Statement on meningococcal vaccination for travellers

Canadian Medical Association Journal 1995; 153: 303-305
Health Canada, 1995
Reproduced with permission of the Minister of Supply and Services Canada, 1996
Copies of the original report (Canada Communicable Disease Report 1994; 21: 25-29) can be obtained from Eleanor Paulson, editor, CCDR, Bureau of Communicable Disease Epidemiology, Laboratory Centre for Disease Control, Tunney's Pasture, Ottawa, ON K1A 0L2.
Meningococcal infection is a severe disease with a case-fatality rate of 15% or more. It occurs sporadically worldwide and in focal epidemics. Spread of the organism is by the respiratory route. Certain areas of the world have predictable periods of meningococcal disease activity that may pose a risk to international travellers or Canadians working abroad.

Because transmission occurs at variable rates, exposure risk even within the known geographic areas of meningococcal disease activity can be very difficult to predict. The place and duration of exposure are not the only factors to consider. Climatic conditions, which vary from year to year, have a major impact on the intensity of risk. The setting of exposure, such as crowded, intimate or institutional living quarters within a disease activity area is also important. In addition, the health status of the traveller must be considered. Age is a major determinant of disease risk. Of recent cases in Canada, 29.1% occurred in infants under 2 years of age, 42.4% in children aged 2 to 19 years, and 28.6% in people over 19 years of age (Laboratory Centre for Disease Control [LCDC], Ottawa, unpublished data, 1995). Similar data have been reported in the United States.[1] A history of splenectomy and compromised immune function are also important risk factors.

Statement 1

Epidemiology of meningococcal disease in developing nations

The epidemiologic pattern of meningococcal infection in developing nations where the disease is active indicates that children are at the greatest risk of disease and that the peak incidence may occur in those under 2 years of age. In addition, data indicate that there is an appreciable risk of disease in adulthood (strength of statement: category A; quality of evidence: grade III[2]).

The areas of the world where meningococcal meningitis is traditionally endemic include regions of sub-Saharan Africa (see list at the end of this article). Disease occurrence in these areas is seasonal and can greatly exceed that found in other parts of the world.

In addition to areas with predictable meningococcal activity, areas of new activity are identified in frequent updates published by the LCDC; these updates should be used to assess the need for vaccination. Before recommending vaccination against meningococcal disease, the physician must exercise considerable clinical judgement in the assessment of the international traveller, taking into account potential geographic exposure, health status and planned activities.

The meningococcal polysaccharide vaccines licensed in Canada are safe, immunogenic and include the serogroups A and C, which are most commonly associated with epidemics of the disease. They should be considered for "at-risk" individuals who are in, or who will be in, a zone of increased activity of meningococcal disease caused by one of the serogroups covered by the vaccine.

Statement 2

Age-specific immune response to meningococcal vaccines

In studies involving children aged 3 to 5 months, immunogenicity against group A meningococcal polysaccharide 3 months after administration of two doses of monovalent vaccine was poor: serum antibody levels for group A meningococcal polysaccharide were found to be less than 2 µg/mL in 36% of subjects and 1 µg/mL in 60%.[3,4] Similarly, children vaccinated at 3, 7 and 12 months of age with either A or C vaccine or both demonstrated rapidly declining antibody levels between the ages of 13 and 24 months. A more dramatic decline in group C antibody levels was observed[4,5] (strength of statement: category A; quality of evidence: grade II).

In a more recent report on a vaccination program in Ottawa, antibody levels were measured in 50 children aged 6 to 12 months. At 1 month after vaccination a very modest antibody response to group A was seen, i.e., a rise from 0.13 µg/mL (before vaccination) to 1.58 µg/mL (after vaccination). In addition, the researchers reported a poor correlation in bactericidal activity and antibody levels to group C in very young children[5,6] (strength of statement: category A; quality of evidence: grade II).

Statement 3

Vaccine efficacy

Vaccine efficacy against group A meningococcal disease declines rapidly in children given a single dose of vaccine at less than 4 years of age. (Vaccine efficacy at 1, 2 and 3 years after vaccination is 100%, 52% and 8%, respectively.) Similarly poor responses to polysaccharide A have been shown with quadrivalent-combined vaccine in children aged 2 to 8 years at 1-year follow-up[4,6,7] (strength of statement: category A; quality of evidence: grade II).

Statement 4

Timing of primary vaccination and the need for booster doses

Giving a booster dose of vaccine against group A and C meningococcal disease after primary vaccination (with one or two doses of either A or C vaccine) has been studied for bivalent vaccine A + C given to healthy North American children aged 2 and 5.5 years[4,8] (strength of statement: category A; quality of evidence: grade II).

Primary vaccination of African children between the ages of 1 and 4 years with a single dose of bivalent vaccine A + C showed a decline of antibody levels to group A at 2 and 5 years after vaccination. This decline was not influenced by a booster dose of vaccine given 2 years after vaccination[2,8] (strength of statement: category A; quality of evidence: grade II).

The primary vaccination schedule should follow the recommendations contained in the Canadian Immunization Guide.[9] Protective immunity is established about 15 days after vaccination and is estimated to last for at least 3 to 5 years in adults.

