The “cold chain” is just one of the challenges in the spread of vaccines around the world.
There are many others: decisions on priority populations and databases to keep track of who got what vaccine, where and when. In addition, different vaccines may be more or less effective in different populations; and governments will need PR campaigns to convince people that vaccines are safe.
But the logistics of transporting and storing vaccines – taking them from the factory gate to the patient’s hand – are crucial. And since most vaccines are likely to require two doses, the needs of the whole chain must be repeated within weeks.
The Pfizer-BioNTech vaccine should be maintained at about -70 degrees Celsius (-94 degrees Fahrenheit) while being transported. This is 50 degrees Celsius colder than any other vaccine currently in use.
Moderna says her vaccine can be stored in freezers, which are usually available in pharmacies, and in the refrigerator for 30 days. But there are likely to be fewer doses of Moderna than Pfizer available next year.
Phase 3 studies have shown that both vaccines are about 95% effective, but the results have not yet been reviewed by regulators.
On Wednesday, the CEO of BioNTech, the German biotechnology company partnering with Pfizer, acknowledged the issue of temperature control.
“We are working on a formulation that can allow us to send the vaccine even perhaps at room temperature,” Ugur Sahin told CNN. “We believe that in the second half of 2021 we will come up with a wording that is comparable to any other type of vaccine.”
Meanwhile, US Secretary of Health and Humanitarian Affairs Alex Hazard believes the Moderna candidate is “more flexible” for settings as a local pharmacist. Pfizer, he said Monday, would be better suited for “a large institutional vaccination, say a whole hospital setting, several nursing homes at once.”
Pfizer plans to deliver up to 1.3 billion doses next year, requiring a lot of dry ice (solid carbon dioxide at about -78 degrees Celsius) and a lot of isothermal boxes. The cans contain up to 975 vials (4875 doses) and can be filled with dry ice for storage for up to 15 days.
Pfizer is testing the supply chain in four US states. Its chief executive, Albert Burla, said Wednesday that there were “zero concerns” about the cold chain’s requirements.
But sending such a vaccine can create major challenges. Dr Jarbas Barbosa, assistant director of the Pan American Health Organization, told CNN that “rural and urban areas in every country in the world are not ready to administer this vaccine today.”
“So who in the world is prepared? No one.”
One of the issues is the presence of dry ice.
Sam Rushing, president of Florida-based Advanced Cryogenics, told CNN that the United States already has a regional shortage.
US authorities are confident that there will be enough dry ice. Paul Ostrowski, director of supply, production and distribution for Operation Warp Speed, told CNN last week that the courier UPS was committed to “providing a supply of dry ice across America upon request.”
But Rushing warns that dry ice is not very easy to use and can be dangerous if stored improperly, especially indoors. The Federal Aviation Administration classifies it as a dangerous cargo.
Peter Gerber, CEO of Lufthansa Cargo, told CNN that the need for dry ice “obviously reduces transport capacity, because if you have to load more ice, you can’t load so much vaccine. And of course the procedures have to be very special to ensure that there is always this degree of cold. “
The American courier DHL adapts the distribution plans according to the specifications of each vaccine. David Goldberg, CEO of Global Forwarding US for the company, says that “there is a limit to the amount of dry ice used for an aircraft – usually 500-1000 kilograms, depending on a number of factors.”
Once arrived, Pfizer vials can be stored at between 2 and 8 degrees Celsius for up to five days before deteriorating. Pfizer says it has developed a “just-in-time system that will deliver frozen vials directly to the vaccination point.” It will also monitor the temperature of each box that is sent.
Julie Swan, a supply chain expert at North Carolina State University, says large hospital systems, which often have ultra-cool freezers, can play the role of distribution centers. But not all US states have them; Last week, Hawaii said none of the hospitals had such freezers.
Breaking consignments of frozen vaccine for rural areas or small groups of essential workers – without disturbing their temperature – would be another headache, Swan said.
