The purpose of this report was to ascertain the growth of protective antibodies in the serum of persons vaccinated with various serums. The level of these antibodies can be determined on mice or chick embryos. Two considerations favored the choice of embryos the much smaller amount of serum needed to make this test, and the greater objectivity of the test, resulting from the total humoral neutrality of the embryo itself.
Trans. of Przeglad Epidemiologiczny (Poland) v17 p67-69 1963. See also Part 3, AD84 843.