Health bosses are warning the number of measles cases this year are expected to exceed the 139 recorded last year. New figures show cases have nearly doubled compared to the same period last year.
In January - April 2012, 52 people were diagnosed - and London is expected to exceed the 2012 whole-year total of 139 cases. A catch-up programme is now being run to increase MMR vaccination.
There have now been 103 confirmed cases of measles in London so far this year.
That's almost double to 52 cases of the disease which had been recorded by this point last year.
Experts now expect that the number of cases this year will exceed the total of 139 recorded last year.
The rise in case is being blamed on a fall in take up of the MMR vaccine, following a scare.
Health officials are urging parents to get their children vaccinated if they missed out on the MMR.
Public Health England is running a catch up program offering the jabs.
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.
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.
The capital has the lowest level of MMR vaccination take up in the country, and this puts it at particular risk of suffering a measles outbreak.
With the number of cases of the disease already rising, Public Health England are so concerned they're launching a catch-up vaccination programme.
They're particularly concerned about those aged 10-16 who may have missed out on the vaccine in the wake of the Andrew Wakefield scandal.
There have so far been 68 cases of measles in the capital so far this year- compared to just 137 for the whole of last year.
A global scare sparked by the "discredited and inaccurate" claims of a doctor 15 years ago over the MMR vaccine have caused huge worry to parents in South Wales following a measles epidemic in the region, Health Secretary Jeremy Hunt said.
Mr Hunt said Dr Andrew Wakefield's comments about the vaccination had "absolutely no scientific basis" as he urged parents of children who had not been given two doses to contact their local GP as soon as possible.
Mr Hunt told the Commons, "What Andrew Wakefield said had absolutely no scientific basis and has caused huge damage and huge worry to many thousands of parents".
"It is very important to reiterate that the scientific way to prevent measles, which can be a horrible, even fatal disease, is to make sure that you have had two doses of MMR", he continued.
"Parents of children who have not had those doses, parents of children of any age, should contact their GP if they have not had those two doses, particularly in the current circumstances".