2 charts from a top Wall Street bank reveal how drugmakers could deliver a coronavirus vaccine October surprise for Trump

• President Donald Trump says a $4 could be ready "right around" the time of the November elections.
• It's possible we'll have data by then showing that one or more experimental shots works.
• But it's exceedingly unlikely a vaccine will be widely available in 2020, given the manufacturing and distribution challenges.
• Morgan Stanley biotech analysts project the leading vaccine programs will produce crucial results in October or November. They see $4.

US President Donald Trump is making lofty claims about the potential for a $4 before the November elections.

On Thursday, he said a vaccine could be ready "$4" the November 3 contest. Earlier in the week, he said $4 "far in advance of the end of the year."

An effective coronavirus vaccine would be a huge step toward curbing the pandemic and helping people in the US get back to work. Plus, some of Trump's advisers think having a vaccine is essential for the president's reelection prospects, $4.

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To be clear, it's very unlikely that there will be a widely available coronavirus vaccine before the end of the year. The Trump administration's own vaccine effort, called Operation Warp Speed, has said that its goal is to have 300 million doses of a vaccine available in January. Most of these experimental shots are two-dose regimens, which further strains supply.

We could get crucial coronavirus-vaccine data in October

But it's possible that in October, we could get data showing that one or more experimental vaccines works to prevent the coronavirus or the disease it causes, COVID-19. The biotech company Moderna, for instance, has said that we could know whether its vaccine works $4, and Pfizer has said it could have data ready to show to US regulators that month as well, for a vaccine its created with the biotech BioNTech.

Based on that data, regulators at the Food and Drug Administration could decide to let some people at high risk for catching the disease, such as healthcare workers, get the shot. That might be just enough good news for Trump to declare vaccine victory and deliver an October surprise.

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Biotech analysts at Morgan Stanley laid out how that could happen in more detail in a recent note to investors. To be sure, they think it's more likely that we'll get conclusive data on vaccines from late-stage trials in people in November.

There's a narrow window for an October surprise

The potential for an October surprise hinges on how these trials are designed. Each trial involves about 30,000 volunteers, half who get a coronavirus vaccine, and half who don't. Over time, researchers watch to see how many people in each group get sick from the coronavirus.

Once a certain number of people get sick, the researchers run calculations to see whether the vaccine has helped or not. In at least Moderna's trials, the researchers take a look at the data several times over the course of the study. Since these data checks are based on how many people get sick, it's impossible to say for sure when they'll happen.

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But by analyzing the rate of coronavirus spread and several other factor, the analysts at Morgan Stanley created detailed timelines for the vaccine trials. They show that narrow window for an October surprise. We've annotated the timelines to show the most important part.

The Morgan Stanley analysts didn't provide a detailed timeline for the third leading vaccine effort, from AstraZeneca and researchers at University of Oxford. They said they think we could get data from that effort on a similar timeline to Pfizer and Moderna.

The Moderna timeline:

The Pfizer-BioNTech timeline:

Eliza Relman contributed reporting.