A transposon insertion mutant of Listeria monocytogenes was shown to be deficient in prephenate dehydratase, an enzyme acting late in the pathway for biosynthesis of phenylalanine. This mutant had reduced virulence in mice. The mutant and parent strains persisted to the same extent in the tissues of infected mice and elicited similar degrees of splenomegaly. Mice vaccinated with the mutant were...

Antimalarial treatments during primary Plasmodium berghei NK65 infection in BALB/c mice influenced the acquisition of protective immunity against reinfection. Among subcurative treatments, lower doses better enable mice to acquire protective immunity than do higher doses. Eradication of parasites from the start of infection did not promote protective immunity.

BACKGROUND The low uptake of tetanus vaccine and its resultant high burden of tetanus in Nigeria suggest the need to improve routine and booster vaccination in children and adolescents. However, epidemiological evidence for vaccination in the adolescent age group needed for effective strategy and policy formulation is lacking. This study was carried out to determine the prevalence of protective...