I was reading recently about an outbreak of measles at Disneyland California, which has affected 70 people.
Because measles is highly contagious, people who have not had the MMR vaccine are now being advised to avoid the Disney parks in California. In 2000 the USA declared it had eradicated measles.
There was a period of time when the MMR vaccine was thought to be linked with autism and many parents chose to not have their children vaccinated as a result. In the UK at the moment we rarely see outbreaks of measles and rubella, however we do see outbreaks of mumps– often among students. One large outbreak in 2005 occurred in the group where many had not been immunised.
Immunisation protects us by causing our bodies to develop an immune response with the production of antibodies. This means that if we are faced with a real infection our bodies are primed to deal with it and we do not develop the illness.
Some people are not able to have vaccines – for example if they have had a severe allergy, or young babies who have not yet been immunised. These people depend on what we call “herd immunity”. If a large enough percentage of the population are immune (around 90-95 per cent) then this effectively protects the non-immune as the disease effectively is wiped out.
In Disney, it appears that a visitor brought measles to the USA and, because many in that area have decided not to be vaccinated, they have been susceptible and caught the infection. As doctors we hear stories of patients who have decided not to get their children immunised, or maybe just not had time or forgotten, and then occasionally a disaster happens. A child dies of a type of meningitis that could have been prevented, or a student develops mumps with complications and has reduced fertility.
In 1940 there were 61,000 cases of diptheria reported but none in 2005, all down to vaccination. The introduction of the meningitis C vaccine has reduced cases of this type of meningitis by 90 per cent We are privileged to live at a time when we rarely see these illnesses and infections, but let’s not forget to be proactive and get vaccinated.
I imagine some Disney visitors wish they had.