Republican US presidential candidate Michele Bachmann has been slammed by the medical community over her remarks about the HPV vaccination.
Two bioethics professors have challenged Bachmann, who suggested this week that an STD vaccine could cause "mental retardation", to prove her point, the New York Daily News reports.
The educators have offered the Minnesota congresswoman over 10,000 dollars to produce any evidence for her implication that a vaccination against human papillomavirus could lead to mental retardation.
The medical community challenged her after she relayed a story about a mother whose daughter received the vaccine.
"She told me that her little daughter took that vaccine, that injection, and she suffered from mental retardation thereafter. It can have very dangerous side effects. Today, this is the very real concern, and people have to draw their own conclusions," Bachmann added.
Bachmann made the statement in response to her GOP rival, Texas Gov. Rick Perry, who came under scrutiny for signing a 2007 executive order requiring sixth-grade girls in Texas to be vaccinated against HPV, an STD that can lead to cervical cancer.