Guinea-pigs immunised with Zinsser-Castaneda vaccine prepared from a mexican murine tuphus strain have been shown to be immune to subsequent infection with South African epidemic typhus. It has been shown that one injection of Zinsser-Castaneda vaccine, which has been precipitated by alum, produces a high degree of immunity. This high degree of immunity is not appreciably increased by two injections at a nine-day interval of smaller doses of the alum-precipitated vaccine.
*Received October 2, 1940. This item could possibly be incomplete in the online version of the journal. Sabinet Gateway encourages anyone with access to the full version of the article to contact the African Journal Archive (www.ajarchive.org) to enable us to restore the article to its original state.