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Experts split on when to release vaccine doses: all now or some later?

A state-operated site opened at the Jacob K.

A state-operated site opened at the Jacob K. Javits Convention Center on Wednesday for COVID-19 vaccinations. Credit: Don Pollard/Office of Governor Andrew M. Cuomo

Facing a finite supply of the vaccines that are key to halting the coronavirus pandemic, clinicians, policymakers and epidemiologists are split.

Should one dose be held back for every one administered? Or should the nation’s supply all be rushed out now?

Holding back would leave enough shots to complete the two-dose vaccination series, which confers the full, 95% immunity for everyone who also gets the first shot. Releasing the whole supply now would mean more people are vaccinated sooner — and thus given some protection, anticipated to be as high as 50% after the first dose — but gambling that enough second doses will be available down the road.

"It would be great to release more vaccine, but my hope is that if that plan is adopted, that there is also the assurance that there can also be the focus on the development of more vaccine so that people can, with confidence, be able to receive their second dose," said Dr. David Hirschwerk, an infectious disease specialist at Northwell Health who practices on the Manhasset campus. "If there is some delay in that second dose — be it by days or weeks — that probably is still OK, but if the delay of the second dose occurs much longer than that, there is less certainty, because that strategy hasn’t been studied."

In the clinical trials of the two vaccines in the United States — by Pfizer and Moderna — the shots were administered weeks apart; efficacy over longer periods wasn't tested, Hirschwerk said. Regarding that longer delay, Hirschwerk warned, "We are in somewhat uncharted territory."

Considering the pros and cons — and the sluggish pace at which the vaccination has been rolled out — Hirschwerk said all the vaccines should be released, while manufacturing and distribution of enough supplies for a second dose intensified.

With the injection of the first dose, Hirschwerk said, the body is given MRNA, a molecular road map, to prompt the production of coronas — spiked proteins — the kind the virus itself would use to attach to human cells. Thus, the body knows what to look out for if exposed in the future to the actual virus and its spikes. That first vaccine dose reduces one’s chances of infection, upon being exposed to the virus, to about 50%.

The second dose — ideally delivered 21 days later for the Pfizer vaccine and 28 days later for Moderna's — triggers a more robust immune response, because the body recognizes the virus’s coronas, bringing protection up to about 95%, said Hirschwerk, who has already received each of his doses.

Arthur Caplan, a bioethicist and professor at New York University Langone Medical Center, said he’d recommend releasing some of the supply — perhaps 25 million doses of about 100 million in the pipeline — but holding back some in case logistical logjams persist, as has happened since the vaccine became available in December in the United States.

"It’s great to say, ‘hey, let’s release more vaccine and give it out to more people and worry later about second doses,’ but right now we can’t even get out what we got," he said. "So that is the number-one ethics challenge: It isn’t just having supply, it’s having logistics to distribute it."

Earlier this week, the Trump administration was said to be reversing course to direct the immediate release of doses being held in reserve, effectively adopting a proposal by President-elect Joe Biden's incoming administration.

Mayor Bill de Blasio, speaking Wednesday at his daily news conference, said the city is expected to run out of the vaccine at some point next week, even with normally scheduled delivery, barring "a major new resupply, because so many New Yorkers want the vaccine." He urged the release of all doses, which are identical and interchangeable, whether given as a first or second dose.

"Holding back vaccine, when we have tens of thousands of New Yorkers, ready to be vaccinated right now, makes no sense at all. So, I'm calling on the federal government, release everything you can give us, we need it," he said. "And we need to speed up this system going forward because we're going to continue to build."

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