Certain Medical Conditions as a Risk Factor

Certain medical conditions and medications may weaken the immune system and increase someone’s risk for meningococcal disease. CDC recommends meningococcal vaccination for people with these conditions. Vaccine recommendations vary by age, vaccine type, and condition.

Persistent complement component deficiencies

CDC recommends people with a persistent complement component deficiency receive two meningococcal vaccines, including booster shots throughout life:

  • Meningococcal conjugate (MenACWY) vaccine
  • Serogroup B meningococcal (MenB) vaccine

Complement component deficiencies refer to disorders of the ‘complement system,’ which helps the body fight off infections. Examples of complement component deficiencies include C3, C5-9, properdin, factor H, and factor D. These disorders are very rare and usually genetic.

Complement inhibitor medications

People who receive complement inhibitors such as eculizumab (Soliris®) and ravulizumab (Ultomiris™) are also at increased risk for meningococcal disease.  Doctors most commonly prescribe complement inhibitors for four rare medical conditions:

  • Atypical hemolytic uremic syndrome (aHUS), a blood disorder
  • Paroxysmal nocturnal hemoglobinuria (PNH), a blood disorder
  • Generalized myasthenia gravis (MG), a disorder that leads to muscle weakness
  • Neuromyelitis optica spectrum disorder (NMOSD), a disorder of the brain and spinal cord

Learn more about the risk for meningococcal disease among patients who receive complement inhibitors.

Functional or anatomic asplenia

CDC recommends people with functional or anatomic asplenia receive two meningococcal vaccines, including booster shots throughout life:

  • MenACWY
  • MenB

Someone with anatomic asplenia does not have a spleen (for instance, if it was surgically removed). Someone with functional asplenia has a spleen but it doesn’t work the way that it should. People with sickle cell anemia have functional asplenia. The spleen is an important organ for fighting meningococcal infections because it helps produce antibodies and filter bacteria.

HIV infection

CDC recommends people living with HIV receive a MenACWY vaccine, including booster shots throughout life. This vaccine provides protection against meningococcal disease caused by serogroups A, C, W, and Y. For people living with HIV who get meningococcal disease, 4 in 5 cases (80%) are due to serogroups C, W, and Y. A low CD4 countexternal icon or high viral load increases risk for meningococcal disease for people living with HIV.

Learn more about meningococcal vaccine recommendations.

Meningococcal Disease: What People Living with HIV Need to Know

Meningococcal Disease Fact Sheet: What People Living with HIV Need to Know pdf icon[2 pages]

This fact sheet describes common outcomes of meningococcal disease, a rare but very serious illness. People living with HIV are at increased risk for meningococcal disease and should get a meningococcal conjugate vaccine.

Page last reviewed: February 7, 2022