MeNZB

From Wikipedia, the free encyclopedia

You have new messages (last change).

MeNZB is a vaccine against a specific strain of group B meningococcus, currently being used to control an epidemic of meningococcal disease in New Zealand. Meningococcal disease can cause meningitis and septicaemia, resulting in brain damage, failure of various organs, severe skin and soft-tissue damage, and death.

Immunisation with MeNZB requires three doses, administered approximately six weeks apart (except in newborns, who have them in conjunction with their 6-week, 3-month and 5-month injections).

Each dose is 0.5 ml and contains:

The vaccine does not contain any whole bacteria (alive or dead). The "outer membrane vesicles" it contains are a small part of the "skin" of the bacteria that let the immune system recognise and prepare for being infected with the real thing.

MeNZB vaccine does not contain any human, blood, or bovine (cow)products, egg products, neomycin or the preservative thiomersal (mercury). There are no live meningococcal bacteria in the vaccine and it is not possible to catch the disease or become a carrier of the disease from the vaccine.

The adjuvant is required to assist the immune system respond to the outer membrane vesicles in the vaccine. The body won't just accept an injection of outer membrane vesicles on their own (much like the postal service won't accept goods unless they are properly parcelled and addressed). The adjuvant is the "packaging" for the outer membrane vesicles.

The histidine pH buffer is to ensure the vaccine stays as close as possible to the pH of human body fluids. This is to ensure the immune system does not waste time trying to neutralise the vaccine instead of responding to the outer membrane vesicles.

The saline (sterile salt and water) is also like packaging. It is required so that all of the above can be dissolved into a solution that can be injected. It is the same salinity (saltiness) as normal human body fluid.

The antigen in MeNZB is prepared from B:4:P1.7b,4 (NZ 98/254 ) N. meningitidis strain, grown in a fermentor. The bacteria are grown in a synthetic culture medium containing sugar, essential amino acids and essential elements such as iron and potassium. The fermentation does not use bovine or porcine products. The cellular outer membranes are extracted with the detergent deoxycholate, which kills the bacteria. Outer membrane vesicles are purified out of the culture medium by ultracentrifugation, stabilised by histidine and then adsorbed to aluminium hydroxide Al(OH)3 as an adjuvant. Purification is achieved by ultrafiltration/diafiltration.

Since its introduction the vaccine has had a dramatic impact on the epidemic.

The vaccine, originally developed in Norway was discontinued in that country, due to the decline in the incidence of Meningococcal B disease during that epidemic.

[edit] References

    [edit] External links

    Retrieved from "http://en.wikipedia.org../../../m/e/n/MeNZB_a5ee.html"