About 1 in 20 children with meningitis caused by meningococcus and about 1 in 3 children with bloodstream infections (i.e., sepsis) caused by meningococcus will die from the infection. Death from sepsis can occur within 12 hours of the beginning of the illness. Meningococcus is one of the most rapid and overwhelming infectious diseases known to man.
- The disease
What is meningococcus?
The bacterium, Neisseria meningitidis, primarily targets children younger than 1 year of age. Because meningococcus is contagious, outbreaks can occur in childcare centers and schools. Cases also occur in high schools and on college campuses.
Meningococcus usually causes meningitis (inflammation of the lining of the brain) or sepsis (an infection of the bloodstream). Symptoms of meningitis include stiff neck, headache, fever and drowsiness. Symptoms of sepsis caused by meningococcus include fever, shock and coma. The disease is so rapid that a child can be perfectly well and, in a matter of only a few hours, be in a coma. For these reasons, meningococcal infections that occur in childcare centers, elementary schools or high schools often cause panic in the community. Every year about 800 to 1,500 people in the United States are infected with meningococcus and about 120 die. Meningococcus can also cause pneumonia and arthritis.
Consequences of meningococcal infection occur in about 12 of every 100 survivors and include limb amputation, skin grafting, hearing loss, seizures, kidney disease and mental retardation. About 10 of every 100 people infected with meningococcus will die from the disease. Immunization is the most effective way to reduce the incidence of death and permanent sequelae caused by meningococcus.
How do you catch meningococcal infection?
Usually meningococcal infection is acquired after intimate contact with an infected person. Intimate contact includes kissing, sharing food or beverages, or staying in the same house or room (including a classroom) for more than four hours a day.
Because smoking disrupts the lining of the throat, people who smoke are at increased risk of some infections, including pneumococcus and meningococcus. Both of these vaccine-preventable diseases can cause meningitis.
- The vaccine
How is the meningococcal vaccine made?
Meningococcal vaccine is similar to those for pneumococcus and Haemophilus influenzae type b (Hib) in that protection against disease occurs when one develops antibodies to the sugar (or polysaccharide) that coats the bacterium. A meningococcal vaccine, made using only the polysaccharide coating of meningococcus, has been available for several years. Unfortunately, children less than 2 years of age are not very good at making immune responses to the polysaccharide alone.
In order for young children to make an immune response, the polysaccharide must first be attached to a harmless protein. (see How Are Vaccines Made?). The polysaccharide attached to the protein is known as a conjugate vaccine. There are two conjugated meningococcal vaccines:
- One, available since 2005, can be given to people between 9 months and 55 years of age
- The second, available since February 2010, can be used in people between 2 and 55 years of age
In both vaccines, the polysaccharides have been stripped from the surface of four of the five different types of meningococcal bacteria that cause disease and each is linked to a harmless protein. The four conjugated polysaccharides are combined into a single shot.
Hib and pneumococcal vaccines have been easier to make than the meningococcal vaccine. The Hib vaccine was easier to make because there is only one type of Haemophilus influenzae that commonly causes severe disease in children (type b). The pneumococcal vaccine was easier to make than the meningococcal vaccine because, although there are about 90 different types of pneumococcus, most of the disease in children is caused by 13 types. Therefore, the pneumococcal vaccine contains these 13 different types of polysaccharides — each linked to a protein.
Although there are only five different types of meningococcus that commonly cause disease (types A, B, C, Y and W-135), it has been very difficult to make a vaccine that includes type B, and meningococcus type B accounts for two-thirds of meningococcal infections in infants and one-third of meningococcal infections in adolescents and adults. (Of note, two vaccines to prevent meningococcus type B were submitted for licensure to the Food and Drug Administration in 2014. Both are likely to be licensed for use in adolescents in 2015.)
Who should get the meningococcal vaccine?
The meningococcal vaccine is recommended for:
- Adolescents and teens 11 to 18 years old
- Children and adults without a spleen (see additional information about MenHibRix® below)
- Children and adults who lack a particular group of serum proteins, called complement proteins, that help the body fight infection (see additional information about MenHibRix® below)
- College freshmen living in dormitories
- People exposed to someone infected with meningococcus during an outbreak if the type of meningococcus is one contained in the vaccine (types A, C, Y or W-135)
- Children and adults who will be traveling to sub-Saharan Africa between December and June
- Military recruits
- Lab workers who work with the bacteria
Does the meningococcal vaccine have side effects?
The meningococcal vaccine may cause pain or tenderness where the shot is given. The vaccine does not have any serious side effects. Although a possible association with Guillian-Barre Syndrome (GBS) was investigated, no causal association was found.
- Other questions you might have
Is it true that more than one infection can cause meningitis?
Yes. Everyone has heard it on the news ─ the story of a local student infected with meningitis. Such a report inevitably results in many questions and a great amount of concern and even fear among families with children in the affected school.
