Answer :
VIRUSES ARE MUCH SMALLER THAN THE BACTERIA AS IT IS NOTHING BUT ONLY RNA IT AFFECTS OUR CELL DNA. THE VIRUS DON'T HAVE ITS OWN BODY IT USES THE HOST'S BODY. SO IT VERY DIFFICULT TO KILL THE VIRUSES THAN BACTERIA
Answer:
Viruses have few biochemical mechanisms of their own. They enter our cells and use our machinery for their life process. This means that there are many virus specific targets to aim . But bacteria have their own specific metabolic pathways that can be easily blocked at some stage .Therefore making of antiviral medicine is harder than making anti-bacterial medicine.