When a vaccine needs to be used within a few days, providers will need to make sure they are ready. “You can’t just wait to see who shows up,” Swan told CNN. “And in fact, we still don’t have good data to determine where and which priority populations are.”
Prashant Yadav, a supply chain expert and senior fellow at the Center for Global Development, said: “The question is how soon we can start thinking about multiple packaging formats.”
Beyond the United States
If getting a frozen vaccine for tens of millions of people is a challenge in the United States, it is a far bigger problem for poorer countries.
Transport connections are slower and medical facilities are less equipped in the developing world. CO2 production is scarce, and the costs and dangers of sending huge amounts of dry ice are also an obstacle, Yadav said.
David Gitlin, CEO of Carrier Refrigeration Specialists, told CNN last week: “When you look at places like Africa and India, they just don’t have the cold chain infrastructure. The United States spends 300 times more per capita on a cold chain than India. “
Peru is one of many countries that have ordered the Pfizer vaccine. In the capital, Lima, where large amounts can be applied quickly, this must be effective, says Dr. Herman Malaga, one of a team working on vaccination opportunities in Peru. But while Lima probably has 30 ultra-cold freezers, “for the remaining 20 million Peruvians, including in the Andes and rainforests, there are none.”
“For the rest of the country, we could use vaccines like the Chinese, which require 2 to 8 degrees, which is easier to manage,” Malaga said.
“It’s about profitability, which applies not only to the vaccine, but also to the whole vaccination process,” Yadav said. But if the Pfizer candidate proves to be the most effective, the demand for ultra-cold freezers will be huge.
Barbosa says the Pan American Health Organization is urging member states not to spend huge sums on preparing for a vaccine, but to join a multilateral facility called COVAX, essentially a vaccine clearing house run by the World Health Organization.
There are other logistical obstacles beyond the cold chain.
Massive air transport will be needed to get vaccines where they need to be. Pfizer, which has production lines in Europe and the United States, says it expects an average of 20 daily freight flights around the world.
DHL expects that 15 million refrigerated boxes will have to be delivered in 15,000 flights over the next two years. David Golberg told CNN that the company has created a high-quality network of cold chains and is adding flights between China, Europe and the United States.
Many countries can use existing programs as models. Peru’s national vaccination program reaches about 75% of its population, Malaga said.
The polio vaccination program in India is ubiquitous, covering more than 90% of children this year, according to Gagandeep Kang of the Wellcome Trust’s research laboratory at Christian Medical College in Velor.
“We use boats and mules and enterprising health personnel for polio programs,” Kang said. But such programs are targeted at less than a tenth of the population, and Covid-19 vaccines will need to focus on different groups, she said.
India will need “a series of waves, each addressing a different group when the vaccine becomes available,” she told CNN.
“We will need to see the performance of other vaccines and the requirements for their delivery before calling what to do,” said Kang, who is also a member of the World Health Organization’s Global Vaccine Safety Advisory Committee.
In such a dynamic situation, record keeping becomes critical. Dr Anna Blackney, who is working on the vaccine being developed by Imperial College London, said there was no centralized infrastructure in the United States to monitor who gets what and when, which she described as a “really critical issue”.
Yadav says that even when the vaccine reaches its destination, there will need to be some flexibility to allow people to get their second dose elsewhere if they wish. And this requires reliable databases.
Barbosa said beyond the supply chain, governments “need to have a good communication strategy to overcome public skepticism and conspiracy theories about vaccines.”
Blekni agrees. “This process [of vaccine development] has been so fast that it’s no surprise that people are skeptical as they read about safety and possible side effects, “she said. Blackie is part of an international effort launched by researchers to reassure people through social media about safety and efficacy. of COVID -19 vaccines.
Finding enough dry ice is just one in a series of challenges to vaccinate the world against Covid-19.
CNN’s Claudia Rebaza and Fred Plaitgen contributed to this report.