De Ley M, Billiau A, De Somer P
J Gen Virol. 1978 Aug;40(2):455-8. doi: 10.1099/0022-1317-40-2-455.
The simultaneous occurrence of virus replication and of interferon production in Namalva lymphoblastoid cell cultures infected with measles virus has allowed the development of a semi-continuous production system yielding about 10(4) units of interferon for each 10(6) cells.