And everyone is still hoping for a vaccineincluding me.

But Im also cautious.

When I first wroteabout the vaccine back in March, the vaccine development process was just beginning.

Person smiling while getting vaccinated

Photographer: Heather Hazzan; Wardrobe: Ronald Burton; Props: Campbell Pearson; Hair: Hide Suzuki; Makeup: Deanna Melluso at See Management. Shot on location at One Medical.

Phase 3, then, are larger studies with tens of thousands of volunteers.

There are eight candidates in some part of this phase.

Here are their answers to the most common COVID-19 vaccine questions.

First: Which vaccines look the most promising?

This includes theAstraZeneca/University of Oxford vaccineand theJohnson & Johnson vaccine.

Two other candidate vaccines fromNoravaxandSanofi-GSKuse proteins from SARS-CoV-2.

Even those that may look good in Phase 2arent necessarily guaranteedsuccessful Phase 3 trials.

Thats only one potential hurdle with a COVID-19 vaccine.

That might be a tough combination to find.

When will a COVID-19 vaccine be available?

This is also still very much up in the air.

(Seeing a pattern?)

There are lots of ambitious estimates for this that, unfortunately, seem unlikely to come to pass.

And thatsthe first vaccine to have reached this milestoneothers lag behind Modernas timeline.

And, for this reason, none of the virologists I spoke with favored this suggestion.

What obstacles are we facing with distribution?

Then theres the issue of cost.

In the U.S., that will depend on approval by the Advisory Committee of Immunization Practices (ACIP).

Where adults will receive vaccines is another pressing distribution question: At their workplaces?

And will we need one dose or two?

That can only be determined by following vaccine recipients over time.

Who should get a COVID-19 vaccine first?

Its likely these groups will have first priority for vaccination, followed by the general public.

Will enough people even use the vaccine?

Once thevaccineis eventually released, the natural next concern is: Will people get it?

The vast majority of public health experts who do infectious disease work day in and day out certainly will.

Im not encouraging people to do something I wouldnt do myself, says Rasmussen.

Morrison urges trust in the scientists who are carrying out this research every day.

Neither have other scientists who are committed to doing their best to get us out of this situation.

With that said, studies have already suggested that hesitancy about this vaccine is high.

Some misgivings may come from the framing of the race to the vaccine.

How should we stay safe in the meantime?

Finally, unfortunately,a vaccine wont be a panacea.

When a vaccine is approved, it wont be immediately available and it wont immediately end the pandemic.