PHILADELPHIA: US President Donald Trump said Tuesday that a coronavirus vaccine may be available within a month -- an acceleration of even his own surprisingly optimistic predictions -- but added that the pandemic could go away by itself.
"We're very close to having a vaccine," he told a town hall question-and-answer session with voters in Pennsylvania.
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"We're within weeks of getting it you know -- could be three weeks, four weeks," he said.
Only hours earlier on Tuesday morning, Trump had said a vaccine could come in "four weeks, it could be eight weeks."
Democrats have expressed concern that Trump is putting political pressure on government health regulators and scientists to approve a rushed vaccine in time to help turn around his uphill bid for reelection against challenger Joe Biden on November 3.
Experts including top US government infectious diseases doctor Anthony Fauci say vaccine approval is more likely toward the end of the year.
At the town hall Trump was asked why he'd downplayed the gravity of the Covid-19 pandemic, which has now killed close to 200,000 people in the US.
Trump replied by saying: "I didn't downplay it. I actually, in many ways, I up-played it in terms of action."
But Trump himself told journalist Bob Woodward during taped interviews for the new book "Rage" -- published Tuesday -- that he had deliberately decided to "play it down" to avoid alarming Americans.

CHENNAI: In a boost for students who aspire to study MBBS in Tamil Nadu, the revised state board textbooks have covered almost all questions in NEET this year. An analysis of the NEET 2020 question paper has revealed that the new textbooks covered 97% of questions.

The state government had revised the state board syllabus and introduced updated textbooks for Class XI in 2018-19 and for Class XII in 2019-20.
After a delay of four months, the entrance test was held on September 13. A team of subject experts analysed the paper and has provided the page numbers from physics, chemistry and biology textbooks from where the questions were asked.
Class XI and XII textbooks have covered 174 out of 180 questions, a big improvement from 2017 when around 60% questions were covered by the old syllabus.
Experts said even an average student who prepared only with textbooks would easily score above 300 in NEET this year as more than 60% questions were direct questions from the textbooks.
“Tamil Nadu state board students should not feel inferior to CBSE students. The new textbook has bridged the gap and both have a level-playing field,” said professor Rita John, head, department of theoretical physics, University of Madras.
The state board textbooks covered 99% of questions in physics. Out of 90 questions in the biology section, 87 were covered by state board textbooks.
“An analysis of the question paper revealed that the state board biology textbooks have covered more questions than NCERT textbooks in NEET this year,” S Shameem, deputy director, State Council of Educational Research and Training (SCERT).
In chemistry, 43 out of 45 questions were asked from the textbooks. “If students understand the concepts, they can answer all the 45 questions,” a subject expert said.
The new textbooks are vastly improved following the revision in syllabus. “These are interactive textbooks and can lead to other online resources for students who are interested to learn more,” Shameem said.