Dr. Rick Bright told MSNBC on Wednesday that while the news from Pfizer was “encouraging”—noting that the vaccine appeared to show “remarkable effectiveness”—difficulties with the presidential transition period could mean it will take longer to distribute vaccinations around the country.

Once the Pfizer vaccine has been approved by public health authorities, “the hard stuff” will start Bright said.

“The vaccine doesn’t save your life, but vaccination does,” he told MSNBC. “Remember that vaccines don’t deliver themselves, we need to make sure that we have a complete vaccine campaign rollout. There are very limited doses of this vaccine available right now and it takes two doses per person to achieve sufficient immunity and protection from the virus. So we don’t have much vaccine to go around.”

“We’re going to have to make some very difficult decisions on who gets the vaccine first, how to identify those individuals, how those individuals know that they’re one of those priority groups. And then we have to make sure we distribute that vaccine to the health care providers who will deliver the vaccine.”

The Pfizer vaccine must be kept at extremely cold temperatures, which could pose a problem for the distribution effort in some areas of the United States.

“We might have several of those special freezers in some large communities or large cities such as New York,” Bright said. “But when you move out into rural communities or areas that are traditionally hard to reach with a vaccine, they don’t have that specialized equipment.

“President-elect Biden has made the promise and the commitment that when we roll out the vaccine and the therapeutics, it will be done in an equitable manner to make sure we’re reaching those people that are hard to reach. We need to make sure that the vaccine does get to the right people.”

As a result Bright said it is “absolutely critical” that the Biden transition team sit down with the Trump administration “today” to discuss the Pfizer trial, the technical aspects of the vaccine and the upcoming distribution campaign.

So far, President Donald Trump and his team have refused to concede the 2020 election. The General Services Administration (GSA) has yet to certify Biden as the winner, holding up the launch of the official transition process and limiting the ability of the Democrats to contact the agencies they will expecting to staff.

Bright said: “We have been held at an arm’s pace, we have no insight to the plans from this current administration. We do not even have direct access to the data. So the GSA delay of the ascertainment of this election is causing significant delays [at] this critical time point with regards to the rollout of the vaccine.”

On Wednesday, Pfizer said it had concluded a large, Phase III trial of its vaccine candidate, being developed in collaboration with German firm BioNTech, finding that it had an efficacy of 95 percent—slightly higher than an early analysis of results suggested.

While the data has yet to be shared with the public or published in a peer-reviewed scientific journal, Pfizer said the efficacy was consistent across different genders, ethnic backgrounds and ages—even among those over 65 years of age who are at high risk from COVID-19.

In addition, the company said the vaccine was very well tolerated by the study participants—of which there were more than 43,000—with no serious side effects reported.

Pfizer expects to submit an application for an Emergency Use Authorization (EUA) to the Food and Drug Administration (FDA) “within days” and will also share data with other regulatory agencies around the world.

Pfizer said it expects to produce around 50 million doses of the vaccine globally in 2020, and up to 1.3 billion by the end of 2021.

American biotechnology firm Moderna announced that their vaccine candidate was more than 94 percent effective based on an early analysis of evidence from an ongoing, Phase III trial.