Primary immunization of Rh-negative volunteers.

To determine the best method for the production of high-titre anti-D serum primary immunization was carried out in two groups of Rh-negative male volunteers with washed group O R(2)R(2) cells. The first group of six men were given 5 ml. of packed cells, and the second group of five men were given 0.5 ml. of packed cells, in each instance by intravenous injection. Only one individual in each group failed to develop anti-D following the primary inoculation, and it has been concluded that 0.5 ml. of packed R(2)R(2) cells is probably a satisfactory dose for this purpose.There was a delay of several weeks before anti-D could be shown to have developed. The initial antibodies which appeared in the serum comprised 7S gammaG immunoglobulins, with, in about half the cases, a minor 19S gammaM component.