What is meningococcal disease?

Short Answer

Meningococcal disease can refer to any illness that is caused by the type of bacteria called Neisseria meningitidis, also known as meningococcus. The illness most people are familiar with is meningococcal meningitis, which people sometimes just call meningitis. This usually means the linings (meninges) of the brain and spinal cord have become infected with these bacteria. But these bacteria can also cause other severe illnesses, like bloodstream infections (bacteremia or septicemia). The meningococcal vaccine is 85-100% effective in preventing infection from most strains of the bacteria; there are other strains that aren’t covered by the vaccine.







Symptoms, Incubation, & Complications

When someone has meningococcal meningitis, the protective membranes (meninges) covering their brain and spinal cord become infected and swell. The symptoms include sudden onset of fever, headache, and stiff neck. It is often accompanied by other symptoms, such as:

  • Nausea
  • Vomiting
  • Photophobia (increased sensitivity to light)
  • Altered mental status (confusion)

The symptoms of meningococcal meningitis can appear quickly or over several days. Typically they develop within three to seven days after exposure.

In newborns and infants, the classic symptoms of fever, headache, and neck stiffness may be absent or difficult to notice. The infant may appear to be slow or inactive, irritable, vomiting, or feeding poorly. In young children, doctors may also look at the child’s reflexes, which can also be a sign of meningitis. Meningococcal meningitis is very serious and can be fatal. In fatal cases, deaths can occur in as little as a few hours. In nonfatal cases, permanent disabilities can include hearing loss and brain damage.

Another potential outcome of meningococcal infection is bloodstream infection, either septicemia or bacteremia. The more serious of the two is septicemia. When caused by Neisseria meningitidis bacteria, it is known as meningococcal septicemia or meningococcemia. When someone has meningococcal septicemia, the bacteria enter the bloodstream and multiply, damaging the walls of the blood vessels and causing bleeding into the skin and organs.

Symptoms may include:

  • Fatigue
  • Vomiting
  • Cold hands and feet
  • Cold chills
  • Severe aches or pain in the muscles, joints, chest, or abdomen
  • Rapid breathing
  • Diarrhea
  • In the later stages, a dark purple rash


Meningococcal septicemia is very serious and can be fatal. In fatal cases, deaths can occur in as little as a few hours. In nonfatal cases, permanent disabilities can include amputation of toes, fingers, or limbs, or severe scarring as a result of skin grafts.


Neisseria meningitidis bacteria are spread through the exchange of respiratory and throat secretions like spit (e.g., living in close quarters, kissing). While the bacteria are not spread by casual contact or by simply breathing the air where a person with meningococcal disease has been, bacteria sometimes spread to people who have had close or lengthy contact with someone who has meningococcal disease.

High-risk Populations

  • College freshmen [R1] living in dormitories.
  • Laboratory personnel who are routinely exposed to meningococcal bacteria.
  • U.S. military recruits.
  • Anyone traveling to, or living in, a part of the world where meningococcal disease is common, such as parts of Africa.
  • Anyone who has a damaged spleen, or whose spleen has been removed.
  • Anyone who has persistent complement component deficiency (an immune-system disorder).
  • People who might have been exposed to meningitis during an outbreak.


There are two meningococcal vaccines available in the United States:

  • Meningococcal polysaccharide vaccine (MPSV4)
  • Meningococcal conjugate vaccine (MCV4)

MCV4 is the preferred vaccine for people in these groups who are 9 months through 55 years of age. MPSV4 can be used for adults older than 55. Both vaccines can prevent four types of meningococcal disease, including two of the three types most common in the United States and a type that causes epidemics in Africa. There are other types of meningococcal disease; the vaccines do not protect against these.


Safety & Side Effects
As many as half the people who get meningococcal vaccines have mild side effects, such as redness or pain where the shot was given. If these problems occur, they usually last for one or two days. They are more common after MCV4 than after MPSV4. A small percentage of people who receive the vaccine develop a mild fever. Moderate and severe side effects are extremely rare.



All 11- and 12-year-olds should be vaccinated with meningococcal conjugate vaccine (MCV4). A booster dose should be given at age 16 years. For adolescents who receive the first dose at age 13 through 15 years, a one-time booster dose should be administered, preferably at age 16 through 18 years, before the peak in increased risk. Adolescents who receive their first dose of MCV4 at or after age 16 years do not need a booster dose.


Since the Vaccine Was Introduced…

In 1978, the first meningococcal vaccines were licensed in the United States and were effective against two of the major groups of meningococcus. Currently, licensed vaccines provide some protection against all groups except B; there is no licensed vaccine for group B in the U.S.

Originally, the vaccines were developed to control meningococcal disease in the armed forces. All U.S. military recruits are given meningococcal polysaccharide vaccine prior to induction.