Meningococcal meningitis, caused by the bacterium Neisseria meningitidis, is a potentially fatal bacterial infection that afflicts between 2500 and 3000 persons in the United States each year. Approximately 10 percent of individuals who contract meningococcal disease will die. Of survivors, up to one in five suffer long-term permanent disabilities such as hearing loss, brain damage and limb amputations.
Advisory Committee on Immunization Practices (ACIP) currently recommends tetravalent or quadrivalent meningococcal conjugate vaccine for all 11 to 18 year olds and for persons aged 2 to 55 years who are at increased risk for meningococcal disease (CDC, 2007, 2010). The previous recommendations for meningococcal conjugate vaccine administration consisted of three cohorts: 11 to 12 year olds, adolescents entering high school (or 15 year olds), and other persons at increased risk for meningococcal disease, such as incoming college freshmen who would be living in dormitories. Because many adolescents do not see a doctor regularly, the expanded recommendations allow physicians to vaccinate adolescent patients whenever the opportunity to do so arises. The revised recommendations continue to emphasize that 11 to 12 year olds should receive the meningococcal conjugate vaccine at the 11 to 12 year old preventive care visit, along with other routine adolescent vaccinations. The ACIP has stated that their goal is routine vaccination of all adolescents beginning at age 11 years.
Adolescents and young adults in particular are at increased risk of contracting meningococcal meningitis because of certain lifestyle factors, such as crowded living conditions, moving to a new residence, attending a new school with students from geographically diverse areas, sharing beverages or utensils, going to bars, active or passive smoking, and irregular sleeping patterns (NMA, 2004). A CDC study of 83 reported meningitis cases in college students from September 1998 through May 1999, a rate of 1.4 cases per 100,000 freshmen, and 3.8 cases per 100,000 freshmen living in dormitories. The rate for all 18 to 22 year olds was 1 case per 100,000. According to the American College Health Association, between 100 and 125 college students get meningitis each year, and up to 10 die. Routine vaccination with meningococcal vaccine is also recommended for other populations at increased risk (i.e., military recruits, travelers to areas in which meningococcal disease is hyperendemic or epidemic, microbiologists who are routinely exposed to isolates of N. meningitidis, patients with anatomic or functional asplenia, and patients with terminal complement deficiency).
A conjugate vaccine is developed by attaching a polysaccharide antigen to a carrier protein in order to enhance the body's immune response to the vaccine. There are 2 meningococcal conjugate vaccines approved by the U.S. Food and Drug Administration (FDA): (i) meningococcal [Groups A, C, Y and W-135] polysaccharide diphtheria toxoid conjugate (Menactra, Sanofi Pasteur Inc., Swiftwater, PA), a purified meningococcal polysaccharide conjugated with an diphtheria toxin in order to prolong the immunogenic effect of the vaccine, and (ii) meningococcal [Groups A, C, Y, and W-135] oligosaccharide diphtheria CRM197 conjugate vaccine (Menveo, Novartis Vaccines and Diagnostics, Inc., Cambridge, MA), which is similar to Menactra. Whereas standard unconjugated meningitis vaccine (i.e., Menomune meningococcal [Groups A, C, Y and W-135] polysaccharide vaccine (Sanofi Pasteur Inc.) induces protective immunity for three to four years, conjugated meningitis vaccines are expected to provide protective immunity for up to eight years. Both Menactra and Menomune are currently approved by the U.S. Food and Drug Administration (FDA) for persons aged 2 years and older. The FDA approved Menactra for use in children aged 2 to 10 years on October 17, 2007, in addition to its prior approval for use in persons aged 11 to 55 years. Menveo was approved by the FDA on February 19, 2010 for use among persons aged 11 to 55 years. Previous ACIP recommendations called for vaccination with Menomune for children aged 2 - 10 years who are at increased risk for meningococcal disease. However, ACIP revised its recommendation during its October 24, 2007 meeting to state that meningococcal conjugate vaccine is preferable to meningococcal polysaccharide vaccine for vaccination of children aged 2 - 10 years who are at increased risk for meningococcal disease. Menactra and Menveo are administered intramuscularly, while Menomune is administered subcutaneously. Generally, only a single dose of meningococcal vaccine is indicated.
