A further study on measles vaccination in Nigerian children.

Measles is a serious disease in Nigeria, causing severe morbidity and appreciable mortality; it occurs almost exclusively in the pre-school child with a peak incidence in the second year of life. A safe measles vaccine would be of inestimable value both in that country and in other areas where the disease constitutes a grave menace. Studies using vaccines of the Enders Edmonston B type have shown that while these are efficient immunizing agents, severe reactions are too frequent to permit of their wide general use. In the quest for safer vaccines, and in accordance with the recommendations of a WHO Scientific Group, a field trial was undertaken in Western Nigeria in May 1964 to make direct comparisons of the antigenicity and reaction rates of three further-attenuated measles vaccines (Schwarz, Beckenham 20 and Beckenham 20/2) and Enders Edmonston B vaccine plus gamma-globulin. A control group was also included.Analysis of the clinical responses demonstrated that reactions were similar, and of minimal severity, in all vaccine groups. Neutralizing antibody responses showed that all the vaccines used were effective immunizing agents. From the point of view of ease of administration and expense, however, further-attenuated vaccines seem preferable to Enders Edmonston B administered with gamma-globulin.