Antibodies against poliomyelitis and measles viruses in immunized and unimmunized children, Ghana 1976-78.

The serological response of children to two doses of live oral poliomyelitis vaccine (the first at age 3-8 months and the second at age 9-14 months) and to one dose of measles vaccine (at age 9-14 months) was determined in two regions of Ghana. The seroconversion rates after two doses of poliomyelitis vaccine were lower than expected-24% for poliovirus type 1, 60% for type 2, and 52% for type 3; 23% of the subjects were triple negative. A third dose of the vaccine increased the seroconversion rates to 36%, 73%, and 61% for poliovirus types 1, 2, and 3, respectively; the rate for triple negatives fell to 8%. In the course of the study it was found that there was an intensive circulation of wild polioviruses and that a high proportion of 3-8 month-old infants had maternal antibodies.The seroconversion rate following one dose of measles vaccine was about 90%, a response similar to that obtained in temperate climates. The two main conclusions drawn from the study were: (1) two doses of poliomyelitis vaccine are inadequate to provide protection against poliomyelitis in developing countries; and (2) in developing countries measles vaccine should be given as soon as possible after the age of 8 months.

A cold box for the transport and storage of vaccines.

A cold box capable of maintaining a temperature below +4 degrees C for 1 week was constructed and tested in the laboratory and under field conditions. Cooling is produced by commercial cold packs precooled in a deep-freeze or the freezing compartment of a refrigerator. The box can take approximately 3000 doses of vaccine and is simple, cheap and strong. It is primarily intended for storage of vaccines during field trips by vaccination teams, as an alternative to the refrigerator in regional and peripheral stores in the case of an electrical power failure, and for the delivery of vaccines from regional store to the district.