The New York Times photo by Erin Scott / President Donald Trump speaks in a news briefing Wednesday to dismiss his CDC chief's testimony earlier that day about the timetable for a hoped-for COVID-19 vaccine.

We have to wonder when the conservative right will stop believing a president who cannot keep his stories straight for even a week at a time.

A president who tells America — despite expert conclusions otherwise — that a vaccine will be out before the November election and widely distributed by the end of the year, though his director of the Centers for Disease Control and Prevention, Dr. Robert R. Redfield, the day before told a Senate committee — ahem, no it won't.

A president who completely dismisses that expert CDC testimony and with a straight face tells Americans that the longtime disease specialist "didn't understand the question."

The same president who told a reporter in February that the novel coronavirus is airborne and dangerous, then days later and for months told Americans it's nothing.

Redfield, as a matter of fact, told the Senate committee Wednesday that a vaccine would not be widely available until at least the middle of 2021 and that masks are and would continue to be so vital in fighting the disease caused by COVID-19 that they may even be more important than a vaccine.

Specifically, Redfield testified that a vaccine could be — could be — available for first responders and vulnerable populations by November or December, but that it will take six to nine months before it can be distributed nationally.

And don't just take Redfield's word for it. Moncef Slaoui, the chief scientific adviser to Operation Warp Speed, the project tasked with developing a vaccine by January, has said it is "extremely unlikely" that widespread distribution will be possible by October or November.

But Trump can't stop spinning his own bubble of baloney.

"I think he [Redfield] made a mistake when he said that [to the Senate committee]," Trump told reporters and Americans. "It's just incorrect information." A vaccine would go "to the general public immediately," and "under no circumstance will it be as late as the doctor said."

As for Redfield's advice that masks may be more useful than a vaccine, Trump said again: "He made a mistake." Trump maintained that a "vaccine is much more effective than the masks."

Who does the president trust about the effectiveness of masks? Why, restaurant waiters. Of course.

And then Trump, who in the past has praised anti-vaxxers, tried to project an anti-vaxxer attitude onto his November presidential opponent, former vice president Joe Biden, who has never — NEVER — been anti-vaccine.

What Biden and his running mate Kamala Harris have been is anti-Trump, and what they have said is that they would not trust what Trump said about a COVID-19 vaccine. Rather, they would check first and depend on the word of the health experts and scientists.

"I trust vaccines. I trust scientists," Biden said Wednesday in Delaware. "But I don't trust Donald Trump, and at this moment the American people can't either."

Americans' approval for Trump's handling of COVID-19 stands at a lowly 35%, according to an ABC News/Ipsos poll released Sunday, compared with a 65% disapproval. It is the fourth straight poll with similar results since early July.

Biden further said a vaccine for COVID-19 must be developed and distributed free of political pressure. He accused Trump of "feckless inaction" and said scientists must make the decisions about when a vaccine is safe and how it should be distributed.

He said the development of a vaccine won't follow a political calendar, despite Trump's assurances that a vaccine will be completed within weeks.

Biden also said he would listen to medical experts, but he would be inclined to distribute a vaccine initially to first responders, doctors and nurses. Then, Biden said, he would distribute it to populations at greatest risk, such as the elderly and people with preexisting conditions.

"It would be based upon the degree of exposure," Biden said. "It's got to be based on who is most vulnerable," rather than people with the biggest billfolds.

But Trump continues with his fairy tale. At a briefing Wednesday after Redfield's Senate remarks, Trump countered: "We will distribute at least 100 million vaccine doses by the end of 2020." He insisted it would not be limited at first to high-priority cases, as doctors have said.

And Trump went full-on political, suggesting that fatalities in states that vote for Democrats should not be counted: "If you take the blue states' deaths out, we are at a level I don't think anybody in the world would be at," he said.

It would be funny were it not so absurd.

Now, make no mistake. Certainly we all would like to see a COVID-19 vaccine safely and scientifically developed and distributed — yesterday, let alone by early November. But that is unrealistic.

Even if the science could be rushed that much — and it can't unless Trump treats it like he treated hydroxychloroquine — experts say a vaccine might not be widely available until well into 2021.

Why? Because there's a safety process that must be followed. Vaccines must be reviewed by the FDA, and no vaccine has been submitted yet for the FDA to review.

Even that may not happen by Trump's aggressive October estimate for distribution. What's more, whenever a vaccine is approved, it will take several more months to manufacture enough to begin vaccinating the general public.

Wishes aren't horses, even if the president keeps saying so.