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When did the meningococcal vaccine become available?
The first meningococcal vaccine in the United States was licensed in 1974 and was effective against only one of the five major subtypes of meningococcus.
A meningococcal polysaccharide vaccine or "MPSV" (Menomune by sanofi pasteur) was licensed in 1981 for persons ages 2 years and older. It protects against four subtypes of meningococcus - A, C, Y, and W-135.
A meningococcal conjugate vaccine or "MCV" (Menactra by sanofi pasteur) was licensed in 2005. It also protects against the A, C, Y and W-135 subtypes. MCV is expected to give better, longer-lasting protection than the polysaccharide vaccine. It is licensed for use in persons 11-55 years of age.
Unfortunately, no vaccine protects against subtype B which causes about one third of all the meningococcus cases in the United States. In 2001, 65% of cases in infants age one year or younger were caused by subtype B.
What kind of vaccines are they?
The MPSV vaccine is made from the outer polysaccharide capsule (sugar coat) of the meningococcal bacteria. The vaccine does not contain live bacteria. The MCV vaccine contains Neisseria meningitidis serogroup A, C, Y and W-135 capsular polysaccharide antigens individually conjugated to diphtheria toxoid protein. The vaccine does not contain live bacteria.
How is this vaccine given?
The MPSV vaccine is given as an injection into the fat of the arm. The MCV vaccine is given in the muscle.
Who should get the meningococcal vaccine?
MCV is recommended for all children at their routine preadolescent check-up at 11-12 years of age. For those who never got a dose previously, a dose is recommended at high school entry or at about age 15 years.
Any other adolescent or teen who wants to decrease their risk of meningococcal disease can also get the vaccine.
Vaccination is recommended for other people at increased risk of meningococcal disease; this includes:
- · College freshmen living in dormitories.
- · Individuals who have a damaged or missing spleen.
- · Persons with terminal complement component deficiency (an immune system disorder).
- · Persons working with meningococcus bacteria in laboratories.
- · Travelers to certain countries in sub-Saharan Africa as well to other countries for which meningococcal vaccine is recommended.
- · U.S. military recruits.
- · Anyone who might have been exposed to meningitis during an outbreak.
MCV is the preferred vaccine for persons ages 11 through 55 years in these risk groups, but MPSV can be used if MCV is not available. MPSV should be used for children 2-10 years old and adults over 55, who have risk factors for the disease.
Should college students be vaccinated against meningococcal disease?
College freshmen, especially those living in dormitories, are at an increased risk of meningococcal disease relative to other persons their age. The MCV vaccine is recommended for college freshmen who plan to live in dormitories. Some schools now require incoming freshmen and others to be vaccinated. The vaccine may be available from the college health service.
Although the risk for meningococcal disease among non-freshmen college students is similar to that of the general population of the same age, there is no medical reason that other students who wish to decrease their risk of meningococcal disease cannot receive the vaccine.
How many doses of meningococcal vaccine are needed?
Persons with risk factors who are either age two through nine years or older than 55 years should get one dose of MPSV. An additional dose is recommended if they remain at risk, such as people without a spleen or those who travel repeatedly to parts of Africa. If MCV is given, no additional doses are recommended at this time, even for people who remain at high risk.
Under special circumstances, MPSV may be recommended for children ages three months to two years. These children should get two doses, three months apart.
Should individuals who received MPSV vaccine in the past get a dose of MCV?
The current recommendation is only to revaccinate with MCV if it has been at least 5 years since the MPSV dose and if the person is in a high-risk category (e.g., college freshman living in a dorm).
How safe is this vaccine?
Both meningococcal vaccines are very safe. Polysaccharide (sugar) meningococcal vaccines have been used extensively in mass vaccination programs, such as those conducted by the military.
What are the side effects of this vaccine?
Up to about half of people who get meningococcal vaccines have mild side effects, such as redness or pain where the shot was given. These symptoms usually last for one or two days and are more common after MCV than after MPSV.
A small percentage of people who receive the vaccine develop a fever. Severe reactions, such as a serious allergic reaction, are very rare.
How effective is this vaccine?
The MPSV vaccine is 85 percent to 100 percent effective at preventing infection from the subtypes of meningococcus found in the vaccine (A, C, Y, and W-135). However, the vaccine does not protect against subtype B meningococcus. The vaccine is not licensed and not effective in children younger than two years of age.
Based on results of laboratory studies, MCV is believed to be as effective as MPSV, and to have a longer duration of immunity.
Who should not receive meningococcal vaccine?
- · Persons who have had a serious allergic reaction to a previous dose of either meningococcal vaccine or to one of the vaccine components.
- · Persons who are moderately or severely ill.
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