July 24, 2020 12:30 PM EDT

(LONDON) — U.K. Prime Minister Boris Johnson has dismissed campaigners seeking to oppose vaccinations, describing so-called anti-vaxxers as “nuts.’’

Johnson asked staff at a London medical center what they thought of anti-vaxxers while adding, “There’s all these anti-vaxxers now. They are nuts, they are nuts.”

Johnson was touring the east London center to promote a campaign for flu vaccinations ahead of winter.

The anti-vaccination movement was fueled by a now-discredited article in the medical journal Lancet by Andrew Wakefield, which alleged the measles, mumps and rubella vaccine was linked to autism. The article was later retracted and Wakefield lost his medical license.

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