Imidlertid er effekten af levende skoldkoppevaccine (Oka/ Merck) og af MFR- vaccinen fremstillet af Merck & Co., Inc. påvist i en række undersøgelser.
However, the efficacy of Varicella Vaccine live (Oka/ Merck) and the measles, mumps, and rubella vaccine manufactured by Merck & Co., Inc. has been demonstrated in numerous studies.