Fragile Covid-19 Vaccine Rolled Out in the U.K. Tests Global Supply Network

Workers at the Pfizer Inc. plant in Puurs, Belgium, loaded thousands of vials of the liquid, stored at nearly 100 degrees below zero Fahrenheit, into custom-made thermally protected shipping containers and packed with dry ice. Loaded onto anonymous trucks, they crossed 125 miles to the French coast and sped by train under the English Channel. By Thursday evening, three trucks were heading across the U.K. and a fourth was crossing the Irish Sea.

Tightly coordinated, this logistics chain is probably one of the world’s easiest.

For vaccines to halt then reverse the pandemic, similar drills must occur thousands of times over, all around the world, in places far less organized than Northern Europe. Countries and logistics companies are scrambling to prepare for the unprecedented challenge of shipping millions—eventually billions—of doses at carefully controlled temperatures. Some countries, particularly poor ones with weak infrastructure and governance in places like Africa, could see big delays. Britain itself faces a looming threat from Brexit, which risks causing long delays at its borders.

Even as countries including the U.S. authorize vaccines and begin inoculations, the U.K. will emerge as a laboratory for what is possible at high speed and what might go wrong.

“The U.K. is an ideal test for the roll out: a developed country not far from the production site with a good health service and a dense population,” said Michael Breen, director of infectious diseases and ophthalmology at GlobalData, a data analytics company.

Other countries are close behind Britain. The Food and Drug Administration on Tuesday said that the vaccine being distributed in the U.K., produced by Pfizer and its German partner, BioNTech SE, had met its success criteria in a clinical study, potentially allowing the U.S. to follow Britain in administering shots as soon as this weekend. Canadian officials said Monday they could begin vaccinations as soon as next week.

Russia this week started giving shots of its own Sputnik V vaccine to health workers and others but, like an earlier vaccine being offered in China, it hasn’t undergone full clinical trials.

Pfizer has practiced its transportation logistics on boats, trucks and planes, said Mike McDermott, Pfizer’s global-supply president who is overseeing the manufacturing and distribution.

“We’re quite confident,” he said in an interview Tuesday. “There’s always anticipation when you’re actually sending the live product to your first paying customer. In our case that was the U.K. The shipment went incredibly well.”

Pfizer’s plant in Puurs, Belgium, began producing vaccine doses months ago and storing them in ultracold freezers on site. The fragile vaccine needs to be stored at around -70 degrees Celsius (-94 degrees Fahrenheit) to maintain its integrity, which makes transportation a huge challenge. That is the lowest temperature among the leading Western vaccine contenders.

Moderna Inc.’s rival vaccine candidate must be shipped and stored at -20C, while AstraZeneca PLC’s candidate doesn’t require subzero temperatures. Moderna’s vaccine is under evaluation by the FDA.

Workers at the Pfizer facility were waiting until the last possible moment to load the vaccine, said Mr. McDermott. They waited eight hours, as the U.K. government has to authorize not just the vaccine itself, but each batch. By the time the batches were cleared, the truck drivers were about to exceed the amount of time they could work, so they had to call a replacement crew, who arrived in time to get the shipment out.

The vaccine doses were packed into custom-designed “thermal shippers,” which are each about the size of two carry-on suitcases and designed to hold nearly 5,000 doses at close to -70C for up to 30 days as long as fresh dry ice is added. Small glass vials that contain five doses each are stored in trays that are stacked like pizza boxes inside the shipper and covered with dry ice pellets.

Each shipper contains a device about the size of a cellphone that functions as a thermal sensor and GPS monitor, and can even tell if the box is opened. It feeds information to a Pfizer control center, allowing the company to make sure the shipment is sticking to its planned route and maintaining its required temperature. An alert is triggered if the driver deviates from the route, even for a rest stop.

Security is a concern. International police agencies have warned organized crime gangs could seek to hijack shipments and steal vaccines. The cybersecurity unit of International Business Machines Corp. said Thursday that hackers had been targeting companies and organizations connected with the “cold chain,” the part of the vaccine supply chain that ensures the vaccines are stored at the correct temperatures.

The first Pfizer vaccines were carried Thursday morning by private trucking companies 125 miles to Coquelles in northern France, according to people familiar with the journey. There, the trucks transferred to freight trains for the 35-minute journey through a tunnel under the English Channel to Folkestone, the people said.

Many more vaccine shipments are expected to travel across Europe by truck on the continent’s dense road network. But the air industry is already gearing up to transport billions of doses at a time when the number of flights world-wide has been severely curtailed by a lack of passengers. Some airlines have converted passenger planes to ship vaccines by removing seats.

The International Air Transport Association, a trade group, said a single dose for each of the world’s 7.8 billion people would fill 8,000 Boeing 747 cargo aircraft. The Pfizer and Moderna vaccines require two shots per person. Some logistics companies said that figure looks high, and that it remains too early to say how much strain will be placed on logistics networks.

“The biggest problem is that we don’t know how much is going to be sent,” said Koen Gouweloose, chief executive of cargo services in Belgium for Swissport International AG. Brussels Airport is one of the most advanced in Europe for transporting pharmaceutical products at controlled temperatures. Swissport, the Zurich-based airport services provider last year opened a $12 million “pharma center” at Brussels Airport that can take vaccines from trucks, store them and put them on planes all while controlling their temperatures.

