The pace of the U.S. COVID-19 vaccine rollout should soon pick up after the Trump administration failed to meet its commitment of vaccinating 20 million Americans by the end of 2020, a top official at the U.S. Centers for Disease Control and Prevention said.

"Now that the holiday is over, now that health departments, hospitals and the long-term care facilities have a little bit of experience with these vaccines, I really expect the pace of administration to go up pretty massively in the next couple weeks," Nancy Messonnier, director of the CDC's National Center for Immunization and Respiratory Diseases, said Jan. 5 during an online forum hosted by Stat News.

While President Donald Trump, Health and Human Services Secretary Alex Azar and Operation Warp Speed Chief Scientific Adviser Moncef Slaoui had repeatedly vowed to vaccinate 20 million Americans by Dec. 31, 2020, the administration fell far short of that commitment.

On Jan. 5, the CDC reported that just over 17 million doses of the vaccines from Pfizer Inc. and Moderna Inc. had been distributed in the U.S., and only 4.8 million had been administered. Over 3.2 million of those distributed doses were provided to U.S. long-term care facilities, though only 429,066 had been administered, according to the CDC's online tracking system.

Both the Pfizer and Moderna vaccines are two-dose shots.

The second dose of Pfizer's vaccine, which it developed with BioNTech SE, must be given 21 days after the first injection. For Moderna's product, which it developed with the U.S. National Institute of Allergy and Infectious Diseases, the second dose must be given 28 days after the first shot.

Both vaccines are based on messenger RNA platforms — the first shots authorized in the U.S. using that technology. Messenger RNA, or mRNA, plays a fundamental role in human biology, transferring the instructions stored in DNA to make the proteins required in every living cell.

Trump, Azar and Slaoui had started out last summer promising 300 million COVID-19 vaccine doses distributed to U.S. states and territories before the end of 2020. They later sliced that number down to 100 million. Then, in November 2020, they said 40 million would be delivered, with half of those shots being held in reserve for people getting the second dose.

But Messonnier said many states had "planned initially to have a slightly slower rollout so they can get used to the vaccine and make sure that we were using this precious commodity really carefully."

Not only are the vaccines based on new technology, Pfizer's product, in particular, has very different storage and handling requirements than other shots, she said. Plus, the vaccines were launched amid an ongoing pandemic, where many state and local health departments are dealing with surges in COVID-19.

"It's the early stages of a really complicated task but a task that we're up for," Messonnier said.

Like top officials at the U.S. Food and Drug Administration, Messonnier rejected suggestions that the second doses of the Pfizer and Moderna vaccines could be delayed or the volume of the doses cut in half to vaccinate more people.

"I really think that we have to follow the science," she said. "Right now, the science says that this is a two-dose series."

Easy access

For now, the CDC is focused on helping states and territories ensure access to vaccinations will be easy and that all communities are prepared when their allotments of the shots arrive so that people can "roll up their sleeves and get vaccinated," Messonnier said.

"And that needs a massive upsurge in a lot of different things all at once," she said.

The latest round of stimulus funding enacted by Congress in late December 2020 should help states escalate their vaccination programs, Messonnier said.

The $900 billion included nearly $9 billion for COVID-19 vaccination programs — the amount the Association of State and Territorial Health Officials said would be needed.

President-elect Joe Biden has vowed to seek additional funds for COVID-19 vaccination administration and education programs.

"There are still lots of myths and misinformation circulating and we need to rapidly get people accurate information," Messonnier said, emphasizing the need for education efforts to be substantially increased.

Getting the majority of the U.S. vaccinated is "going to take a whole-of-society, a whole community effort," in which multiple venues will be needed, Messonnier said.

Communities should be calling on local businesses to help set up vaccination programs for their employees and their families, she said. Other mass vaccination sites could include schools, churches and sports arenas, though mask-wearing and social distancing must be adhered to at all of those locations, she said.

Allergic reactions

Messonnier acknowledged that all sites administering the Pfizer and Moderna vaccines must be equipped with treatments for anaphylaxis such as epinephrine and personnel who know how to address and treat allergic reactions.

There have been more than a dozen cases of anaphylaxis linked to the two mRNA shots since vaccination started in the U.S., she said.

The CDC is expected to publish a Morbidity and Mortality Weekly Report Jan. 6 with details about those allergic reactions, Messonnier said.

But given there have been over 4 million of the mRNA shots administered in the U.S. and 2,000 to 3,000 daily American deaths from COVID-19, "if you do the math, I would say that we still think that this is a manageable number" of allergic reactions, she said.

"All of these things are bumps in the road. All of these things are things that we need to manage but none of them are things that should stop us," Messonnier said. Officials do not want to see any COVID-19 vaccine doses go to waste or sitting on shelves, she emphasized.