1925 18 July 134/1 When injected together with virus-free extracts of tumours the virus produces a malignant new growth.
1946 26 Oct. 569/2 The great work of East Malling Research Station in raising and distributing virus-free clonal stocks.
2000 ‘Dr. K.’ x. 144 Once you have your anti-virus package, make sure that your machine is virus-free before installing the package.