The safety and immunogenicity of vaccines are demonstrated before they are made available to doctors and the public. However, the protective activity against the disease for which a vaccine was designed can only be accurately measured in field trials.
Meningococcal meningitis epidemics are a major health problem in sub-saharan Africa where they account for thousands of deaths and cause morbidity in hundreds of thousands of people. Meningitis is caused by Neisseria meningitidis.
From October 1, 1990, until April 28, 1991, 13,578 cases of measles were reported in the urban community of Niamey, Niger.
Between February and October 1990, 18,276 cases of pellagra dermatitis (due to niacin deficiency) were reported among 285,942 Mozambican refugees in Malawi.
A seroprevalence survey of viral hepatitis was conducted in Bucharest, Romania, between April and July 1990 on a systematic sample of 1355 persons drawn from the general population and groups at higher risk of infection.
The three main metabolites of niacin have been measured in urine of 10 Mozambican women living in refugee camps in Malawi and displaying clinical symptoms of pellagra.
Between 1 February 1987 and 31 May 1988 an evaluation of a nutritional rehabilitation centre in Tahoua, Niger was conducted. Among the 381 children admitted to the centre, 61 (16%) had kwashiorkor and 347 (91.3%) were aged between 6 and 29 months.
