Vaccines: Bacterial and Viral Flashcards
UK immunisation schedule
State vaccines used in the UK immunisation schedule?
- Neisseria meningitidis group C, B
- A, Y, W Haemophilus influenzae type b,
- Streptococcus pneumonia
- Influenza virus
- Tuberculosis (BCG)
- Tetanus
- Diphtheria
- Pertussis Measles
- Mumps
- Rubella Polio
- Hepatitis B
- HPV
- VZV
State the schedule for babies under 1 years old + explain them?
- 6 in 1 -> Diptheria, tetanus, pertussis, polio (inactivated vaccine), haemophilus influenzae b, hepatitis B
- Rotavirus (diarrhoea + sickness): oral live vaccine
- PCV -> conjugated vaccine: given x2 for boosting
- D/T/P vaccines are toxoids ->Hib conjugated, HeB recombinant sub-unit, polio inactivated (via reversion to virulence) -> none are live -> 3x boosting
State the schedule for children 1-15 vs old + explain them?
- MMR -> live attenudated -> X2 due to decreased uptake first dose
- 4 in 1: tetanus, diptheria, whooping cough, polio
- 3 in 1: tetanus, diptheria, polio
State the schedule for adults 65-70
- 65 years: Pneumococcal (PPV) vaccine
- 65 years (and every year after): Flu vaccine
- 70 years: Shingles vaccine
Explain shingles component?
- Shingles
- Via chickenpox virus -> skin rash + enduring nerve pain (post-herpetic neuralgia) (- if caught as kid, remains dormant in spinal nerve cells for decade + reactivated for shingles)
- Decreased immune system function
- Two vaccines -> zostavax (live) + shingrex (recombinant subunit)
State the schedule for pregnant women?
- During flu season: Flu vaccine
- From 16 weeks pregnant: Whooping cough (pertussis) vaccine
Vaccines- Neisseria meningitidis
Describe Neisseria meningitidis + state its vaccines?
- Neisseria meningitidis: G-ve
- Meningococcal disease -> Meningitis + Sepsis
- Characterised via Polysaccharide coat
- 6 serogroups (A, B,C, W-135, X,Y)
- Men C + Men B vaccine
Why was Men C dropped from vaccination schedule in 2013, but then reintroduced in 2015?
2013: the Men dose at 4 months was dropped from the schedule. By this time levels of MenC disease had fallen very significantly
2015: the single MenC dose for teenagers and new university students was replaced by a combination vaccine, the MenACWY vaccine, which offered protection against four strains of meningococcal disease including type C. It was introduced because of a significant increase in cases of MenW disease in the UK.
Describe the current schedule of Men C vaccines?
HiB/MenC combined vaccine given at 1 year: tradename Menitorix
- MenC is a conjugated bacterial polysaccharide conjugated to tetanus toxoid
- Men ACWY - 14 years -> names: Menveo (polvsaccharides from A,C.W-135, Y conjugated to diptheria toxoid) OR Nimenrix (conjugated to tetanus toxoid)
Describe the components of men vaccine?
Bexsero: 3 major proteins on surface of meningococcal bacteria + outer membrane of 1 men B strain
- Produced in E.coli cells via recombinant DNA tech + adsorbed on aluminium hydroxide
Describe H.influenzae + its vaccine?
- Gram negative
- Causes paediatric disease
- Hib Vaccine: type b capsule polysaccharide linked to conjugate -> diphtheria, tetanus toxoids OR meningococcal outer membrane proteins
Bacterial toxin diseases- Diptheria
Describe diptheria toxin with its effects?
- Caused by Corynebacterium diphtheria
- DT inhibits protein synthesis in eukaryotes -> Pharynx, larynx, nose - non-invasive multiplication -> produced locally but acts at a distance gelatinous exudate -> absorbed by lymphatics – systemic effects damages heart, kidney, nerves, adrenals -> kills epithelial cells and polymorphs + ulcer - necrotic exudate - Pseudomembrane -› local inflammation -> Bull Neck
- Respiratory obstruction can be life threatening
Describe the vaccine for the diptheria toxin?
- Treated to make the toxoid immunogenic
- Combined with alum (adjuvant)
- Given as combined vaccine DaP or dTaP (D = increased amount of toxoid)
Describe features of Clostridium tetani and how it exerts its effect?
- Features: Gram +ve rods, terminal drumstick spores anaerobe, Soil dweller
- neurotoxin -> inhibits NM release (GABA, glycin) from inhibitory interneurons -> interact with motor neurones -> violent spastic paralysis
Describe tetanus vaccine for clostridium tetani?
Tetanus toxin is treated with formaldehyde -> converted to toxoid -> Decreased toxicity but not immunogenicity -> Combined with aluminium salt adjuvants
Whooping cough: Pertussis (bordetella pertussis)
Describe clinical effects of the whooping cough: pertussis?
- Severe cough lasting weeks often with a ‘whoop’ noise
- Bacterium adheres to ciliated epithelial cells in upper respiratory tract + multiplies.
- In infants may descend to lungs (can cause death -> Secretes pertussis toxin which is a virulence factor in pathogenesis
- Causes many of systemic symptoms including profound leukocytosis (1 WBC) often observed in children
Describe the vaccine for whooping cough?
- Acellular vaccine
- Contains: Pertussis toxoid, Filamentous haemagglutinin (1 cell adhesion), Pertactin (1 cell adhesion)
- Blocks adhesion + neutralises toxin
Who recieves influenza vaccine?
- Pregnant
- Elderly
- Immunosuppressed
- Work in close contact with poultry
Describe the influenza virus?
- 3 types: A,B.C
- Glycoproteins (H + N) play important role
- Antigenic drift + shift
- Epidemic or even pandemics
Describe the composition of the flu vaccine?
- Quadrivalent (2 subtypes of IA + IB)
- Vaccines grown either in embryonated hens’ eggs or in cell culture -> inactivated -> One live attenuated vaccine is Fluenz Tetra® (nasal spray) -> Attenuated so that it can only replicate in the cold - only in nasal passages
State the factors affecting influenza vaccine effectiveness?
- Variable by year/age group
- Antigenic drift + shift
- Mismatch between vaccine + circulating disease can decrease effectiveness of vaccine
- Manufacturing issues can occur
- Tight schedule between WHO recommendations for vaccine and the beginning of flu season
Describe features of Streptococcus pneumonia
- Causes pneumococcal disease
- Invasive disease: where the bacterium can be isolated from blood or from another location which is normally sterile
State and Describe the vaccines for Streptococcus pneumonia
- Pneumococcal Polysaccharide Vaccine PPV23 -> PS from 23 serotypes for at risk adults + >2 yrs old -> Under 2 can’t make long lasting immune response so need conjugated vaccine
- Pneumococcal Conjugate Vaccine: PCV 13 (Prevenar 13) - PS from 13 most common capsule types -> Conjugated to diptheria toxoid
Describe HPV?
- Human papillomavirus: Over 40 types
- Causes genital warts
- High risk types (serotypes 16,18)
- Lead to cervical cancer (• HPV16: 50% • HPV18: 20%) + Low risk types (6,11) - warts
