The vaccine commonly used to prevent Neisseria meningitidis infection/Meningococcal Disease is a conjugated polysaccharide vaccine.
One type of vaccine commonly used to prevent against infection/disease by encapsulated bacteria is a conjugated polysaccharide vaccine. These vaccines pair a weakly immunogenic bacterial polysaccharide with a strongly immunogenic protein such as a toxoid or an outer membrane protein. By coupling the two, a stronger immune response is initiated against either the polysaccharide alone or the protein alone. This type of vaccine is also licensed for prevention against Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae.
Kimmel et al. reviewed the prevention of meningococcal disease and reported that adolescents and young adults have a higher incidence and a higher risk of mortality when compared to other populations. This is the basis for recommendations that vaccines be given at age 11-12, those entering high school, and college freshmen living in dormitories.
Erlich et al. report on vaccination specifics of meningococcus which has a high efficacy in prevention of the disease. As a result, the incidence of meningococcal disease has decreased in recent years. The circulating antibodies produced with vaccination do not remain high and require a booster. Unfortunately, many adolescents remain unvaccinated and susceptible to this preventable disease.
Illustration A depicts a gram stain of N. meningitidis. Note the gram negative diplococci.
Answers 1: An example of a live, attenuated vaccine is the varicella vaccine.
Answer 2: Examples of killed, inactivated vaccines are Salk polio, influenza, and pertussis.
Answer 3: An example of a Toxoid vaccine is the tetanus vaccine.
Answers 1, 2 and 3 are all incorrect because they refer to vaccine types that are not used against Meningococcal disease. Polysaccharide would have been another correct choice.
Answer 5: Killed, attenuated vaccines do not exist. Attenuated by definition means the viral or bacterial agent is viable but not able to cause significant disease. In essence, it is weakened and not killed.
Kimmel SR. Prevention of meningococcal disease. Am Fam Physician. 2005 Nov 15;72(10):2049-56. Review. PubMed PMID: 16342836.
PMID:16342836 (Link to Abstract)
Erlich KS, Congeni BL. Importance of circulating antibodies in protection against meningococcal disease. Hum Vaccin Immunother. 2012 Aug;8(8):1029-35.
PMID:22854672 (Link to Abstract)
USMLE World Step 1 QBank Question #1764. Copyright © USMLEWorld, LLC 2012