Cultivation of second and third passage cells from Cercopithecus monkey kidneys in monolayer cultures

In order to further reduce the amount of monkeys used for production of inactivated poliovaccine without expensive investments, cultivation of second and third passage cells from Cercopithecus monkey kidneys in monolayer cultures has been attempted. Steep growth curves were obtained for all three passages. But the initial loss of cells in the first passage was a problem. Another one was the increased risk of contamination when higher passages of monolayer cultures were used. For practical purposes it may therefore be more favourable to use second instead of third passage cells.