A novel approach using an attenuated recombinant vaccinia virus to test the antipoxviral effects of handsoaps

Evidence indicates an increase in nosocomial and household infections due t o viruses (Jeffries, D.J., 1995. Viral hazards to and from health care work ers. J. Hosp. Infect. 30, 140-155). An antiviral assay was developed for ev aluating efficiency of handsoaps at inactivating cell-free and cell-associa ted virus. A recombinant vaccinia virus, lacking a virulence factor (Isaacs , S.N., Kotwal, G.J., Moss, B., 1992. Vaccinia virus complement-control pro tein prevents antibody-dependent complement-enhanced neutralization of infe ctivity and contributes to virulence. Proc. Natl. Acad. Sci. USA 89, 628-63 2), whose construction was described earlier (Kotwal, G.J., Isaacs, S.N., M cKenzie, R., Frank, M.M., Moss, B., 1990. Inhibition of the complement casc ade by the major secretory protein of vaccinia virus. Science 250, 827-830) , was used as the representative poxvirus. Two antibacterial handsoaps, one surgical handsoap, one moisturizing handsoap, and a sanitizing agent were tested. An aliquot of the virus was mixed and incubated with soap, then tit rated onto BSC-1 cells for incubation at 37 degrees C for 48 h. The soaps' effect on cell-associated virus was tested similarly. The antibacterial soa ps inactivated all cell-free virus in 1 min. The surgical soap was effectiv e with a 5-min incubation, None of the soaps eliminated all of the cell-ass ociated virus in 1 min. This safe and reproducible assay seems efficient to establish the comparative efficacy of household and surgical soaps. (C) 20 00 Elsevier Science B.V. All rights reserved.