There are some important considerations when this happens. First, it is important to remember that meningitis refers to an infection that has reached the lining of the brain and spinal cord. Second, it can be caused by viruses or bacteria (hence the reference to viral meningitis or bacterial meningitis).
Viral meningitis is often less severe than bacterial meningitis. Most, but not all, cases of bacterial meningitis can be prevented by vaccination. The bacteria most often associated with meningitis include meningococcus, pneumococcus, and Haemophilus influenzae type B (often referred to as Hib). Fortunately, by the age of 2, most children are fully immunized against pneumococcus and Hib and most adolescents are protected against meningococcus.
Should college students get the meningococcal vaccine?
The risk of meningococcal infection is highest in those younger than 1 year of age, and much lower in those between 4 and 15 years of age. At around 15 years of age the incidence of meningococcal disease again rises, although not nearly to the level that occurs in young children. So there is again an increased risk of meningococcal infection in adolescents and young adults. However, college freshmen who live in dormitories are five times more likely to get a meningococcal infection as compared with those who live off campus or don't attend college. Therefore, the meningococcal vaccine is recommended for all college freshmen living in dormitories.
Although adolescents and young adults are less likely than infants to be infected, they are more likely to die from the infection; therefore, it is a good idea for all adolescents to be immunized.
One of the children in my child's school got meningitis. Should my child get the meningococcal vaccine, take antibiotics, or do neither?
First, try to find out what bacteria caused the meningitis. This usually takes about 48 hours from the time that the diagnosis was first made. Remember, bacteria such as pneumococcus and Haemophilus influenzae type b (Hib) can also cause meningitis. If the bacterium was meningococcus, find out from public health officials whether it really was an outbreak of meningococcus and whether the outbreak was caused by one of the types contained in the vaccine (specifically, types A, C, Y or W-135). If so, your child should receive the meningococcal vaccine. By 2015, a new meningococcal vaccine that protects against type B will also likely be licensed for use.
In addition, antibiotics (such as rifampin, ceftriaxone or ciprofloxacin) should be used for all children who have come in close contact with someone who was infected. Close contact is defined as sharing a classroom for more than four hours a day, kissing or sharing food or beverages. Close contact in the week prior to the outbreak of meningococcus puts one at greatest risk of infection.
I’ve heard of a vaccine called MenHibRix®. What is it and who should get it?
A new vaccine, called MenHibRix®, was licensed in 2012; this vaccine protects against meningococcus and Haemophilus influenzae type b (Hib) and can be used in infants between 6 and 18 months of age. It is unique in that it is the first vaccine in which a part of the vaccine is recommended for all infants (Hib) and the other, only for high-risk groups (meningococcus).
The high-risk groups include those who lack a spleen or have a nonfunctional spleen, those with complement deficiencies or sickle cell disease, or those in communities with outbreaks of meningitis C or Y.
Because many infants who get meningococcal meningitis are infected with type B, and MenHibRix® only protects against types C and Y, the vaccine is not recommended for all infants. Parents can discuss whether the vaccine would be of benefit with their child’s doctor.
The case for and against Menhibrix® for individuals
Pros of Menhibrix®
- The vaccine will prevent about 1 of 4 cases and 2 to 4 deaths from meningitis in infants each year (about 44 cases and 2 to 4 deaths total)
- Infants are recommended to get the Hib vaccine anyway; this version will provide additional protection from some types of meningococcal disease.
- Vaccines for Children (VFC), a program for families who cannot afford vaccines, will cover the vaccine for qualified children.
Cons of Menhibrix®
- The vaccine will not prevent ALL cases of meningococcal meningitis in young children, including the most common type: type B.
- Infants will not be protected in the first 4 months of life, which is when they are most susceptible to meningococcal infections.
- All doctors may not carry this vaccine.
- Private insurance may or may not cover this vaccine.
- Relative risks and benefits
Do the benefits of the meningococcal vaccine outweigh its risks?
Each year about 800 to 1,500 people in the United States are infected with meningococcus and 120 die. About 400 survivors suffer permanent disabilities such as seizures, loss of limbs, kidney disease, deafness, skin grafting or mental retardation. The meningococcal vaccine does not cause any severe reactions. Therefore, the benefits of this vaccine outweigh its risks.
- Meningitis (inflammation of the lining of the brain). Symptoms can include stiff neck, headache, fever and drowsiness
- Sepsis (infection of the bloodstream). Symptoms can include fever, shock and coma
- Survivors can suffer limb amputation, skin grafting, hearing loss, seizures, kidney disease and mental retardation (12 of 100 people)
- Disease can be fatal (10 of 100 people)
- Pain or tenderness at the injection site
Plotkin SA, Orenstein W, and Offit PA. Meningococcal vaccines in Vaccines, 6th Edition, 2012, 388-418.