?

October 14, 2025 •

4 min read

Because biologics work by suppressing or modulating parts of the immune system, individuals taking these medications face an increased risk of infection. This makes it crucial to understand what to avoid while on biologics to minimize health risks.

Quick Summary

Taking biologics requires awareness of certain risks. Key precautions involve avoiding live vaccines, minimizing exposure to infections, observing food safety, considering drug interactions, and taking special measures when traveling.

Key Points

Avoid Live Vaccines: Steer clear of live-attenuated vaccines like MMR, Zostavax, and Yellow Fever, as they can cause serious infections in immunocompromised individuals.
Practice Strict Hygiene: Wash hands frequently and avoid close contact with sick people to prevent infections, for which you are at higher risk.
Watch Your Diet: Avoid raw or undercooked foods such as meat, seafood, and eggs, along with unpasteurized dairy, to prevent foodborne illness.
Communicate with Your Doctor: Always inform your healthcare provider of any other medications or supplements, as interactions are possible and require careful assessment.
Screen for Latent Infections: Ensure you are screened for dormant infections like tuberculosis and hepatitis B before starting biologic treatment.
Travel Smart: When flying, carry refrigerated biologics in your carry-on luggage to prevent them from freezing in the cargo hold.
Monitor for Side Effects: Be aware of potential signs of infection or other side effects and contact your doctor if they occur.

Biologic medications are an effective treatment for many autoimmune conditions and chronic inflammatory diseases, but they also require patients to take specific precautions to stay healthy. By intentionally altering the immune system's response, biologics make the body more vulnerable to infections. This guide outlines the essential things to avoid while on this class of medication, from dietary considerations to vaccinations and travel.

Live Vaccines

One of the most critical things to avoid while on biologics is live-attenuated vaccines. These vaccines contain a weakened but still live version of a virus or bacteria to provoke an immune response. For individuals with a suppressed immune system, this could potentially cause a severe or life-threatening infection, or a complication from the vaccine itself.

Examples of live vaccines to avoid include:

Measles, Mumps, Rubella (MMR)
Zostavax (live shingles vaccine)
Yellow Fever
Varicella (chickenpox)
Some forms of the oral typhoid vaccine

In contrast, inactivated vaccines, which contain killed viruses or bacteria, are generally considered safe and highly recommended for people on biologics. This includes the annual influenza shot and the pneumococcal vaccine. Before starting any biologic therapy, a thorough assessment of your vaccination status by your doctor is essential. If you need a live vaccine, it should ideally be administered before starting treatment or a specified period after stopping.

Infections

Since biologics weaken the immune system, patients are at a higher risk of contracting new infections and reactivating latent ones.

Preventing new infections

Avoid sick people: Stay away from anyone with an active infection, such as a cold, flu, or respiratory illness.
Practice excellent hygiene: Frequent and thorough hand washing with soap and water is one of the most effective ways to prevent illness. Use hand sanitizer when soap and water are not available.
Wear a mask: Consider wearing a mask in crowded public spaces, especially during cold and flu season, to minimize exposure to respiratory illnesses.
Address illness promptly: If you develop symptoms of an infection, even a mild one, contact your doctor. While some mild infections like a cold can be managed, more serious ones may require temporarily stopping your medication.

Screening for latent infections

Before beginning biologic therapy, your doctor will screen you for dormant infections that could become active once your immune system is suppressed. This most commonly includes:

Tuberculosis (TB)
Hepatitis B

Food and Diet

Patients on biologics need to be more vigilant about food safety to prevent foodborne illness, which can pose a greater threat to an immunocompromised individual.

Foods to avoid or limit:

Raw or undercooked meats, poultry, and seafood: This includes rare steaks, sushi, and oysters, which can harbor harmful bacteria.
Raw or undercooked eggs: Avoid foods containing raw eggs, such as some homemade salad dressings or cookie dough.
Unpasteurized dairy products: This includes unpasteurized milk and soft cheeses like feta, brie, and camembert.
Fresh sprouts: Raw sprouts can carry bacteria and should be avoided.
Alcohol: Excessive alcohol consumption can increase the risk of side effects like liver damage and infection with some biologics. Always discuss alcohol use with your healthcare provider.
Processed foods: Some processed foods are high in unhealthy fats and sugar, which can contribute to inflammation and interfere with overall health.

