MeNZB

Key takeaways

MeNZB belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect MeNZB to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of MeNZB from memory before moving on to harder problems.

Reference excerpt

MeNZB was a vaccine against a specific strain of group B meningococcus, used to control an epidemic of meningococcal disease in New Zealand. Most people are able to carry the meningococcus bacteria safely with no ill effects. However, meningococcal disease can cause meningitis and sepsis, 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). People who have been fully immunised may still carry the meningococcus bacteria and may still contract meningococcal disease.

Components Each dose is 0.5 ml and contains:

25 mcg of outer membrane vesicles from the Neisseria meningitidis group B strain NZ98/254. 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. 1.65 mg of aluminium hydroxide (an adjuvant). The immune system will normally not mount an immune response to the outer membrane vesicles if they are presented alone. The presence of the adjuvant forces the immune system to respond to the membrane vesicles by acting to prevent their breakdown and elimination, while causing local tissue damage to provoke the desired immune reaction. histidine (to stabilise the pH). 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. normal saline. 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.

Impact Since its introduction in 2004 the vaccine has had a dramatic impact on the meningitis epidemic began in 1991. Between 2004 and 2006 New Zealand offered free MeNZB vaccination to anyone under the age of 20. Routine immunisation for babies and preschoolers continued until June 2008. The last phase of this programme, immunisation for people with a high medical risk, ended in March 2011. Reasons given for this halt of the programme include that the epidemic was coming to an end, and that immune protection given by the vaccine is only short-term. The primary analysis estimated MeNZB to have an effectiveness of 77% after 3 doses and a mean follow-up time of 3.2 years. As N. gonorrhoeae and N. meningitidis are closely related bacteria and have 80–90% homology in their genetic sequences some cross-protection by meningococcal vaccines against N. gonorrhoeae infections is plausible. A study published in 2017 showed that MeNZB vaccine provided a partial protection against Gonorrhea. The vaccine efficiency was calculated to be 31%.

References

External links New Zealand Ministry of Health immunisation information. Immunisation Advisory Centre, University of Auckland. Evidence based information on meningococcal disease and MeNZB vaccine. MeNZB information from vaccine manufacturer Chiron's website. News article: The Meningococcal Gold Rush – An untested and experimental vaccine New Zealand Ministry of Health response to article linked above Press release: Minister Misleads Kim Hill and Public on MeNZB Press release: Increased Vaccine Risk in Pre-Schoolers – Explain Response to press release linked above: Unethical anti-science scaremongering Press release: MeNZB Vaccination Campaign Starts Derailing News article: Officials praise meningococcal B vaccine coverage TV news item covering vaccination campaign Ruling on complaint about TV news item covering vaccination campaign (linked above) News article: Adverts inform parents on vaccine Press release: MeNZB Early Indications Graph

Worked examples

Example 1 — a first encounter with MeNZB

Start with the simplest possible case. Write down what MeNZB claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to MeNZB before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about MeNZB ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of MeNZB

In research: MeNZB appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses MeNZB in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: MeNZB is common in secondary-school and first-year university syllabi. It links to neighbouring topics Meningococcal vaccines, Subunit vaccines, so understanding it makes those chapters shorter.
In everyday life: Look for MeNZB outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study MeNZB in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what MeNZB means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain MeNZB out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is MeNZB in simple terms?

MeNZB was a vaccine against a specific strain of group B meningococcus, used to control an epidemic of meningococcal disease in New Zealand. Most people are able to carry the meningococcus bacteria safely with no ill effects.

Why does MeNZB matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study MeNZB?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on MeNZB.