Experimental Rubella Studies<subtitle>I. Clinical and Laboratory Features of Infection Caused by the Brown Strain Rubella Virus</subtitle><subtitle>II. Artificial Challenge Studies of Adult Rubella Vaccinees</subtitle>

THERE ARE currently several candidate live, attenuated rubella virus vaccines being evaluated in human populations.¹,²The vaccines appear to be similar in their effects, although little information has been obtained on the ability of the vaccines to produce extended protection against natural rubella challenge. Only when vaccinees are exposed to repeated rubella outbreaks during the coming years can protection be properly evaluated. The recent report of Detels et al³indicated that rubella vaccines were protective, but in this investigation, vaccination and exposure to natural illness were almost simultaneous. The Clinical Virology Section (CVS) conducted a series of artificial rubella challenge studies to determine the protective effect of rubella vaccines. The initial study characterized the clinical and laboratory features produced by the administration of a low tissue culture passage rubella virus strain, the Brown strain. The Brown strain virus proved to be a suitable challenge virus. In the