The Advisory Committee on Immunization Practices states that revaccination may be indicated for persons previously vaccinated with meningococcal vaccine who remain at high risk for infection (i.e., those with terminal complement deficiencies, with anatomic or functional asplenia, those infected with HIV, travelers to hyperendemic or epidemic areas), particularly for children who were first vaccinated when they were less than 4 years of age. According to the ACIP, such children should be considered for revaccination after 2 to 3 years if they remain at high risk. For children aged 2 -10 years who have previously received meningococcal polysaccharide vaccine and remain at increased risk for meningococcal disease, ACIP recommends vaccination with meningococcal conjugate vaccine at 3 years after receipt of meningococcal polysaccharide vaccine. Children who last received meningococcal polysaccharide vaccine more than 3 years ago and remain at risk for meningococcal disease should be vaccinated with meningococcal conjugate vaccine as soon as possible. In addition, adolescents 11 through 18 years of age who routinely received the meningococcal vaccine should receive a one-time booster dose 5 years later through age 21 years. Current evidence suggests that most adolescents are not protected for more than 5 years after vaccination, which is a shorter time frame than was thought when initial reccomendations were made (Hitt, 2010). Although the need for revaccination in adults has not been determined, antibody levels decline rapidly over 2-3 years after the polysaccharide vaccine is given, and if indications still exist for vaccination, revaccination may be considered within 3-5 years. Revaccination may be considered for college freshmen who were vaccinated more than 3-5 years earlier. Routine revaccination of college students who were vaccinated as freshmen is not indicated. Revaccination of military recruits is only indicated when military personnel are traveling to countries in which N. meningitidis is hyperendemic or epidemic.
In a single, randomized, modified double-blind, controlled study of healthy U.S. children aged 2 - 10 years that compared meningococcal conjugate vaccine with meningococcal polysaccharide vaccine, serum bactericidal antibody geometric mean titers against all four serogroups were significantly higher at both 28 days and 6 months after vaccination in the children who received meningococcal conjugate vaccine. In the same study, rates of most solicited local and systemic adverse events after vaccination with meningococcal conjugate vaccine were comparable to rates observed after vaccination with meningococcal polysaccharide vaccine (Pichichero, et al., 2005). It is anticipated that more data will become available within the next 5 years to guide recommendations on revaccination for persons who were previously vaccinated with meningococcal polysaccharide vaccine.
Meningococcal vaccine is contraindicated in persons with allergy to vaccine components and persons with acute, moderate or severe illnesses with or without fever. Persons with moderate or severe illness should be immunized as soon as they have recovered from the acute phase of the illness. Minor illnesses (e.g., upper respiratory tract infection, allergic rhinitis) with or without fever should not contraindicate the use of meningococcal vaccine.
The Surgical Infection Society (Howdieshell, et al., 2006) stated that there are limited data on the use of vaccines after injury. In particular, the recommendations that all persons (aged 2 to 64 years) who have undergone splenectomy, should receive 23-valent pneumococcal vaccine and meningococcal vaccine, with Haemophilus influenzae type B vaccine administered to high-risk patients as well are grade D (very low quality recommendations).
At its February 2008 meeting, the ACIP decided not to recommend routine vaccination of children aged 2 to10 years against meningococcal disease unless the child is at increased risk for the disease. The ACIP recommends routine vaccination against meningococcal disease for all persons aged 11 to 18 years followed by a one-time booster dose of the vaccine 5 years later through age 21 years and those persons aged 2 to 55 years who are at increased risk for meningococcal disease.
In 2011, the ACIP recommended use of meningococcal vaccine in infants age 9 through 23 months at increased risk of meningococcal diseases. The ACIP recommended that specific groups of children aged 9-23 months at increased risk for meningococcal disease receive a two-dose series of meningococcal vaccine taken 3 months apart:
- Infants needing protection prior to traveling or moving to an area where meningococcal disease is epidemic or highly endemic. Travelers can receive their two doses 2 months apart to accommodate travel schedules.
- Infants with complement component deficiencies such as C3, C5-9, properdin, factor H, and factor D deficiencies.
- Infants in a defined risk group for a community or institutional outbreak.
- Infants with HIV, if another indication for vaccination exists.
A two-dose series is required for any child whose first dose was received prior to their second birthday. Those who remain at risk for meningococcal disease should receive a booster dose 3 years after the primary series.
In October, 2012 ACIP voted to recommend that infants at increased risk for meningococcal disease should be vaccinated with 4 doses of HibMenCY at 2, 4, 6, and 12 through 15 months. These include infants with recognized persistent complement pathway deficiencies and infants who have anatomic or functional asplenia including sickle cell disease. HibMenCY can be used in infants ages 2 through 18 months who are in communities with serogroup C and Y meningococcal disease outbreaks. ACIP noted that meningococcal disease incidence has declined to historically low levels since the last peak in disease in the late 1990s and about 50 of infant cases are potentially preventable by available vaccines. The revised recommendations allow for the fact that the majority of infant cases are caused by a type of the bacteria that are not prevented by meningococcal vaccines. Also, the recommendations note that the majority of infant cases occur within the first 6 months of life, which is the time period before a vaccine would likely be able to protect the infant as 3 doses are needed (at 2, 4 and 6 months) to maximize the immune response.
