Meningococcal disease is an infection caused by a strain of bacteria called Neisseria meningitidis. This invastive bacteria is one of the leading causes of bacterial meningitis in children aged 2 to 18 in the U.S.
Meningococcal disease can include meningitis -- a serious, potentially life-threatening inflammation of the membranes covering the brain and spinal cord -- and/or a life-threatening blood infection. Meningococcal disease can cause limb loss through amputation, hearing loss, problems with the nervous system, mental retardation, seizures, and strokes.
Fortunately, meningococcal disease is preventable, and the key to prevention is the meningococcal vaccine. Here is information about the vaccine that you can use to help protect yourself and your family from meningococcal disease.
How Is Meningococcal Disease Spread and Who Is Most at Risk?
Meningococcal disease is not as contagious as other illnesses, such as a cold or the flu. But it is spread by contact with infected respiratory and throat secretions. That can happen with coughing, kissing, or sneezing.
Because the risk increases with close or prolonged contact with an infected person, family members in the same household and caregivers are at an increased risk. For the same reason, so are college students who live in dormitories.
Can the Meningococcal Vaccine Cause Meningococcal Disease?
The short answer is no. There are actually four meningococcal vaccines licensed in the U.S. Noneof the vaccines contains live bacteria.
The vaccines contain antigens -- substances that trigger the body's immune system and cause it to make antibodies. These antibodies then protect the body by attacking and killing the bacteria if it should invade your system.
The first vaccine -- meningococcal polysaccharide vaccine or MPSV4 -- was approved in 1978. It's made with the antigens contained in the outer polysaccharide or sugar capsule that surrounds the bacterium.
The meningococcal conjugate vaccine or MCV4 was approved in 2005. It uses antigens taken from the polysaccharide capsule and then bound to a separate protein that targets the body's immune cells. This makes it easier for the body's immune system to see and recognize the antigens.
One type of MCV4, Menveo, is licensed for use in people aged 2 to 55. Another version, Menactra, is approved for those 9 months to 55 years old. MPSV4 is the only vaccine licensed for use in people over 55 as well as people 2 to 55. Both vaccines protect against four types of meningococcal disease.
In 2015, two serogroup B vaccines were given approval and protect against the other two forms of meningococcal disease. MenB-FHpb or Trumenba was approved for a three dose schedule, while MenB-4C Bexsero is approved for two doses. Both vaccines have proven effective is protecting those aged 10-25, but have also been found to be useful for older patients.
Are Both Meningococcal Vaccines Equally Effective?
The MCV4, MPSV4 and MenB vaccines are about 85-90% effective in preventing meningococcal disease. There are actually several types of N meningitidis -- the bacterium that causes meningococcal disease, five of which are common in the U.S. These vaccines together protect against all five of these strains.
MCV4 has not been available long enough to compare the long-term effectiveness of the two vaccines. But most experts think that MCV4 provides better, longer-lasting protection.
Is It Possible to Get the Vaccine and Still Get Meningitis?
Because the vaccines do not protect against all causes of meningitis, it is still possible that someone could receive the vaccine and still get meningitis from a different strain not protected by the vaccine. But the risk of contracting meningococcal meningitis is significantly lower after the vaccine.
There are other causes of meningitis that are preventable. Vaccines like the Hib vaccine and the pneumococcal vaccine are also very effective at protecting against other causes of meningitis and should be included as part of a routine childhood vaccination schedule. Check with your doctor and your children's doctor to make sure that you and your family are protected against meningitis, as well as other serious illnesses.
Who Should Get Which Meningococcal Vaccine and When?
Although MCV4 is the preferred vaccine for most people, if it is not available when it's time for the vaccination, MPSV4 can be used.
Routine immunization with the meningococcal vaccine MCV4 is recommended for children aged 11 or 12, with a booster to be given between ages 16 and 18. Vaccinations are also recommended for the following groups:
- College freshmen living in a dorm
- Military recruits
- Someone who has a damaged spleen
- Someone whose spleen has been removed
- Someone with terminal complement component deficiency (an immune system problem)
- Microbiologists who are routinely exposed to meningococcal bacteria
- Someone traveling to or residing in a country where the disease is common
- Someone who has been exposed to meningitis
Preteens who are 11 and 12 usually have the shot at their 11- or 12-year-old checkup. An appointment should be made to get the shot for teenagers who did not have it when they were 11 or 12.
The vaccine may be given to pregnant women. However, since MCV4 and MenB are newer vaccines, there is limited data about their effect on pregnant women. They should only be used if clearly needed.
Anyone who is allergic to any component used in the vaccine should not get the vaccine. It's important to tell your doctor about all your allergies.
People with mild illness such as a cold or congestion can usually get the vaccine. But people who are moderately or severely ill at the time of vaccine administration should wait until they recover.
Anyone with a history of Guillain-Barre syndrome should discuss their history with their doctor before getting a vaccination.
What Are the Side Effects From the Meningococcal Vaccines?
With any vaccine, there is the potential of a severe allergic reaction within a few minutes to a few hours after the shot. But the likelihood that the meningococcal vaccines would cause a severe reaction is extremely slight.
About one out of every two people who get the shot experience mild reactions such as redness or a mild pain where the shot was given. Those usually go away in one to two days. A small percentage of people develop a mild fever.
There have been reports that a few people have been diagnosed with Guillain-Barre syndrome (GBS) after receiving MCV4. But experts say it occurs so rarely that it's not possible to tell if it's related to the vaccine or coincidental.
What Are the Risks of GBS With the MCV4 Vaccine?
Between 2005 and 2012, more than 18 million doses of MCV4 were distributed. It's uncertain how many of those have actually been given. In that same time period, there have been 99 confirmed cases of GBS, a serious nervous system disorder, reported within six weeks of the vaccine being taken. There is not enough data at this time to tell whether or not the vaccine was a factor. But analysis of the data suggests that the incidence of GBS is no higher for people receiving the vaccine than the incidence of GBS in the general population.
Still, the timing of the onset of symptoms has raised concern. The CDC is continuing to study the issue and has recommended that people be told about the study when they are considering the vaccine. The current opinion is that even if there is a slight increase in the risk of GBS, it's significantly outweighed by the risk of meningococcal disease without the vaccine.