Immunology Flashcards
what are the two types of immunity?
- passive
- active
what is passive immunity and when does this occur naturally?
- the transfer of pre-formed antibodies to a susceptible individual giving temporary protection from infection
- occurs naturally - mother to baby via the placenta and breast milk
what are some examples of live attenuated (weakened) vaccines?
- Tuberculosis (BCG vaccine)
- MMR (measles, mumps, rubella)
- varicella-zoster (chicken pox)
- rotavirus
- yellow fever
- oral typhoid
- intra-nasal influenza
- oral polio (Sabin)
what are the advantages of using a live attenuated vaccine?
- immunogenic (resembles a natural infection)
- replicates in patient, excellent immune response
what are the disadvantages of using a live attenuated vaccine?
- not suitable for high risk groups (pregnant women, immunocompromised)
- can potentially develop the vaccine strain infection
- need mature adaptive immune system
what is inactivated whole cell immunity?
- pathogen is killed by chemical or physical processes and then inserted into patient
- cannot give the patient the infection as it’s dead, and therefore high risk groups can have it but immune response may not be great
Give an example of an inactivated whole cell vaccine.
- inactivated polio (Salk)
- hepatitis A
- rabies
what is inactivated toxin (toxoid) immunity and give an example of a vaccine
- toxins which are chemically treated to elimate toxicity whilst maintaining immunogenicity (eg. with formaldehyde)
- eg. Diphtheria, Tetanus
what is subunit immunity and give an example of a vaccine
- a bit of a virus or bacteria is inserted
- cannot infect patient as not whole pathogen
TWO TYPES: - recombinant proteins (eg. Hepatitis B, Papillomavirus)
- chemically purified (eg. Acellular pertussis, influenza)
what is polysaccharide immunity and give an example of a vaccine
- poorly immunogenic in young children so not used for children
- T-cell independent - no memory cells produced
- eg. some meningococcal, some pneumococcal, salmonella
what is conjugated polysaccharide immunity, what are some advantages over polysaccharide immunity, and give an example of a vaccine
- purified bacterial polysaccharide is joined to a protein
- T-cell dependent - memory cells produced
- more immunogenic than polysaccharides on their own and is used in children
- eg. Haemophilus influenzae, pneumococcal, meningococcal
what are adjuvants and what are the most commonly used?
- agents that stimulate the immune system
- aluminum phosphate and aluminum hydroxide are commonly used
- thought to work by keeping the antigen at the site of infection for longer. causing inflammation, and attracting immune cells to the site of infection
which two vaccines are people advised to get at age 65?
- pneumococcal polysaccharide vaccine
- annual influenza vaccine
which vaccine are people advised to get at age 70?
- varicella-zoster (shingles)
which two vaccines are pregnant women advised to have?
- influenza in any trimester
- pertussis (whooping cough) from 16 weeks gestation
give some examples of when post-exposure vaccines would be given.
- wounds at high risk of tetanus (specific immunoglobulin given)
- potential rabies exposure (course of vaccine + specific immunoglobulin given)
- unvaccinated contact with confirmed measles case (vaccine given)