Kamala Harris refuses to say whether she would take the RNA vaccine if it becomes available in October or November.
President Trump has insisted a vaccine will be available by the end of the year, and potentially before the November 3 elections.
"It will be delivered before the end of the year, in my opinion, before the end of the year, but it really might even be delivered before the end of October," Trump said Thursday. "How do you like that? Wouldn't that be nice?"
But the Democratic vice presidential candidate said she doesn't trust Trump's word on the safety or efficacy of a vaccine that was rushed through three years' worth of clinical trials in a matter of months.
In an interview with CNN, Harris said, "I would not trust Donald Trump and it would have to be a credible source of information that talks about the efficacy and the reliability of whatever he's talking about. I will not take his word for it."
Alarm bells went off when the Centers of Disease Control and Prevention (CDC) sent letters to governors in every state requesting that states consider "waiving requirements" to allow vaccine distribution sites to be fully operational by November 1st.
Unlike normal vaccines, RNA vaccines are "encoded" with genetic "instructions" that tell your cells what to do.
Many Americans expressed concern that the CDC might be subjecting them to a potentially harmful vaccine.
Dr. Anthony Fauci, who sits on the White House Coronavirus Task Force, doesn't share their concern.
In an interview with Kaiser Health News earlier this week, Fauci said that Phase Three of the clinical trials could end earlier than expected, if the results prove "overwhelmingly positive."
Fauci told the publication that the Data and Safety Monitoring Board had a "moral obligation" to end the third phase of clinical trials early if the results were significant.
"I'm not concerned about political pressure," he added.
Fully one third of Americans say they would refuse the RNA vaccination even if it was deemed safe by the FDA and distributed to all 50 states before the election.