Activity of colloidal silver preparations towards smallpox virus

The bactericidal properties of silver have been widely known for a long time. However we have found no work devoted to the investigation of its antiviral properties (except on influenza virus). The present study is the first of a series of investigations on the antiviral activity of preparations containing colloidal silver. The LIVP strain of smallpox vaccine (SPV) was chosen as the model. EXPERIMENTAL Tris-phosphate buffers of pH 7.2 and 8.9 were used as the background solution for preparing test solutions of SPV. The final concentration of viral particles in the test solution was brought to i-i0 s BAU/ml (Ig).* The test solution was used at 18~ Assessment of the antiviral properties of the colloidal silver solutions was carried out in vitro. Aqueous solutions (0.05%) of collargol and protargol, medicinal preparations of colloidal silver, were used in the experiments. A suspension of SPV was added to these solutions to a final concentration of l0 s BAU/ml (ig). Test samples were withdrawn after 60 min exposure for the assessment of results. Quantitative assessment of the SPV in the samples was carried out immediately after the end of the exposure on the chorio-allantoic membrane of 11-13 day old chick embryos by the usual method. The virucidal action of colloidal silver solutions was investigated using the serial dilution method.