Isoimmune blood group antibodies in cattle after the use of a blood vaccine.

A total of 100 animals were inoculated twice within 21 days with the Onderstepoort babesiosis vaccine. High blood group antibody titres were recorded, especially after the second inoculation. The possibility is discussed of neonatal isoerythrolysis occuring after vaccination as a result of maternal isoimmune blood group antibodies gaining access to the circulation of the offspring which inherited the corresponding blood group factors from its size.