Changes

Passive immunity is protection against [[disease]] through [[antibodies]] produced by another human being or animal. Passive immunity is effective, but protection is generally limited and diminishes over time (usually a few weeks or months).  

Passive immunity is protection against [[disease]] through [[antibodies]] produced by another human being or animal. Passive immunity is effective, but protection is generally limited and diminishes over time (usually a few weeks or months).  

For example, maternal antibodies are passed to the infant prior to birth. These antibodies temporarily protect the baby for the first 4-6 months of life.

For example, maternal antibodies are passed to the infant prior to birth. These antibodies temporarily protect the baby for the first 4-6 months of life.<ref>http://www.cdc.gov/vaccines/about/terms/glossary.htm#p</ref>