A drug that boosts a woman’s immune system during pregnancy may help prevent her from passing along a common but dangerous virus to her unborn baby, Italian researchers report.The drug, called hyperimmune globulin, cut rates of mother-to-child transmission of cytomegalovirus (CMV) to just 3 percent of babies born to women infected with the virus.In contrast, 50 percent of infected mothers who did not receive the treatment passed on the potentially harmful pathogen to their newborn."Hyperimmune globulin was effective in treating and preventing mothers from transmitting the infection,” said study co-author Dr. Stuart Adler, a professor of pediatrics and chairman of infectious disease at the Medical College of Virginia Campus of Virginia Commonwealth University in Richmond. His team published their findings in the Sept. 29 issue of the New England Journal of Medicine.