A vaccine works by generating an immune response in the body against some kind of pathogen—a virus or bacteria or some other agent that causes disease. Normally when a pathogen invades the body ...

Bloodborne pathogens are microorganisms such as viruses or bacteria ... It too is transmitted by blood and body fluids but is harder to transmit. On the other hand once people become infected around ...

Then, if cowpox or the similar smallpox ever enters the body, the immune system will quickly get rid of the invaders. The smallpox vaccine is complete. Select another pathogen. Congratulations.

It is part of the body’s non-specific first line of defence. Stomach acid is hydrochloric acid and, while it does us no harm, it is strong enough to kill any pathogens that have been caught in ...