21.   Both drugs are based on interferon, one of the natural proteins produced by the immune system to ward off virus infections.

22.   But both Campbell and Troutman emphasized Friday that the first line of defense against West Nile virus infection is preventive behavior by individuals.

23.   Drugs like ribavirin, which is effective against Lassa fever, another hemorrhagic viral illness, are not effective against hanta virus infection, Schmaljohn said.

24.   Fauci added that, to him, the discovery was more important for understanding how the AIDS virus infection becomes chronic.

25.   He was suffering from a severe virus infection, said his daughter Martha Ferguson.

26.   Health Department officials stressed that Hanta virus infection in humans is extremely rare and may well have gone unnoticed in the past.

27.   His trainer, Roger Attfield, reported that the colt had come down with a virus infection but was strong now.

28.   Ho and Shaw independently realized that they could use powerful new drugs to create a snapshot of the dynamics of an AIDS virus infection in progress.

29.   It is also possible that a low-grade virus infection may still be going on, that is enough to cause the discomfort, but no blisters.

30.   Last year he was hospitalized and spent several months recuperating from a virus infection.