Can I receive the Bexsero (meningococcal group B) vaccine during an active infectious mononucleosis infection?

Can You Get Bexero Vaccine with Mono Infection?

Yes, you can receive the Bexsero vaccine during an active infectious mononucleosis infection, as there are no specific contraindications listed in FDA labeling or CDC guidelines that prohibit vaccination during acute viral illnesses like mono.

Understanding the Contraindications

The FDA-approved labeling for Bexsero does not list infectious mononucleosis or other acute viral infections as contraindications to vaccination 1. The ACIP guidelines for meningococcal vaccination similarly do not identify acute infectious mononucleosis as a reason to defer vaccination 2.

General Vaccination Principles During Acute Illness

While the specific evidence documents provided do not explicitly address vaccination during mononucleosis, standard vaccination practice follows these principles:

• Moderate to severe acute illness is typically considered a precaution (not contraindication) for most vaccines, meaning vaccination should be deferred until the person recovers 2
• Mild illness without fever does not preclude vaccination with most vaccines
• The concern with vaccinating during acute illness is primarily about:
  • Difficulty distinguishing vaccine adverse effects from symptoms of the underlying illness
  • Potential (though unproven) reduced immune response to the vaccine during acute infection
  • Incorrectly attributing worsening of the underlying illness to the vaccine

Practical Clinical Approach

For a patient with active infectious mononucleosis:

• If the patient has high fever, severe symptoms, or feels significantly unwell: Defer Bexsero vaccination until clinical recovery 2
• If the patient has mild residual symptoms without fever and is otherwise feeling well: Vaccination can proceed, particularly if there is urgent need (such as during an outbreak or before college enrollment) 2, 3
• Document the clinical decision and inform the patient that distinguishing vaccine side effects from mono symptoms may be challenging

Important Caveats

• Bexsero is only FDA-approved for individuals aged 10-25 years 1
• The most common adverse reactions include injection site pain (≥85%), fatigue (≥40%), headache (≥35%), myalgia (≥30%), and chills (≥15%) 2 - symptoms that overlap significantly with infectious mononucleosis
• Post-vaccination surveillance data from over 5.6 million doses distributed in the United States has not revealed safety concerns related to vaccination during concurrent illnesses 4

Dosing Considerations Once Vaccination Proceeds

• For healthy adolescents aged 16-23 years (Category B recommendation): 2 doses at 0 and 6 months 3
• For persons aged ≥10 years at increased risk: 3 doses at 0,1-2, and 6 months 3
• The minimum interval between any 2 doses is 4 weeks 2, 5