In the U.K., public health officials are now trying to get a first dose of the coronavirus vaccine into as many people as possible. To do that, they're changing the timeline for administering the vaccine. Some leading public health officials are suggesting we try the same strategy here in Massachusetts. GBH News Reporter Craig LeMoult discussed the proposal with GBH All Things Considered Host Arun Rath. This transcript has been edited for clarity.

Arun Rath: So what is the proposal, exactly?

Craig LeMoult: Well, there's been a few different ideas, actually, that public health experts have been floating recently, and they're generating some real debate. One was cutting the vaccine dose in half, so there's twice as much to go around. And there's some data suggesting that might have the same efficacy, but it's unproven at this point. The vaccines are designed so that people get a second shot after a few weeks. It's 28 days for Moderna, 21 days for the Pfizer vaccine. The idea that seems to be getting the most traction right now is the idea of lengthening the time between the doses. So this is actually what they're trying in Britain. They're giving the first shot out to as many people as possible. And then, once it's widely distributed and more vaccine is made, they're going to start giving the second doses, and that could take months. And that hasn't been studied in the clinical trials. Dr. Mark Lipsitch supports this idea. He's at the Harvard T.H. Chan School of Public Health, and he's on Gov. Baker's vaccine advisory committee.

Clip from Dr. Mark Lipsitch: My understanding is that the choice of the three to four weeks in the trials was made because they wanted to do the trials quicker and get an answer quicker, which was a very good reason to pick that interval. But there's nothing magical about those dates.

And he said there's no evidence the efficacy of the first shot would drop off sharply after a few weeks without that second shot.

Rath: Do we know what federal health officials have to say about this proposal?

LeMoult: On Monday, the FDA put out a statement saying they do not support any of the proposed changes to the vaccine dosing. The statement says the 28-day interval is what's been studied for the Moderna trial and there's just not adequate scientific evidence to support changing that. They said we just can't say from the existing data that this provides as much protection. I talked about this with Dr. Lindsey Baden of Brigham and Women's Hospital. He's one of the lead investigators of the Moderna trial. The Brigham has enrolled more than 600 people in the trial. He agrees with the FDA. He says there's just not enough data right now to move forward with this other proposal, and he says this actually wouldn't address the real challenge we're having getting vaccinations right now, which is a distribution issue.

Clip from Dr. Lindsey Baden: The problem is, how do we give the doses that we already have? And after we give the doses that we have, then we can say, what do we need to do to extend it? But to say that let's give a unproven regimen when we can't even deliver the proven regimen that's available, I'm not sure we're thinking it through or solving the right problem.

On Thursday, Gov. Baker said there have been 329,000 vaccine doses shipped into the state. So far, less than half of those doses have been administered.

Rath: Thinking along the same lines, because vaccine distribution is on the states, it will be Massachusetts' decision on whether or not to do this. Do we have a sense of whether this different vaccine distribution regimen could happen in Massachusetts?

LeMoult: I talked to several hospitals this week that are currently giving vaccines to frontline health care workers, and they are all planning on giving the second dose. And Gov. Baker addressed this question earlier this week, whether the state could possibly change its strategy. He said a lot of people have already been really nervous about this whole vaccine development process, but it's now clear that the current protocol for the vaccine is about 95% effective. So he said before the state changes anything, you'd have to hear a detailed explanation from the federal government about how and why they'd mix things up. Right now, it doesn't look like that's coming. But one epidemiologist I spoke with this week who's actually against the idea acknowledged that in Britain, where they're already doing this, they're seeing a spike in cases of this new, more highly contagious variant of the coronavirus. He said we could be seeing that in a couple of weeks, and that could change the whole calculus about whether to try something different.