Dr Susanna Kent - Measles and vaccines - 4 August
Measles outbreak and immunisation
There is currently a measles outbreak which has begun in Christchurch. Over 90 people are confirmed as having measles.
What is measles?
Measles is a highly contagious infection. It is estimated that up to 13 people can be infected by one person with measles. The classic symptoms are high fever, cough, runny nose and conjunctivitis followed by a typical rash. It is spread by coughing and sneezing. You need to be away from others for at least 4 days after the rash appears.
Why is there a fuss about the outbreak?
It is highly infectious and measles can have complications. These include ear infections, pneumonia, diarrhoea and inflammation and swelling of the brain. (1 in 1000 get inflammation of the brain, 1-2 out of 1000 die out of all those with measles)
Measles also suppresses the immune system, making it more likely to get other infections.
How is it diagnosed?
It is a clinical diagnosis but is confirmed with a throat swab or blood test.
Can you prevent it?
The best way of prevention is by immunisation. This is routinely given as the MMR vaccine at age 15 months and then again at age 4 years. However, the second dose can be given a month after the first dose - and this is useful if your child has been in contact with someone with measles.
Approximately 90 to 95% of people who are immunised will be protected by 2 doses. Although some people may still get measles who have had the immunisation (this has happened in Christchurch), it is usually not as severe compared to those people who have not had vaccinations.
The measles vaccine was introduced in 1969. Most adults are thought to be immune to measles.
The MMR Vaccine
The measles vaccine is made up from a live measles virus that has been weakened (attenuated). So it is able to stimulate the body to create immunity, without getting the disease, or the complications of the disease.
Further information about the vaccine and disease can be found at the Immunisation Advisory Centre.