At its October 2012 meeting, the ACIP voted to recommend vaccination against meningococcal serogroups C and Y for children aged 6 weeks through 18 months at increased risk for meningococcal disease. Meningococcal groups C and Y and Haemophilus b tetanus toxoid conjugate vaccine (Hib-MenCY-TT [MenHibrix, GlaxoSmithKline Biologicals]) is licensed for active immunization for prevention of invasive disease caused by Haemophilus influenzae type b (Hib) and meningococcal serogroups C and Y. Hib-MenCY-TT is not indicated for prevention of disease caused by meningococcal serogroup B, the most common serogroup causing disease in infants, or serogroups W135 or A, which are represented in quadrivalent meningococcal vaccines. Before licensure of Hib-MenCY-TT, no meningococcal conjugate vaccine was licensed for infants aged 2 through 8 months. MenACWY-D (Menactra, Sanofi Pasteur) is licensed as a 2-dose series for infants and toddlers aged 9 through 23 months, and MenACWY-D and MenACWY-CRM (Menveo, Novartis Vaccines) are licensed for persons aged 2 through 55 years as a single dose. These vaccines are recommended routinely for persons aged 11 through 18 years and persons aged 2 through 55 years at increased risk for meningococcal disease (and persons aged 9 months through 55 years for MenACWY-D) (CDC, 2013)
Hale and colleagues (2014) reviewed the immunogenicity and safety of Hib-MenCY-TT for infants and toddlers. Studies conducted in humans and limited to publication in English were identified through a MEDLINE (January 2000 to September 2013) search using the terms Hib-MenCY-TT, MenHibrix, and Haemophilus influenzae type b-Neisseria meningitidis serogroups C and Y tetanus toxoid conjugate vaccine. Clinical trial registries, Web sites, and reference citations from publications identified were reviewed for additional sources. Randomized controlled trials were included to evaluate the safety and immunogenicity of Hib-MenCY-TT. Epidemiological data and recommendations from the ACIP were also reviewed. Hib-MenCY-TT is available for primary vaccination of infants as a 4-dose series at 2, 4, 6, and 12 to 15 months of age. Hib-MenCY-TT has comparable immunogenicity to licensed Hib vaccines and produces high levels of N meningitidis antibodies against serogroups C and Y. The most common adverse events were pain and redness at the injection site, drowsiness, and irritability. The authors concluded that Hib-MenCY-TT has been demonstrated to be a safe and immunogenic vaccination for prevention of disease caused by N meningitidis serogroups C and Y and H influenzae type b in healthy infants and toddlers. Currently, the ACIP recommends the use of Hib-MenCY-TT specifically in high-risk infants aged 6 weeks to 18 months. Hib-MenCY-TT provides the first therapeutic option for vaccination of infants as young as 6 weeks of age who are at increased risk for meningococcal disease.
On August 1, 2014 the American Academy of Pediatrics (AAP) published updated recommendations on the use of meningococcal vaccines. These recommendations include a statement that an age-appropriate meningococcal conjugate vaccine is preferred to the meningococcal polysaccharide vaccine for the pediatric population, unless there is a contraindication for the meningococcal conjugate vaccine. The recommendations also state that adolescents should be routinely immunized at 11 to 12 years of age and given a booster dose at 16 years of age with a quadrivalent conjugated meningococcal vaccine; adolescents who received their first dose at age 13 to 15 years should receive a booster at age 16 to 18 years at least 8 weeks or up to 5 years after their first dose and adolescents who receive their first dose of meningococcal conjugate vaccine at or after 16 years of age do not need a booster dose. However, the recommendations also specify that unvaccinated or previously vaccinated first-year college students through age 21 years living in residence halls who received their last dose before their 16th birthday should receive a single dose of quadrivalent meningococcal conjugate vaccine (Committee on Infectious Diseases, 2014).
The August, 2014 AAP recommendations also list recommendations for individuals who are at increased risk for invasive meningococcal disease because of complement disease or asplenia indicating that they should receive a 2-dose primary series (MenACWY-CRM or Hib-MenCY-TT) between 2 to 18 months of age. The recommendations specify that MenACWY-D can be administered as a 2-dose series to infants 9 to 23 months of age in children with complement component deficiency and in infants up to 23 months of age after the fourth dose of the primary pneumococcal conjugate vaccine in children with asplenia. The AAP recommends that HIV-infected children 11 years of age or older should receive a 2-dose primary series 8 to 12 weeks apart with a single booster dose, consistent with healthy adolescent recommendations (Committee on Infectious Diseases, 2014).
For children greater than 2 years with persistent risk for meningogoccal disease due to asplenia or complement component deficiency, the primary series should be given including 2 doses of quadrivalent meningogoccal conjugate vaccine 8 to 12 weeks apart and for children 2 months to 6 years of age, a booster dose at 3 years after the primary series and every 5 years thereafter. For children 7 years of age and older as well as adoescents who are at persistent risk for meningogoccal disease and who received an initial meningogoccal vaccination on or after age 7, boosters of quadrivalent meningogoccal conjugate should be repeated every 5 years. Travelers to areas with high meningococcal endemicity should receive an age-appropriate meningococcal vaccine that includes serigroups A and W. Areas of high endemicity include the ‘meningitis belt’ of sub-Saharan Africa and the Hajj in Saudi Arabia (Committee on Infectious Diseases, 2014).
Hib-MenCY-TT may be co-administered with other routine infant vaccinations, including 13-valent pneumococcal conjugate vaccine. Hib-MenCY-TT should not be co-administered with other Hib-containing vaccines (Rubin et al, 2013).