申論題

6. The smallpox virus circulated and plagued the human population for many centuries until 1979, thanks to the advent of effective vaccines developed by Dr. Edward Jenner using the skin material of a milkmaid infected by the cowpox virus. Please describe the principle of vaccination against viral infection. Please describe the potential mechanisms of how the cowpox virus vaccine protects humans from smallpox virus infection. (4 points) If you were to develop a new version of the smallpox virus vaccine using current technology, which approach would you take and why?