摘要：For several years the routine smallpox revaccination procedures at a central inoculation unit were arranged to assess the relation between vaccine titre (pock count) and success. Calf lymph batches were applied, diluted and undiluted, over a log titre range of 7.0-9.8. The dose—effect relationship did not appear to fit a linear equation on a log-probit scale, except in the lower part of the titre range. Plotted on this scale, the take rates of nearly all vaccine specimens of the required strength (> 108 PFU/ml) were lower than anticipated by linear extrapolation from low titres. Differences between batches were noted. These findings relate to pulp processing without purification. Fluorocarbon extraction of the calf skin harvest resulted in a 4-fold increase of vaccine volume with commensurate virus dilution; it also gave clearly higher take rates than parallel nonpurified vaccine specimens, whether at original strength or at 4-fold dilution. Full text Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.1M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References . 185 186 187 188 189 190 191 192 193 194
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