WK 10- IMMUNISATION Flashcards
How do vaccinations work
Stimulate the immune system to create antibodies/memory cells in the absence of disease symptoms
What is herd immunity
Is the resistance of a group to invasion and spread of an infectious agent, based on the immunity of a high proportion of individual members of the herd
-stops the infiltration and spread of disease, protecting those who are not immunised
What is the process of vaccine development
- Have to separate disease causing effects from the immune generating effects in an organism
- Give it to susceptible individuals in order to produce an immune response
- End up with non susceptible, immune individuals and eventually herd immunity
What are the 5 different types of vaccines
Live, Killed/inactivated, Acellular, Toxoid, Adjuvants/Conjugates
What are live vaccines
Use the attenuated (weakened by attacking the virulence factors) form of the virus. The measles, mumps, and rubella (MMR) vaccine and the varicella (chickenpox) vaccine are examples.
What are killed/inactivated vaccines
A vaccine consisting of virus particles, bacteria, or other pathogens that have been grown in culture and then killed using a method such as heat, radiation or formaldehyde–> eg flu vaccine
What are acellular vaccines
Contain generally part of organism involved in immune response that cannot replicate→ capsule, flagella, part of protein wall (no RNA/no DNA), aka subunit vaccines
What are toxoid vaccines
Contain a toxin or chemical made by the bacteria or virus. They make you immune to the harmful effects of the infection, instead of to the infective agent/pathogen itself. Examples are the diphtheria and tetanus vaccines.
How can someone who has been immunised have diptheria but not be incredibly ill
In those who are vaccinated with a toxoid vaccine against diptheria, the pathogen can be present but does not produce the toxin that causes disease, but the organism can still grow→ harmful to people who aren’t vaccinated as they will be affected by the pathogen and the toxins released
What is an adjuvant/conjugate vaccine
Agents (including other vaccines) that increase the immune response (take something the body is good at making an immune response to)
What is the transmission of measles and what is the infectious period and incubation period
- Airborne
- Infectious from prodrome (which is generally a rash) to 4 days after onset of prodrome
- Incubation period: around 10 days to onset of fever, and 14 days to onset of rash
What is the incubation period
Time elapsed between exposure to a pathogenic organism, a chemical, or radiation, and when symptoms and signs are first apparent.
What is the period of communicability
refers to the time during which an infectious agent can be transmitted directly or indirectly from an infected person to another person
What are the symptoms with measles
Prodrome (an early symptom indicating the onset of a disease or illness)- fever, malaise
-cough, coryza (Irritation and swelling of the mucous membrane in the nose), conjunctivitis, maculopopular rash starting on face and spreading to rest of body, koplik spots
What are the complications of measles
otitis media (9%), pneumonia (6%), diarrhoea (8%), acute encephalitis (0.1%)→ mortality 10-15%, up to 40% of survivors with permanent neurological sequelae, SSPE- rarest- (Subacute sclerosing panencephalitis- brain inflammation)→ 7 years post infection, universally fatal
What is the vaccine schedule with measles vaccinations
Given in MMR/V vaccine
- 1st dose at age 12 mos
- 2nd dose at age 18 mos
- Catch up 2nd dose to age 4 (now changed to second dosage being given before age 4)
What is the transmission of rubella
Airborne droplet spread, contact with mucus membranes
-Infants with CRS shed virus in pharyngeal secretions and urine
What is the
- incubation period and
- period of communicability of rubella
Incubation; get symptoms after 14-21 days
Contagious: 1 week before and 4 days after appearance of rash
What is congenital rubella syndrome
90% of babies in womb when the mother gets rubella will develop CRS- can result in hearing loss
What are the symptoms of rubella
Generally mild, self limiting (which means that people generally consider their symptoms low and therefore move around-spreading disease), Low grade fever, Headache, Malaise, Coryza, conjunctivitis, Lymphadenopathy, Arthralgia, Rash
What are the complications of rubella
- CRS (congenital rubella syndrome)
- Post viral encephalitis
What is the schedule for rubella vaccine
Not given in pregnancy (as it is a live vaccine) but given seronegative women of child bearing age
- 1st dose at age 12 mos
- 2nd dose at age 18 mos
- Catch up 2nd dose to age 4
What is the transmission method of pertussis (whooping cough)
