The news that MMR uptake rates have improved, with 90% of two-year-olds in the UK having their first dose, is encouraging.
But, before we start celebrating, the other news is that more cases of measles have been confirmed in the first five months of this year than in the whole of 2010.
While it might seem contradictory that we’re seeing lots of measles just as the highest MMR vaccine rates for 13 years are reached, it’s not surprising. Most of the cases are among people aged 10-17 years; the vast majority of them never had the MMR vaccine.
These are the children and young people whose parents were to afraid to give them MMR vaccine when they were young because they were worried that it might cause autism.
The paper that triggered these concerns by Andrew Wakefield, John Walker-Smith, and 11 others from the Royal Free medical school in London and published in the Lancet in 1998, has been discredited but, at the time, was widely interpreted as showing that MMR vaccine caused autism and bowel disease. The intense media coverage it received worried many parents. Some remain afraid of this vaccine.
Despite the rise in vaccine uptake among young children, this is still not high enough to prevent outbreaks of measles. As it is one of the most infectious diseases, high rates of immunity (95%) across the board are needed to stop it from spreading, but in some areas uptake is much lower than 90%, notably London.
When measles is introduced into places where susceptible people group together –such as in universities and schools – the infection spreads rapidly. This is happening in England and in other European countries. In 2010, France, Bulgaria, Italy, Germany, Ireland and Spain experienced more than 30,000 cases.
These outbreaks have reminded us how nasty measles is. At best, it makes people feel unwell, with a rash, high temperature, conjunctivitis and a cough, but complications include convulsions, pneumonia and encephalitis. In the European outbreaks, nearly 22,000 people were admitted to hospital and 21 people died.
We have the means to stop further cases by offering the vaccine to people who may have missed out earlier, as well as to infants coming for their routine 12-month dose and their second dose at three years, four months. There is no upper age limit for having the MMR vaccine and, in people aged over 18 months, the second dose can be given as soon as four weeks after the first.
The combination of the highly infectious nature of measles and the fact that one dose of MMR does not protect 1 in 10 people against measles, makes the second dose extremely important.
Identifying and offering vaccine to susceptible people requires extra effort on our part, but it is effort that is well-placed and, if successful, we could actually consign this nasty infection to the history books.
Helen Bedford is senior lecturer in children’s health, Centre for Paediatric Epidemiology and Biostatistics, UCL Institute of Child Health, London