Group B streptococci (GBS) are a major cause of neonatal sepsis and meningitis. Our studies in the rhesus monkey model suggest protection from GBS infection was not significantly associated with maternal antibody titer, prior immunization history or dose of GBS given. Maternal IgG may be insufficient to protect the unborn fetus should a GBS amniotic infection occur during partuition. Neuromuscular changes in rhesus monkeys of various ages: In our studies of polymyositis in rhesus monkeys we have found several neuromuscular changes not previously well described for this species. A study designed to observe possible neuromuscular changes associated with ageing of these animals was done. Preliminary findings show that changes of denervation start as early as age 10 and progress slowly there after. Simian Varicella (SV): A recent isolate of SV has been studied in several species of monkeys. Rhesus monkeys appear to be the best experimental host. SV virus produces a mild disseminated chicken pox-like infection. This model offers many advantages for study of human latency and diseases associated with Varicella Zoster.