Australian Vaccination Schedule Flashcards
What is the Measles-Mumps-Rubella (MMR) vaccine?
- A mixture of live attenuated viruses administered via subcutaneous injection
Measles and mumps virus are produced in what cells?
Chick embryo cells
Rubella viruses are produced in what cells?
Human lung fibroblast cell line
What are the complications of measles?
Pneumonia
Inflammation of the middle ear
Acute post-infectious encephalitis
Subacute sclerosing panencephalitis (SSPE)
What is acute post-infectious encephalitis?
Measles virus-induced autoimmune disease that targets and destroys basic myelin proteins
What is subacute sclerosing panencephalitis (SSPE)?
A rare, chronic progressive encephalitis
Characterised by:
- History primary measles infection before the age of 2
- Followed by 6-15 asymptomatic years
- Then gradual, progressive psychoneurological deterioration
Describe the measles situation in Australia up until 2013.
Initially had high fatality rates
Better healthcare and nutrition, and vaccination dramatically reduced fatality rates
Receiving two doses of the vaccine was considered more effective in reducing fatality rates
However, had sporadic increases in case numbers due to areas that are anti-vaccination
When should you get the MMR vaccine?
Two doses of the MMR vaccine must be given to children aged 18 months and 5 years of age.
What is the vaccination schedule for chickenpox?
Children born on or after 1 May 2004 must receive the attenuated chickenpox virus when they turn 18 months old
What are the common symptoms and life-threatening complications of influenza?
Symptoms: Fever, sore throat, cough Severe headache Myalgia (muscle pain) Malaise (weakness and fatigue)
Complications:
Pneumonia
Hospitalisation
What are the consequences of influenza virus-induced damage?
Virus replicates in the lung epithelial cells
It destroys the cells, as well as the cilia, and leads to a cytokine storm and severe cell damage (which is how you get pneumonia)
What is genetic drift? How do influenza viruses escape immune response by genetic drift?
Genetic drift is caused by accumulation of mutations (mostly point mutations; to some extent, deletions and insertions)
An antibody is normally bound to haemoglutinin. Mutations in the haemoglutinin occur, leading to changes in its structure. As a result, the antibody can no longer bind to the haemoglutinin, now incapable of protecting the body against cell infection. This is how you get seasonal flu.
What is genetic shift? How do influenza viruses escape the immune response by genetic shift?
Genetic shift is caused by reassortment, which occurs in cells infected with different influenza viruses
For example, haemoglutinin and neuraminidase infect one cell. The strains mix and produce a new strain which the body has no protection against. Immune response is evaded.
Why are new influenza vaccines needed every year?
Because the strains of influenza viruses change yearly
Describe how influenza vaccines are produced.
- Study the epidemiology of the occurring strains
- Characterise and sequence the strains
- Select which strain/s will be used for the vaccine
- Manipulate the growth to make sufficient vaccines and get high yield growth in chicken eggs