Airborne droplet spread, highly infectious
What is the incubation/period of communicability of pertussis
incubation= symptoms after 7-20 -POC= 21 days after onset of cough
What are the symptoms of pertussis
Acute cough lasting >/= 14 days with at least one post-tussive comiting, apnoea or whoop
- Cough persists for up to 3 months-sleep disturbance/ rib fracture
- Causes: pneumonia, seizures and hypoxic encephalopathy
Who are most at risk for pertussis (whooping cough)
infants who have not had 2 doses of vaccine (maternal antibody does not provide reliable protection), adults and adolescents with waning immunity- the disease is far more severe in infants
What are the vaccinations available for pertussis
Vacs are put in combination with inactivated polio, hep B and Hib
-Given as DTPa (children)/ dTpa
What is the schedule for the DTPa vac
-Schedule: 2, 4 and 6 months; booster at 4 years (DTPa) and 12-17 years (dTpa)
What are the contraindications for DTPa vax
- Immunocompromised (live vaccines)
- Pregnant or may be pregnant (live vaccines)
- Fever >38.5C
- Recent (<4weeks) live vaccine
- Recent (<7mos) blood or blood products eg. immune globulin (<11 mos)
- GBS (influenza)
What extra vaccinations are available for ATSI population
ATSI children are given all the same vaccines on the schedule- plus Hep A, extre pneumococcal, influenza, japanese encephalitis
What extra vaccinations are available for medically at risk patients
Receive all the same vacs plus extra pneumococcal and influenza
What is the no jab no play/pay scheme
Parents who do not immunise their children will not receive benefits from the government in terms of childcare- those children are also excluded from childcare centres if an outbreak occurs to prevent harm to others
What are some occupations that require different vaccinations on top of the regular
Healthcare workers: HepB, MMRV, DTPa, Hep A, BCG
Abattoir workers, farmers: Q fever
Vets: influenza, Q fever, rabies
What is bat lyssavirus
Closely related to rabies-exposures to bites/scratches can cause rabies like symptoms and potentially lead to death
What prophylaxis is required for non-immunised patients who have been bitten
Require immediate rabies dosage delivered IM on days 0, 3, 7, 14 and Ig
What prophylaxis is required for immunised patients who have been bitten
2 doses of rabies vaccine delivered IM on days 0 and 3
What are the 2 vaccines for polio
OPV and IPV
What is the OPV vaccine- is it still in use in australia
Live attenuated vaccine that is more effective, but has small risk of causing disease in immunosuppresed people AND the risk of getting complications from the OPV vaccine was higher than the risk of getting polio, so no longer used in australia but is used in countries that are still considered polio sources (Afghanistan and Pakistan)
What vaccine is used to prevent polio in aus
IPV- changed from OPV to IPV to reduce risk (is safer) but is also slightly less effective
What is the zoster vaccination and who receives it
Booster vaccination to varicella- given to over 70’s to prevent shingles (not the same as varicella vaccination)–> should not be given to immunocompromised people
What vaccination is given at birth
Hepatitis B
What vaccinations are given at 2 months
Diphtheria, tetanus, pertussis, hepatitis B,
poliomyelitis, Haemophilus, influenzae type b (Hib), pneumoccocal, rotavirus
What vaccinations are given to 4 months old
Diphtheria, tetanus, pertussis, hepatitis B,
poliomyelitis, Haemophilus, influenzae type b (Hib), pneumoccocal, rotavirus
What vaccinations are given to 6 months
Diphtheria, tetanus, pertussis, hepatitis B,
poliomyelitis, Haemophilus, influenzae type b (Hib), pneumoccocal, rotavirus
What vaccinations are given to 12 month olds
MMR, Meningococcal, Hib
What vaccinations are given to 18 month olds
MMRV, Diphtheria, tetanus, pertussis
What vaccinations are given to 4 year olds
Diphtheria , tetanus , whooping cough (pertussis) , polio (poliomyelitis)
What is the latest age that rotavirus vaccination is given
6 months
What is the cold chain
-The ‘cold chain’ is the system of transporting and storing vaccines within the
Safe temperature range of +2°C to +8°C.
What are the stages of cold chain
The cold chain begins from the time the vaccine is manufactured, continues through to the state or territory vaccine distribution centres and ends when the vaccine is administered
What is the temperature to be aimed for? What is the acceptable range?
-Safe temperature range of +2°C to +8°C.
Which environmental exposures are capable of damaging vaccines?
- heat→ anything that raises temperatures above 2-8 degrees
- if the vaccine becomes frozen
- if the vaccine is exposed to direct sunlight or UV light, including fluorescent light