Medication Interactions

While biologics are not metabolized in the same way as many small-molecule drugs, interactions are still possible, particularly with other immune-modulating drugs.

Immunomodulators: Combining biologics with other immunosuppressants like methotrexate or azathioprine can increase the risk of serious infections. This combination is sometimes used to increase efficacy, but requires careful risk assessment by a doctor.
Other drug classes: Biologics can also affect the clearance and metabolism of other drugs by influencing immune responses and cytokine levels. Always inform your doctor and pharmacist about all medications, supplements, and herbal remedies you are taking.

Travel Precautions

Traveling, especially internationally, requires additional planning for patients on biologics.

Essential travel tips:

Carry-on medication: Always pack biologics that require refrigeration in your carry-on luggage with a cooler bag and ice packs. The cargo hold of an airplane can get cold enough to freeze and ruin your medication.
Medical documentation: Bring a letter from your doctor and your prescription to explain your medication and needs to airport security and customs officials.
Sufficient supplies: Ensure you have enough medication for the entire duration of your trip, plus a little extra, in case of delays.
Travel insurance: Get health insurance that covers your medical condition while abroad.
Destination-specific risks: Be aware of potential infection risks and necessary vaccinations for your destination. If a live vaccine is required, discuss timing with your doctor.

Comparison Table: Live vs. Inactivated Vaccines


Feature	Live-Attenuated Vaccines	Inactivated (Killed) Vaccines
Suitability for Biologics Patients	Generally contraindicated	Recommended and safe
Composition	Weakened but live virus/bacteria	Killed virus/bacteria
Risk for Immunocompromised	Risk of developing the illness	No risk of developing the illness from the vaccine
Immune Response	Strong, long-lasting	May require boosters for ongoing protection
Examples	MMR, Zostavax (live shingles), Yellow Fever	Annual flu shot, Shingrix (non-live shingles), Pneumococcal

Conclusion

Staying informed about what to avoid while on biologics is a vital part of managing your health. From steering clear of certain vaccines and high-risk foods to taking precautions against infection and planning carefully for travel, each step contributes to your safety and well-being. The most important action you can take is to maintain open and consistent communication with your healthcare provider about all aspects of your treatment and lifestyle. This partnership ensures you receive the maximum therapeutic benefit from your medication while minimizing potential risks.

Authoritative Resource

For further information on navigating life with autoimmune diseases and potential treatments, a resource such as the Arthritis Foundation provides comprehensive guidance.

Frequently Asked Questions

It is best to discuss alcohol consumption with your doctor. Excessive alcohol can increase the risk of certain side effects, like liver damage, with some biologics, and it may interfere with the medication's effectiveness.

Contact your doctor if you develop an infection. For mild infections like a cold, you may continue your medication. However, for more serious infections, your doctor might advise temporarily stopping the biologic until you recover.

Pack your refrigerated biologics in your carry-on luggage in a cooler bag with ice packs. The baggage compartment on planes can freeze medication. It is also wise to have a doctor's letter and enough supplies for your trip.

Yes. Avoid raw or undercooked foods, such as meat, seafood, and eggs. You should also steer clear of unpasteurized dairy products and raw sprouts.

Live vaccines contain a weakened, live version of a virus or bacteria. Since biologics suppress your immune system, there is a risk that you could contract the disease from the vaccine itself. Inactivated vaccines are a safe alternative.

While less frequent than with small-molecule drugs, interactions can occur, especially with other immunosuppressants. Biologics can also influence the metabolism of other drugs. Always tell your doctor about all medications you are taking.

Before starting treatment, your doctor will test you for latent infections like tuberculosis or hepatitis B. If a latent infection is discovered and reactivated, your doctor will manage it, which may include temporarily stopping the biologic and starting specific treatment.