The recent epidemic of measles, largely in unvaccinated children, caused at least 140,000 deaths globally in 2018.’ In New Zealand (NZ) 2,185 cases had been reported during the 2019 outbreak.’ Measles is highly contagious?’ and of those infected 15% require hospitalisation and 1% develop encephalitis, of whom almost a half die or have permanent brain damage,
Summer, aged two years, has just returned home to NZ after an 18-month round-the-world journey on a yacht. Her parents left the yacht in Vancouver and flew home from there. Because of the travelling, Summer had not been vaccinated, although her mother planned to catch up on the required vaccinations after settling into their home. However, two weeks after returning home, Summer developed a cough, runny nose, inflamed eyes, sore throat, fever and a red, blotchy skin rash. After attending the family’s general practice, Summer was diagnosed with measles.
1. Describe the immune response to the measles infection that will enable Summer to fully recover and develop immunity against the measles virus .
2. The initial vaccine for measles, mumps, and rubella (MMR) is typically given to infants aged 12-15 months.’ 6 Explain the main reasons why this is not given within the first few months of life.
3. The reproduction number or R-nought (Ro) for measles is 12-18.7
a) Explain what this means in relation to measles?
b) Ro is also used to work out what proportion of the population need to be vaccinated to prevent the spread of measles. This is calculated by 1-(1/Ro).8 Calculate the proportion of people