Swissport built the facility because Belgium, with a population of some 11.5 million, is the world’s third-largest exporter of pharmaceutical products, valued at €42.9 billion, equivalent to $52 billion, in 2018, according to pharma.be, an industry umbrella organization. Global pharmaceutical giants have been attracted to the region by the presence of leading universities and transport links across Europe.

The airport has experience handling vaccines for Ebola that also had to be stored at ultracold temperatures for shipping to Africa. The World Health Organization said in November that Africa is far from ready for a mass immunization drive, hampered by poor infrastructure and weak governance.

“The final mile could be the most difficult,” said Mr. Gouweloose.

For the vaccines heading to the U.K., the journey was made simpler by the fact they remained on the same trucks. But potential hurdles lie ahead, notably the uncertainty over a Brexit deal between the U.K. and the European Union, which the U.K. is leaving. If no agreement on their future relationship is reached by the deadline at the end of the year, officials worry that trucks could back up on either side of the English Channel.

The British government said Tuesday it could use the military, including aircraft, to deliver vaccines if supplies were delayed.

“This is such an important product, it’s probably perhaps the most important product, so we will look to ensure that those supplies are available in the U.K., in whatever circumstance,” James Cleverly, a minister in the U.K. Foreign and Commonwealth Office, told the British Broadcasting Corporation. Some 13,500 military personnel were on standby to assist with the rollout, said Minister for the Armed Forces James Heappey.

Once in England on Thursday, the trucks headed to warehouses owned by the government and run by Movianto, a health-care logistics company. The warehouses were stocked with ultracold freezers purchased by the government, according to Martin Sawer, executive director of the Healthcare Distribution Association, which represents pharmaceutical suppliers that are involved in distribution of the vaccine.

Some freezers have been lent to a network of smaller warehouses run by the HDA’s members, which will receive and store doses of the vaccine until they begin receiving requests from state-run hospitals and vaccination centers.

When requests arrive, warehouse staff move the vaccines from freezers to cold-storage rooms—large walk-in refrigerators—where the vials defrost over three hours.

From there, refrigerated trucks will carry them to the hospitals, pharmacies, doctors’ offices and sports halls that make up the patchwork of the U.K.’s mass-vaccination centers.

In the initial phase, the vaccine’s complex requirements mean it will be mostly limited to sites that have the freezers to store it. Fifty hospital hubs across England and a small number of other sites across Scotland, Wales and Northern Ireland are the first to administer the vaccine. In the coming weeks, the U.K. hopes to send vaccines to more than 1,500 smaller vaccination centers run out of doctor’s surgeries and pharmacies.

Defrosted vials of vaccine remain stable for up to five days if kept at 2-8 degrees Celsius. They can be transported only twice and for a maximum of 12 hours on the road, said Mr. Sawer. That means not only a race to get vaccines to their intended destinations, but a need for clear communication between vaccination centers and warehouses to prevent wastage.

“It is all about the flow. There is no point in us defrosting them if there are not enough patients at the other end,” said Mr. Sawer.

At a side room at a sports center in Cardiff, Wales, on Tuesday, defrosted vaccines—which had arrived just the day before—were being removed from cold storage and prepared for injection. A pharmacist on hand regularly checked the temperature of stored vaccines while staff followed a careful procedure, set out in government guidelines, of inverting the vials 10 times, before mixing their contents with a solution of sodium chloride, and, again inverting 10 times.

In the hall, vaccine doses ready to be administered were brought to booths divided by blue hospital curtains, lining the walls. Patients sat waiting in chairs positioned on crosses marked on the floor to keep them safely apart. Each was escorted by a nurse to a booth to receive their initial dose.

Appointments were set at 15-minute intervals, despite nurses needing just two minutes to confirm personal details and administer the shot. That is because staff wanted to allow for any “teething problems,” said Lynne Cronin, a nurse administering shots.

“It’s better to hold things off and to see how things progress, rather than trying to cram things in,” said Mrs. Cronin.

Paul Arnold, a 47-year-old hospital worker who received the shot, said it was quick and easy.

“The hardest part was the traffic on the way in,” he said.

Mr. Arnold said he was looking forward to seeing his elderly mother again for the first time in nearly a year. He has been unable to work in the roles most exposed to Covid-19 patients as an autoimmune condition makes him particularly vulnerable to the disease.

“The worst of it has been a bit of a sore arm and a headache,” said Darren Cooke, a senior nurse at an intensive-care unit at the University Hospital of Wales in Cardiff, as he waited in the sports hall after receiving his shot.

Mr. Cooke, who was one of the first to contract Covid-19 at his workplace in March, said morale at his ward is low after months of dealing with the pandemic.

“Everyone is exhausted from the relentless workload and the PPE requirements. But I hope that, maybe, soon we can get back to some sense of normality.”

Write to James Marson at james.marson@wsj.com, Will Horner at William.Horner@wsj.com and Jared S. Hopkins at jared.hopkins@wsj.com

Corrections & Amplifications
Moderna’s vaccine is currently under evaluation by the FDA. An earlier version of this article incorrectly said that vaccines from both AstraZeneca and Moderna are under evaluation. (Corrected on Dec. 8)