The disgraced British former doctor who became the face of the anti-vaccine movement has claimed vaccines have made measles "a more dangerous disease", as he fundraises for a second film targeting the HPV vaccine.

Andrew Wakefield made a rare public appearance in Chicago on Sunday during which he claimed the country faced an imminent crisis because vaccinations have created a mutant strain of the virus.

"There are two elements to this problem," he told an audience at an autism conference. "One is that the measles vaccine is itself causing measles and the second is that the measles vaccine is not producing immunity that protects either against natural measles or the vaccine-induced measles."

Mr Wakefield co-authored a 1998 paper suggesting a possible link between the MMR vaccine and autism. Ten of the report's co-authors have since retracted the paper’s assertions after an investigation found that it relied on bogus data although Mr Wakefield repeatedly denied any wrongdoing and declined to retract the paper’s findings.

The inquiry uncovered financial and ethical conflicts of interest which led to him being struck off the British medical register in 2010. He later relocated to America, where he has continued to promote his views and become something of a cause célèbre among anti-vaccine groups in the country.