A***l
发帖数: 302 | 1 Since Edward Jenner developed the first vaccine to prevent smallpox
infections, vaccination has gradually become one of the most effective
medical interventions against many bacterial and viral diseases.
Traditionally the vaccines were live strains derived from virulent
cultures isolated from cases of natural infection. For example, attenuated
vaccines, killed vaccines and toxoid vaccines (detoxified toxins) have
been successfully applied to a variety of diseases including cholera,
plague, dysen |
|
