There are three main types of metadata: â¢ Descriptive metadata describes a resource for purposes such as discovery and identification.It can include elements such as title, abstract, author, and keywords. â¢ Structural metadata indicates how compound objects are put together, for example, how pages are ordered to form chapters.â¢ Administrative metadata provides information to help manage a resource, such as when and how it was created, file type and other technical information, and who can access it. Structural metadata indicates how compound objects are put together, for example, how pages are ordered to form chapters. â¢ Administrative metadata provides information to help manage a resource, such as when and how it was created, file type and other technical information, and who can access it.
Sabinâs live-virus, oral polio vaccine (administered in drops or on a sugar cube) soon replaced Salkâs killed-virus, injectable vaccine in many parts of the world.
The diphtheria, tetanus and pertussis vaccines are made this way. Another strategy to make a bacterial vaccine is to use part of the sugar coating (or polysaccharide) of the bacteria. Protection against infection by certain bacteria is based on immunity to this sugar coating (and not the whole bacteria).se part of the virus. Using this strategy, just one part of the virus is removed and used as a vaccine. The hepatitis B and the human papillomavirus (HPV) vaccines are made this way.