Health workers responding to an Ebola outbreak in remote parts of Congo two years ago faced a quandary: trial vaccines for the deadly disease had to be stored at subfreezing temperatures as they traveled deep into tropical forests by helicopter or motorcycle.
America’s highways and byways are far more advanced than Congo’s, but the “cold chain” is one of several concerns for federal officials as they assemble a massive vaccination campaign to defeat COVID-19.
Messenger RNA vaccines being developed by companies such as Pfizer and Moderna must be held in temperatures as low as minus-100 degrees Fahrenheit.
“It’s an issue,” said Paul Offit, a pediatrics professor at the University of Pennsylvania and member of the Food and Drug Administration’s vaccine advisory panel. He said tens of millions of vaccine doses are slated to go out in the first round of delivery but risk being spoiled if they aren’t handled correctly.
“That is a massive effort,” he said. “It’s going to be interesting, how they plan on maintaining the potency from tarmac to arm.”
Company officials say they are confident in their methods for safeguarding the shots.
Administration officials announced Thursday that they soon will be awarding contracts to distributors as they remain on track for delivering doses no later than January. Each contract recipient will have to demonstrate the ability to store and transport shots the right way.
In fact, “one of our manufacturers is developing its own containers and method,” said Paul Mango, deputy chief of staff for policy at the Department of Health and Human Services.
It’s just one facet of the sprawling and unprecedented effort, including calculations on who will get the shots first.
“There won’t be enough on day one for everyone in the United States,” Mr. Mango said.
Distribution of the initial millions of doses will be prioritized. Panels looking at this are focused on the elderly, such as nursing home residents, and health care workers and other essential employees who interact with the public.
The coronavirus discovered in Wuhan, China, in December has upended normal life. The disease it causes, COVID-19, has killed more than 166,000 people in the U.S.
Operation Warp Speed, an initiative of the Trump administration, is working to expedite the development, manufacture and distribution of a vaccine in record time. Officials said they will not cut corners in vetting clinical data in the coming weeks and months, and there is never a 100% guarantee of landing a successful vaccine.
However, “we believe we are maximizing our probability of success,” Mr. Mango said.
As part of the effort, the administration has extended manufacturing support to six leading candidates: AstraZeneca, Johnson & Johnson, Moderna, Novavax, Pfizer and Sanofi/GSK.
Many of them are in massive phase three trials involving tens of thousands of human participants.
National Institutes of Health Director Francis Collins said he feels confident about the effort because there are so many options.
“If we were putting all of our efforts in a single vaccine, I’d be really worried right now,” he said, adding that there is still “plenty of illness” in the U.S. to conduct trials domestically.
Officials on Thursday said the Department of Defense will be “very involved” in the manufacturing of the immense amount of raw materials that have to be acquired for the effort.
“Those factories have to be equipped, those workers have to be trained,” Mr. Mango said.
The Centers for Disease Control and Prevention will track patients and communicate with states, the administration said. The agency’s advisory committee on immunization practices is working on who will get priority for the shots.
Early deliberations suggest health workers will be first in line, along with essential employees including transit workers and people who staff meatpacking plants. The next phase would include people at risk for severe effects such as nursing home residents. A third phase would consist of the general public.
The committee is still drawing the lines, and some of the distribution will depend on how the third-phase vaccine trials go, as scientists see which shots work in certain populations.
The advisory group is also working on ways to ensure that shots don’t sit in the freezer, helping no one, after priority groups are served. The government learned that lesson during the H1N1 vaccination effort in 2009, said William Schaffner, an infectious diseases specialist at Vanderbilt University.
Nate Wardle, a spokesman for the Pennsylvania Health Department, said that “while guidance will come from the federal level, we expect that decisions on prioritization will ultimately be made at the state/local jurisdiction.”
He said Pennsylvania has protocols to make sure vaccines are properly stored and their cold chains maintained.
“The COVID-19 vaccine is a novel vaccine, and we expect it will be unlike anything we have seen before. We are working to finalize our vaccination plan and protocols with our partners, including at the federal level, to ensure we are prepared for all aspects of this vaccine,” he said.
A vaccine is considered the most important tool in defeating COVID-19, which has killed nearly 750,000 people worldwide.
Countries and U.S. states have taken a series of drastic measures to keep people apart and slow transmission, resulting in economic downturns. Cases flare up in places where preventive behaviors are lax and gaps occur in testing and tracing.
The seven-day rolling average of new U.S. cases stands at fewer than 54,000 per day, down from nearly 66,000 three weeks ago.
Adm. Brett Giroir, the coronavirus testing czar, said Thursday that the recent drop in nationwide cases is not a result of fluctuations in testing. He said less than 7% of tests are returning positive, compared with 9% on July 23.
“We have decreased cases because we have decreased cases,” Adm. Giroir said.
More than 130 vaccines are in development around the world for the coronavirus, including eight in phase three human trials.
Russian President Vladimir Putin said Tuesday that his country had approved the world’s first coronavirus vaccine and that one of his adult daughters was among the first to get a dose. American officials greeted the news with skepticism.
Dr. Collins said Russia appeared to declare victory early from limited trials. If anything, he said, the Russians appear to be behind the American and European scientists who are engaged in rigorous phase three trials.
Vaccines that can be stored at ordinary refrigerator temperatures are much easier to deliver than those that have to be stored at subzero temperatures.
Pfizer said its potential COVID-19 vaccine will need to be stored around minus-100 degrees Fahrenheit, significantly lower than the average winter temperature at the South Pole. The company said, though, that it hopes to have a “lyophilized formulated” version by the end of next year that can be stored at much higher degrees.
Pfizer spokeswoman Kim A. Bencker said the company has “a tremendous amount of experience and confidence” to deliver and store doses.
She said Pfizer is working closely with the government on contracts and that points of delivery may vary from hospitals and outpatient clinics to mass community locations and large pharmacies.
“We have developed detailed logistical plans and tools to support effective vaccine transport, storage and temperature monitoring. Our distribution is built on a flexible just-in-time system which will ship the frozen vials to the point of vaccination,” Ms. Bencker said.
The company said it has developed packaging and storage innovations to fit a range of locations, including “specially designed, temperature-controlled containers” that maintain storage conditions for up to 10 days.
Amesh Adalja, a senior scholar at the Johns Hopkins University Center for Health Security, said safeguarding vaccines will be a particular concern in developing countries as COVID-19 remains a global crisis.
“Maintaining the cold chain has been really important,” he said, “when you think about developing country vaccine delivery where electricity may be spotty.”
Gavi, The Vaccine Alliance, said it is planning for “all eventualities” as it prepares for its role in combating COVID-19 through public-private partnerships in developing countries.
“Ten years ago, delivering a COVID-19 vaccine globally would have been a massive challenge, potentially impossible,” the alliance said. “Now after two decades of work by Gavi and our partners, most countries’ cold chain is in good shape.”