| Vaccine description | |
|---|---|
| Target disease | Neisseria meningitidis |
| Type | ? |
| Clinical data | |
| AHFS/Drugs.com | monograph |
| MedlinePlus | a607020 |
| Pregnancy cat. | ? |
| Legal status | ? |
| Identifiers | |
| ATC code | J07AH01 J07AH02 J07AH03 J07AH04 J07AH05 J07AH06 J07AH07 |
| (what is this?) (verify) |
|
Meningococcal vaccine is a vaccine used against Meningococcus, a bacterium that causes meningitis, meningococcemia, septicemia, and rarely carditis, septic arthritis, or pneumonia.[1]
Contents |
Neisseria meningitidis has 13 clinically significant serogroups. These are classified according to the antigenic structure of their polysaccharide capsule. Six serogroups, A, B, C, Y, W135 and X are responsible for virtually all cases of the disease in humans.
There are currently three vaccines available in the US to prevent meningococcal disease, all quadrivalent in nature, targeting serogroups A, C, W-135 and Y:
Mencevax (GlaxoSmithKline) and NmVac4-A/C/Y/W-135 (JN-International Medical Corporation) are used worldwide, but have not been licensed in the United States.
The first meningococcal conjugate vaccine (MCV4), Menactra, was licensed in the U.S. in 2005 by Sanofi Pasteur; Menveo, was licensed in 2010 by Novartis. Both MCV4 vaccines have been approved by the Food and Drug Administration (FDA) for people 2 through 55 years of age. In April 2011, Menactra received FDA approval for use in children as young as 9 months, although the Centers for Disease Control and Prevention (CDC) has not made recommendations for or against its use in children less than 2. [2]
Meningococcal polysaccharide vaccine (MPSV4), Menomune, has been available since the 1970s. It may be used if MCV4 is not available, and is the only meningococcal vaccine licensed for people older than 55. Information about who should receive the meningococcal vaccine is available from the CDC.[3]
The duration of immunity mediated by Menomune (MPSV4) is three years or less in children aged under 5 because it does not generate memory T cells.[4][5] Attempting to overcome this problem by repeated immunization results in a diminished not increased antibody response, so boosters are not recommended with this vaccine.[6][7] As with all polysaccharide vaccines, Menomune does not produce mucosal immunity, so people can still become colonised with virulent strains of meningococcus, and no herd immunity can develop.[8][9] For this reason, Menomune is suitable for travelers requiring short-term protection, but not for national public health prevention programs.
Menveo and Menactra contain the same antigens as Menomune, but the antigens are conjugated to a diphtheria-toxoid polysaccharide–protein complex, resulting in anticipated enhanced duration of protection, increased immunity with booster vaccinations, and effective herd immunity.
A study published in March 2006 comparing the two kinds of vaccines found that 76% of subjects still had passive protection three years after receiving MCV-4 (63% protective compared with controls), but only 49% has passive protection after receiving MSPV-4 (31% protective compared with controls).[10] As of 2010, there remains limited evidence that any of the current conjugate vaccines offer continued protection beyond three years; studies are ongoing to determine the actual duration of immunity, and the subsequent requirement of booster vaccinations. The CDC offers recommendations regarding who they feel should get booster vaccinations.[11][12]
A vaccine called MenAfriVac has been developed through a program called the Meningitis Vaccine Project and it is a good option for preventing meningitis group A infections.[13][14]
A vaccine for serogroup B was developed in Cuba in response to a large outbreak of meningitis B during the 1980s. The VA-MENGOC-BC vaccine proved safe and effective in randomized double-blind studies[15][16][17], but it was granted a license only for research purposes in the United States[18] as political differences limited cooperation between the two countries.[19]
Due to a similarly high prevalence of B-serotype meningitis in Norway between 1975 and 1985, Norwegian health authorities developed a vaccine specifically designed for Norwegian children and young adolescents. Clinical trials were discontinued after the vaccine was shown to cover only slightly more than 50% of all cases. Furthermore, lawsuits for damages were filed against the State of Norway by persons affected by serious adverse reactions. Information that the health authorities obtained during the vaccine development were subsequently passed on to Chiron (now a Novartis subsidiary), who developed a similar vaccine, MeNZB, for New Zealand.
The occurrence of serogroup X was reported in North America, Europe, Australia, and West Africa.[20] Current meningoccocal meningitis vaccine is not known to protect from serogroup X N. meningitidis disease.