The following individuals should be considered for vaccination when they visit countries with an increased risk of meningococcal infection.

  1. Adolescents and children who are in, or will be travelling to, an area of epidemic meningococcal activity. Serogroup A vaccine may be less than fully effective in children 6 to 11 months of age. Serogroup C vaccine has not been shown to be effective in children under 2 years of age.
  2. Individuals working in hospitals, health care, field epidemiology, research, international aid or refugee camps in areas of epidemic meningococcal activity.
  3. Individuals who will be working or living in the "traditional" endemic meningococcal areas of the world, (i.e., sub-Saharan Africa).
  4. Individuals who will be involved in activities that the local health authority or government would consider to present a risk for acquiring meningococcal disease.
  5. Individuals such as flight attendants and cabin crews, military or intelligence personnel who travel extensively and unpredictably.
  6. Individuals making contact with people with traditional lifestyles in rural parts of endemic areas.
  7. Pilgrims to Mecca for the annual Hajj or 'Umra. Saudi Arabia requires evidence of vaccination against meningococcal meningitis for these individuals.

Vaccination is not recommended for people making short-term business or holiday trips to areas of heightened meningococcal activity who will have little contact with or exposure to local populations in crowded conditions.

The following countries have frequent epidemics of meningococcal meningitis, mostly of serotype A and especially during the dry season (December through June). These countries are in what is known as the sub-Saharan African meningococcal meningitis belt: Benin, Burkina Faso, Cameroon, Chad, Central African Republic, Côte d'Ivoire, Djibouti, Ethiopia, Gambia, Ghana, Guinea, Guinea-Bissau, Mali, Niger, Nigeria, Rwanda, Senegal, Somalia, Sudan, Togo.

In the recent past, the following countries reported epidemics or significant outbreaks of meningococcal meningitis: Brazil (serotype B), Burundi, Chile, Cuba, Haiti, India, Kenya, Malawi, Nepal, Tanzania and Uganda.

References

  1. Laboratory-based surveillance for meningococcal disease in selected areas, United States, 1989-1991. MMWR 1993; 42 (SS-2): 21-30
  2. Evidence-based medicine. Can Commun Dis Rep 1994; 20: 145-147 [also in CMAJ 1995; 152: 201-202]
  3. Peltola H, Makela PH, Kayhty H et al: Clinical efficacy of meningococcus group A capsular polysaccharide vaccine in children three months to five years of age. N Engl J Med 1977; 297: 686-691
  4. Gold R, Lepow ML, Goldschneider I et al: Kinetics of antibody production to group A and group C meningococcal polysaccharide vaccines administered during the first six years of life: prospects for routine immunization of infants and children. J Infect Dis 1979; 140: 690-697
  5. King J, MacDonald N, Ashton F et al: Immunogenicity of quadravalent meningococcal polysaccharide vaccine (MenomuneTM) during a mass vaccination campaign. [abstract 525] Pediatr Res 1993; 33: 90A
  6. Reingold AL, Broome CV, Hightower AW et al: Age-specific differences in duration of clinical protection after vaccination with meningococcal polysaccharide A vaccine. Lancet 1985; 2: 114-118
  7. Lepow ML, Beeler J, Randolph M et al: Reactivity and immunogenicity of a quadrivalent combined meningococcal polysaccharide vaccine in children. J Infect Dis 1986; 154: 1033-1036
  8. Ceesay S, Allen SJ, Menon A et al: Decline in meningococcal antibody levels in African children 5 years after vaccination and the lack of an effect of booster immunization. J Infect Dis 1993; 167: 1212-1216
  9. National Advisory Committee on Immunization: Canadian Immunization Guide, 4th ed (cat no H49-8/1993E), Health Canada in collaboration with the Canadian Medical Association, Ottawa, 1993: 78-81
Source: Committee to Advise on Tropical Medicine and Travel

Members: Dr. D.W. MacPherson (chairman), Dr. S. Dumas, Dr. G. Horsman (Advisory Committee on Epidemiology), Dr. J.S. Keystone, Dr. D. Lawee, Dr. J.D. MacLean, Dr. J. Robert, Dr. R. Saginur, Dr. D. Scheifele (National Advisory Committee on Immunization) and Mrs. R. Wilson (Canadian Universities Service Overseas). Ex-officio members: Dr. P. Percheson (Health Protection Branch [HPB], Health Canada), Dr. E. Gadd (HPB, Health Canada), Dr. S. Mohanna (Medical Services Branch, Health Canada), Dr. R. Nowak (Department of National Defence), Dr. M. Tipple (US Centers for Disease Control and Prevention), Dr. C.W.L. Jeanes (Secretary), Dr. J.S. Spika (Laboratory Centre for Disease Control [LCDC], Health Canada), Ms. S. Ladouceur (Advisory Committee Secretariat Officer), Dr. J. Losos (LCDC, Health Canada) and Mrs. S. Herman (secretary).

Disclaimer

This guideline is for reference and education only and is not intended to be a substitute for the advice of an appropriate health care professional or for independent research and judgement. The CMA relies on the source of the CPG to provide updates and to notify us if the guideline becomes outdated. The CMA assumes no responsibility or liability arising from any outdated information or from any error in or omission from the guideline or from the use of any information contained in it.
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