Managing infection risks in children on biologic therapies

Children receiving biologic and other immunosuppressive therapies require individualized approaches to vaccination, infection prevention, and clinical monitoring, according to Johanna Chang, MD, who emphasized that pediatricians should understand how specific medications affect immune function.

Chang, clinical pediatric rheumatology director at UC San Diego Rady Children's Health, discussed practical considerations for managing children receiving immunomodulatory therapies at the American Academy of Pediatrics (AAP) 2026 National Conference & Exhibition.

She highlighted the importance of distinguishing between live and inactivated vaccines, assessing cumulative immunosuppression when considering infection prophylaxis, and recognizing that certain therapies may mask traditional signs of infection.

Which vaccines are safe for children receiving immunosuppression?

Vaccination is a common concern for families of children receiving immunosuppressive medications, particularly when parents are uncertain whether vaccines remain safe or effective during treatment.

Chang emphasized that the first consideration is whether a vaccine is live or inactivated.

Most routinely administered vaccines are inactivated and can be safely given to children receiving immunosuppressive therapies. Depending on the vaccine and the patient's underlying condition or treatment, additional doses or an expanded vaccination schedule may be recommended to provide adequate protection.

"So when it comes to most vaccines, they are inactivated, and this is absolutely safe to give while a child is on immunosuppression," Chang said.

Live vaccines require more careful consideration because their administration may need to be coordinated with the timing of immunosuppressive treatment.

However, Chang cautioned against assuming that live vaccines are universally contraindicated for every child receiving immunosuppression.

"It doesn't mean that the live vaccine is completely off the table," she said.

Instead, pediatricians should collaborate with the child's treating specialist to determine whether vaccination is appropriate and when it can be administered safely.

Chang also encouraged clinicians to explore the specific concerns families have about vaccination. Parents may worry that a vaccine will cause illness, trigger a flare of the child's underlying condition, or fail to provide protection because of immunosuppression.

Addressing these concerns individually can help pediatricians provide more meaningful counseling and support informed decisions.

When is infection prophylaxis necessary?

Chang explained that receiving a biologic medication does not automatically mean a child requires antimicrobial prophylaxis.

Instead, decisions should reflect the patient's overall immunosuppressive burden, underlying medical condition, and additional infection risk factors.

"So just because a patient is on a biologic doesn't mean that they automatically need prophylaxis," Chang said.

For example, when considering prophylaxis against Pneumocystis jirovecii pneumonia, clinicians should assess whether the patient is receiving high-dose corticosteroids, the duration of steroid exposure, and whether other immunosuppressive medications are being used concurrently.

The cumulative effect of these treatments may be more important than any individual medication.

Chang also identified patients with congenital splenic abnormalities or those who have undergone splenectomy because of an underlying disease as groups that may require specific preventive measures, including penicillin prophylaxis.

These decisions should be individualized rather than based solely on the presence of a biologic prescription.

For pediatricians, maintaining an accurate medication history and understanding the patient's underlying disease can help identify children who may benefit from additional preventive care or specialist consultation.

How do different biologics affect infection risk?

Chang emphasized that infection risks vary depending on the immune pathway targeted by a biologic medication.

For children receiving tumor necrosis factor (TNF)-alpha inhibitors, impaired defense against certain intracellular pathogens is an important concern.

These medications are associated with an increased risk of tuberculosis, making appropriate screening essential.

Patients may also be more susceptible to opportunistic infections.

B-cell–depleting therapies, such as rituximab, present different considerations. Chang explained that these medications can cause prolonged reductions in immunoglobulin G (IgG), potentially increasing susceptibility to sinopulmonary infections.

Interleukin-6 (IL-6) inhibitors, including tocilizumab, can complicate infection recognition by suppressing inflammatory responses.

Children receiving these medications may have a blunted fever response or normal C-reactive protein (CRP) levels despite an active infection.

"So I think all of these things are important to consider when a pediatrician is seeing a patient with a biologic in their office," Chang said.

Understanding the medication's mechanism of action can therefore help clinicians recognize which infections or complications deserve particular attention.

What warning signs should pediatricians monitor?

Beyond infection risk, immunosuppressive medications can cause adverse effects that vary by treatment.

Chang noted that some medications may be associated with elevated liver enzymes or reduced blood cell counts, the latter potentially increasing susceptibility to infection.

Injection-site reactions and infusion reactions are additional considerations for patients receiving certain therapies.

However, Chang emphasized that laboratory findings and conventional signs of infection do not always reflect the severity of illness in immunosuppressed children.

This is particularly relevant for patients receiving medications that interfere with inflammatory signaling.

A child taking an IL-6 inhibitor, for example, may have a clinically significant infection without developing the fever or CRP elevation that would typically prompt concern.

Chang encouraged pediatricians to prioritize the patient's overall clinical appearance and maintain a low threshold for additional evaluation when an immunosuppressed child appears ill.

"I think one thing I would want to point out to pediatricians is that they should really look at the child in front of them," Chang said.

Even when laboratory results appear reassuring or fever is absent, clinicians should consider further evaluation and communication with the prescribing specialist if the child appears unwell.

For pediatricians caring for children receiving biologic therapies, Chang's recommendations underscore the importance of understanding medication-specific risks, coordinating preventive care with subspecialists, and recognizing that serious infections may not always produce typical clinical or laboratory findings.

Reference

Chang J. Biologics and Beyond: Pediatric Care for the Immunosuppressed Child. Presented at: American Academy of Pediatrics 2026 National Conference & Exhibition; October 5, 2026; San Diego, CA.