Skin reactivity and antibody response following vaccination against smallpox

Abstract

Revaccination between 2 and 5 yr after the last vaccination induced higher complement fixation titers than revaccination 7-63 yr after the last vaccination. The highest CF titers were reached during the 3rd to the 5th wk after vaccination. 52 serum samples, taken 137 or more days after a successful vaccination, all showed CF titers lower than 1/2. In a group of successfully vaccinated persons with no postvaccinal complications, 65 out of 66 had a successful 'take' after 1 or 2 subsequent vaccinations. Sera of persons receiving primary vaccination showed significantly lower CF titers than sera of revaccinated persons. Cases of postvaccinal encephalitis showed greater antibody response than uncomplicated successfully vaccinated cases in both the primary vaccination and revaccination groups. The antibody response in revaccinated persons with postvaccinal encephalitis was greater than that in the group of successfully revaccinated cases without encephalitis. A group of 26 naturally hyporeactive persons completely failed to 'take' even after vaccination repeated between 3 and 10 times (average 5 times per person). The frequency of seropositives in this group, and the height of their CF titers, were significantly lower than in the group of successfully vaccinated persons. These findings support the view that untreated persons who repeatedly fail to 'take' with the vaccine must not be considered immune. In vaccinated persons treated with immunoglobulin (with or without simultaneous treatment with Marboran) antibody production was apparently diminished. Treatment of patients with Marboran significantly lowers the capacity of the vaccine to 'take'.