How effective is the meningococcal vaccine?

70-85% Depending upon which vaccine strain you are talking about, a single dose will create a seroresponse (or documented immune response) roughly 70-85% of the time. When used broadly, this will translate to an 85-100% efficacy in reducing infection rates in kids. Currently, the CDC now recommends a second dose - after the second there is almost 95-100% response with very high titers.
See below. This vaccine is about 90% effective in preventing menigococcal disease.

Related Questions

Is the meningococcal vaccine a three shot?

No. The recommendations are complicated, but none recommend a three dose series. Some children and adults need two doses as part of their primary vaccination series, others need just one. If an individual remains at risk for exposure to meningococcus, then a booster every 5 years is recommended.
No it is one shot. It is a single shot but you may need booster to keep immunity.

Who should not receive meningococcal vaccine?

Almost No-one. The only contraindications are if you have had an allergic reaction to the Meningococcal vaccine previously or if you are moderately to severely ill.
Only allergic. It is a killed/protein vaccine, so it cannot cause the condition, so basically unless allergic to the vaccine or eggs (usually produced utilizing egg proteins), then should get it. Your dr can provide specific counsel.

What metals does the meningococcal vaccine have?

All but 1 have none. Mcv4-menactra, menveo, menhibrix, and single dose menomune-a/c/y/w-135 all have no metal ingredients. Only the multi dose vial of menomune-a/c/y/w-135 has thimerosal preservative--mercury is considered a metal. Also, unlike popular press, one cannot get meningitis from these vaccines--they only have killed partial particles.

How many doses of meningococcal vaccine are needed

1 or 2. Well, there is a small discrepancy right now. The cdc, the people who recommend how to get shots, recommends that kids 11-18 need two doses. One at 11yo and one aft 16yo. But, the fda has not approved either brand, Menveo or menactra, to be given that way. Both are only approved as a one dose vaccine. This will clear up soon and every kid will get 2 doses, and you can do that now off fda label.
How old are you? One usually given in childhood; then second end of high school / @ college entry. Lasts 10-15 years, so if working with high risk populations (kids/teens/young adults), could get booster in 35-ish age.

What are some dangers of the meningococcal vaccine?

Allergic reaction/f. Like with any vaccine one can get mild to severe allergic reaction to Meningococcal vaccine, mild redness or slight pain at the site of injection, a small percentage develope fever which goes awau in 48 hours severe ractions are very rare and most reactions are mold there have been some reports of guillen barre syndrome but it is so rare that no one is convinced that vaccine is causing it.

Does the meningococcal vaccine include a three shot series?

No. Not as of now. The Meningococcal vaccine Menveo (merck) is fda approved as a one dose series for 11-18year olds, and aged 2-55years if high risk for disease. Menactra is approved as a one dose series for the same and as a two dose series for kids 9-12 months. Possibly one or both will be approved soon for infants 0-24 months as a 2 or 3 dose series, but not yet.
No. Dr degraw's answer is correct, but recently there is a formal recommendation for a booster shot to be given in teens 5 years or so after the first vaccination.