Dear Student, Its easy to make antibacterial because bacteria have their own cell wall and also use their own machinery to replicate while Viruses don't have their own material and they use host machinery to replicate. So, There is no region which can be attacked to stop its multiplication. So, anti- virals are difficult to produce. Bacterial Disease is Pneumonia ( caused by Streptococcus Pneumoniae) while Viral Disease is AIDS(Acquired Immuno Deficiency Syndrome) caused by HIV (Human Immunodeficiency Virus). Regards