This paper is the record of an investigation of the causes of failure in the cow-pox vaccination of persons entering the University of California with no visible evidence of a previous vaccinia.
VACCINATION PREVIOUS TO THE BEGINNING OF THE INVESTIGATION
All intrants not showing a vaccination scar were vaccinated. Failure to "take" resulted in a repetition of the vaccination twice during the first term, and once every succeeding term during residence at the university.
The arm was scrubbed with soap and sterile water, rinsed with alcohol and dried with cotton. An area about 5 mm. square was scarified with a dry vaccine point, which was then wiped on the serum exuding from the scarified spot. A gauze square was then applied to the wound and was secured by four strips of adhesive tape. Verbal instructions were given the person regarding the protection of the arm, and return for