London is at risk of a measles outbreak, because at the height of the MMR scare - it had the lowest rate of MMR vaccination in the country.
The capital is singled out for a warning by health bosses, as they launch a so-called "catch up" programme - aimed at teenagers who haven't been inoculated.
Liz Wickham reports.
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Health bosses are warning that the capital is particularly at risk of a measles outbreak - as London has the lowest MMR vaccination rate in the country.
Latest figures show an increase in the number of cases in the first three months of this year.
The Government is launching a £20 million campaign to vaccinate a generation of children thought to be the cause of a measles outbreak.
This year is on course to be the worst year for measles outbreaks in two decades.
Already, in the first three months there have been 587 cases in England.
For more information visit the Get Vaccinated England Facebook page.