antigenic variation and vaccinations

• Vaccines are a dead or weakened version of a pathogen that allow individuals to become immune to disease without experiencing it.
• The differences between active and passive immunity is that active involves memory cells, while passive does not.
• Herd immunity is the process of vaccinating the majority of a population so those who are not vaccinated are less likely to catch the disease.
• Ring immunity is a selected number of people vaccinated to be protected from an infectious individual.
• Ethical issues of vaccines include the use of animals for testing, risk of side effects vs risk of long term harm, vaccine trials - risk to participants, and compulsory vaccination.
• Antigenic variation is when the attachment proteins change shape, they either shift or shift, meaning that the immune response has to occur again.
• A defective immune system may not detect a vaccine and not produce an immune response, which could be due to age or poor nutrition.
• Live oral vaccines have the potential to pass through the digestive system and into the water system, infecting others.
• Antigen concealment is when the pathogen lives inside body cells where antibodies cannot go, such as in malaria.
• Some pathogens weaken the immune system by living in B & T cells, like HIV.