Most people understand the basic idea of a traditional live-attenuated or killed vaccine–the vaccine gives the body’s immune system a sneak peek at the virus so that when a wild type attacks, the body’s immune system has been trained to fight. It’s less well understood, however, that the newer, designed vaccines, can be better than traditional vaccines and better even than immunity from exposure to the wild virus because a vaccine can now be designed to target the immune system on the weakest part of the virus:
NYTimes: One beauty of vaccines — and one of their great advantages over our body’s natural reaction to infections — is that their antigens can be designed to focus the immune response on a virus’s Achilles heel (whatever that may be).
…The immune response generated against a virus during natural infection is, to some degree, at the mercy of the virus itself. Not so with vaccines.
Since many viruses evade the innate immune system, natural infections sometimes do not result in robust or long-lasting immunity. The human papillomavirus is one of them, which is why it can cause chronic infections. The papillomavirus vaccine triggers a far better antibody response to its viral antigen than does a natural HPV infection: It is almost 100 percent effective in preventing HPV infection and disease.