In 1969, three rubella virus strains were licensed in the U.S.: HPV-77 strain grown in dog-kidney culture (Rubelogen by Parke-Davis); HPV-77 grown in duck-embryo culture (Meruvax by Merck); and Cendehill strain grown in rabbit-kidney culture (Cendevax by RIT-SKF, and Lirubel and Lirutrin by Dow).