A somatic antigen vaccine for the prevention of meningococcal cerebrospinal meningitis.

Meningococcal cerebrospinal meningitis is an important public health problem in certain parts of the world-notably in Africa between the Sahara and the equator-and efforts are being made to control the disease by active immunization. To this end, the Laboratory of Hygiene of the Department of National Health and Welfare of Canada has undertaken studies on the development of lysed, clear (somatic antigen) vaccines, the method of preparation of which is described in this paper.Three Group A strains of Neisseria meningitidis have been used, two of them isolated from cases in the area of Africa for which the vaccines are intended. The vaccines have successfully passed stringent safety tests, and preliminary limited studies in the epidemic area have indicated that they are relatively reaction-free in man. They have been found effective in protecting mice against challenge with a wide range of Group A strains of N. meningitidis as well as with some Group B, C and D strains, but the authors stress that the value of these vaccines for man will remain uncertain until satisfactory field trials can be carried out.