White House Chief of Staff Mark Meadows is doubling down on the possibility of a vaccine by the election day despite concern over its readiness. "I'm very optimistic that we will have something by the end of October," said Meadows Tuesday while talking to reporters on the White House driveway. "If you're looking at the end of October as Election Day, I would agree with the president that the progress to date has been extremely encouraging." This comes after Sen. Kamala Harris, the Democrats' vice presidential candidate, said she “would not trust his word” on getting the vaccine. “I would trust the word of public health experts and scientists, but not Donald Trump,” Harris said. Democratic presidential candidate Joe Biden amplified Harris' comments Monday after he was asked if he would get a vaccine for COVID-19, the disease caused by the novel coronavirus. Biden said he would take a vaccine but wants to see what the scientists have to say, too. "This is the political season, they're going to criticize anything that the president is involved with," said Meadows. "I can tell you it's good science and good doctors and great companies that are actually working hand in glove to try to deliver something in record speed." Under a program President Donald Trump calls “Operation Warp Speed,” the goal is to have 300 million doses of a coronavirus vaccine in stock by January. He has spent hundreds of billions of dollars on what amounts to a huge gamble since vaccine development usually takes years. Concerns exist about political influence over development of a vaccine, and whether one produced under this process will be safe and effective. Dr. Anthony Fauci, the government’s top infectious-disease expert and a member of the White House coronavirus task force, told CNN last week that it is unlikely but “not impossible” that a vaccine could win approval in October, instead of November or December. Fauci added that he's “pretty sure” a vaccine would not be approved for Americans unless it was both safe and effective. Stephen Hahn, commissioner of the Food and Drug Administration, has said the agency would not cut corners as it evaluates vaccines, but would aim to expedite its work. He told the Financial Times last week that it might be “appropriate" to approve a vaccine before clinical trials were complete if the benefits outweighed the risks. Subscribe to our YouTube channel: https://bit.ly/2TwO8Gm QUICKTAKE ON SOCIAL: Follow QuickTake on Twitter: twitter.com/quicktake Like QuickTake on Facebook: facebook.com/quicktake Follow QuickTake on Instagram: instagram.com/quicktake Subscribe to our newsletter: https://bit.ly/2FJ0oQZ Email us at [email protected] QuickTake by Bloomberg is a global news network delivering up-to-the-minute analysis on the biggest news, trends and ideas for a new generation of leaders.