Wakefield, 60, and Macpherson, 54, were visiting an organic farmers’ market in Miami. Both now live in the US and they have been spotted together several times in recent months.
Wakefield was banned from practising medicine in the UK in 2010 but continues to campaign in the US against vaccines. He attended one of President Trump’s inauguration balls 18 months ago. Mr Trump has voiced support for the so-called anti-vaxxer movement.
Wakefield sparked worldwide alarm in 1998 when, as a consultant gastroenterologist at the Royal Free Hospital in Hampstead, he published a research paper in The Lancet that linked the measles, mumps and rubella vaccine with autism and bowel disease.
The study was based on symptoms he claimed to have seen in 12 children. It was found to be false and was eventually withdrawn by the journal.
Doctors have blamed the scandal’s legacy for measles outbreaks, most recently across Europe, which have wiped out progress in eliminating the disease.
Macpherson, nicknamed The Body, divorced billionaire property developer Jeffrey Soffer last year.
She has two children, Flynn, 19, and Aurelius, 14, from her previous relationship with financier Arpad Busson. Wakefield separated from wife Carmel last year.
Macpherson’s agent told the Evening Standard today she was aware of press reports of a relationship with Wakefield but declined to comment.
Children born between 1998 and 2002, at the height of the Wakefield scandal, are most likely to have missed either or both doses of the MMR vaccine, which is given in two doses, just before a baby’s first birthday and at three years four months.
Take-up has been low in countries such as Romania, France, Greece, and Italy, with at least 49 measles deaths reported in the EU since 2016.
According to Public Health England, there were 757 laboratory-confirmed cases of measles between January 1 and July 6 this year.
This is almost three times the 274 recorded for the whole of last year. Of this year’s cases, 268 have been reported in London.
PHE said it was not too late to get a catch-up vaccine and advised people to check with their GP.
Dr Mary Ramsay, head of immunisation at PHE, said: “The measles outbreaks we are currently seeing in England are linked to ongoing large outbreaks in Europe.
“The majority of cases we are seeing are in teenagers and young adults who missed out on their MMR vaccine when they were children.”
Professor Helen Stokes-Lampard, chairman of the Royal College of GPs, has said the rising measles figures were “so disheartening when we consider how close we came to completely eradicating this unpleasant infectious illness”.