Complement Inhibitors and Meningococcal Disease: A Much Higher Risk

People receiving a complement inhibitor are up to 2,000 times more likely to get meningococcal disease than otherwise healthy people. Meningococcal disease is often serious and can be deadly.

Key points

• Complement inhibitors greatly raise the risk of meningococcal disease.
• Vaccination and antibiotics give some protection, but not complete protection.
• Anyone taking a complement inhibitor should seek care quickly for symptoms of meningococcal disease — even if vaccinated or taking antibiotics.

The medicines

Health care providers most often prescribe them for four rare conditions:

• atypical hemolytic uremic syndrome (aHUS), a blood disorder;
• generalized myasthenia gravis (gMG), which causes muscle weakness;
• neuromyelitis optica spectrum disorder (NMOSD), a disorder of the brain and spinal cord;
• paroxysmal nocturnal hemoglobinuria (PNH), a blood disorder.

Protection

• Vaccination. CDC recommends meningococcal vaccination, including regular boosters, for people receiving complement inhibitors. Ask your provider about staying up to date.
• Antibiotics. Some providers prescribe antibiotics to help prevent meningococcal disease in people receiving these medicines.

The risk remains

CDC data suggest that meningococcal vaccines give incomplete protection to people receiving eculizumab, and experts believe the same likely applies to some other complement inhibitors, such as ravulizumab. People on a complement inhibitor can still get meningococcal disease even when vaccinated or taking antibiotics.

If symptoms appear

If you take a complement inhibitor and have symptoms of meningococcal disease, get medical care right away, even if you have been vaccinated or are taking antibiotics — and tell the provider you are taking a complement inhibitor. Each medicine's FDA product label is published on the FDA's Drugs@FDA site.

Sources

• Centers for Disease Control and Prevention, "Meningococcal Disease and People Receiving Complement Inhibitors." https://www.cdc.gov/meningococcal/risk-factors/receiving-complement-inhibitors.html
• Corrected: the source abbreviates generalized myasthenia gravis as "gMC" (gMG). The vaccine-vial illustration is not reproduced.
• Rewritten in hubnx's own words.