If you used a full active virus, that defeats the point of a vaccine. You will trigger your immune response, but since you would just be injecting the virus, it will make you sick, and your body will be less effective at fighting the pathogens.
Viruses in vaccines are weakened, so they essentially will not "fight" back. They most importantly just contains the antigen markers so the body can trigger the immune response, quickly eradicate the pathogen, and build up the memory cells to that virus.
Injecting a virus that is not weak will just be the same thing as if you got the virus, you will likely get sick.
It reproduces cells to work for all systems
Answer: Eye drops are effective when it placed into the eyes with care and proper instructions.
Eye drops should be placed in the lower conjunctival sac that starts at the inner side of the eye not the outer side called as canthus.
If the eye drops are dropeed on the cornea of the eyes and this causes discomfort and hence should be avoided.
It should not be placed on the opening of the lacrimal ducts otherwise it will avoid the systemic absorption.
