The “cold chain” is just one of the challenges in the distribution of vaccines worldwide.
There are many others: decisions on priority populations and databases to keep track of who received which vaccine, where and when. In addition, different vaccines may have more or less efficacy with different population groups; and governments need public relations campaigns to convince people that vaccines are safe.
But the logistics of transporting and storing vaccines – getting them from the factory gate to the patient’s arm – are critical. And since most vaccines are likely to require two doses, the entire chain requirement must be repeated within a few weeks.
The Pfizer BioNTech vaccine should be kept at approx. -70 degrees Celsius (-94 degrees Fahrenheit) while being transported. It is 50 degrees colder than any other vaccine currently in use.
Moderna says its vaccine can be stored in freezers typically found in pharmacies and in refrigerators for 30 days. However, there are likely to be fewer doses of the Moderna vaccine than of Pfizers available over the next year.
Phase 3 trials have shown that both vaccines are around 95% effective, but the results have not yet been reviewed by regulators.
On Wednesday, the CEO of BioNTech, the German biotech company working with Pfizer, acknowledged the issue of temperature control.
“We are working on formulation that could allow us to send the vaccine, perhaps even at room temperature,” Ugur Sahin told CNN. “We believe that by the second half of 2021 we will have come up with a formulation comparable to any other type of vaccine.”
But in the meantime, U.S. Health and Human Services Secretary Alex Azar believes the Moderna candidate is “more flexible” to options as a local pharmacist. Pfizers, he said Monday, would be better suited for “large institutional vaccination, say an entire hospital setting, multiple nursing homes at once.”
Pfizer plans to ship up to 1.3 billion doses next year, requiring a lot of dry ice (carbon dioxide in solid form at around -78 degrees Celsius) and a lot of isothermal boxes. The boxes can hold up to 975 vials (4,875 doses) and can be refilled with dry ice for up to 15 days of storage.
Pfizer is testing the supply chain in four US states. Its CEO, Albert Bourla, said on Wednesday that he has “zero concerns” about the requirements for the refrigeration chain.
However, shipping such a vaccine can pose major challenges. Dr. Jarbas Barbosa, assistant director of the Pan American Health Organization, told CNN that “the rural and urban areas of every country in the world are not ready to handle this vaccine today.”
“So who is prepared in the world? None.”
One problem is the availability of dry ice.
Sam Rushing, president of Florida-based Advanced Cryogenics, told CNN that there is already a regional shortage in the United States.
U.S. officials are convinced there is enough dry ice available. Paul Ostrowski, director of delivery, production and distribution for Operation Warp Speed, told CNN last week that courier UPS had promised to “deliver dry ice transhipments across America as needed.”
But Rushing warns that dry ice is not very user-friendly and can be dangerous if stored incorrectly, especially in a confined space. The Federal Aviation Administration classifies it as dangerous goods.
Peter Gerber, CEO of Lufthansa Cargo, told CNN that the need for dry ice “also clearly reduces transport capacity because if you have to load more ice, you can not load as much vaccine. And of course, the procedures must be very special to ensure that it always has this degree of coldness. “
US Courier DHL adapts distribution plans according to each vaccine’s specifications. David Goldberg, CEO of Global Forwarding US for the company, says “there is a limit to the amount of dry ice used on an aircraft – typically 500-1,000 kilos depending on a number of factors.”
Upon arrival, 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 send the frozen vials directly to the vaccination point.” It also monitors the temperature of each box sent.
Julie Swann, an expert in supply chains at North Carolina State University, says large hospital systems that often have ultra-cool freezers can play a role as distribution hubs. But not all U.S. states have them; Hawaii said last week that none of its hospitals had such freezers.
Breaking down shipments of a frozen vaccine to rural areas or small groups of key workers – without compromising their temperature – would be another headache, Swann said.
When a vaccine needs to be used within a few days, providers need to make sure they are ready. “You can not just wait to see who shows up,” Swann told CNN. “And we don’t have really good data yet that defines where and who the priority populations are.”
Prashant Yadav, a supply chain expert and senior fellow at the Center for Global Development, said: “It’s a question of how quickly we can start thinking about more packaging formats.”
Beyond the United States
If getting a frozen vaccine for tens of thousands of people in the United States is a challenge, it’s a far bigger problem for poorer countries.
Transport connections are slower and medical facilities are less equipped in developing countries. CO2 production is scarce, and the cost and dangers of sending huge amounts of dry ice are also an obstacle, says Yadav.
David Gitlin, chief executive of refrigeration specialists Carrier, told CNN last week: “Looking at places like Africa and India, they just do not have the cold chain infrastructure. The United States spends 300 times more per capita on the refrigeration chain than India.”
Peru is one of many countries that have ordered the Pfizer vaccine. In the capital Lima, where large quantities can be administered quickly, it must be effective, says Dr. Germán Málaga, one of a team working on Peru vaccination opportunities. But while there are probably 30 ultra-cold freezers in Lima “for the other 20 million Peruvians including in the Andes and the rainforest, there are none.”
“In the rest of the country, we could use vaccines like the Chinese [CoronaVac] https://edition.cnn.com/2020/11/11/health/brazil-vaccine-sinovac-trials-covid-intl/index.html that requires from 2 to 8 degrees, which is more manageable, “said Málaga.
“It’s about cost-effectiveness, which is not just about the vaccine, but the whole process of vaccination,” Yadav said. But if Pfizer’s candidate proves to be the most efficient, the demand for ultra-cold freezers would be overwhelming.
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 clearing house for the purchase of vaccines operated by the World Health Organization.
In addition to the refrigeration chain, there are other logistical obstacles.
A massive air lift is required to get vaccines where they are going. Pfizer, which has production lines in Europe and the United States, says they expect an average of 20 daily cargo flights worldwide.
DHL expects to deliver 15 million refrigerators on 15,000 aircraft over the next two years. David Golberg told CNN that the company has established a high-quality cold chain network 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 approx. 75% of the population, Málaga said.
India’s polio vaccination program is ubiquitous – covering more than 90% of children this year, according to Gagandeep Kang of the Wellcome Trust Research Laboratory at Christian Medical College in Vellore.
“For polio programs, we have used boats and mules and enterprising health professionals,” Kang said. But such programs are designed for less than a tenth of the population, and Covid-19 vaccines will have to focus on different groups, she said.
India needs “a series of waves, each targeting a different group when the vaccine becomes available,” she told CNN.
“We need to look at the performance characteristics of other vaccines and their delivery requirements before calling what to go with,” said Kang, who is also a member of the World Health Organization’s Global Advisory Committee on Vaccine Safety.
In such a dynamic situation, record keeping becomes critical. Dr. Anna Blakney, who works on a vaccine developed by Imperial College London, said there is no central infrastructure in the US for monitoring who gets what and when, which she describes as a “really critical issue.”
Yadav says that even when the vaccine reaches its destination, there must be some flexibility to allow people to get their second dose somewhere else if desired. And it requires reliable databases.
Barbosa said governments “beyond the supply chain” must have a good communication strategy to overcome public skepticism and conspiracy theories about vaccines. “
Blakney agrees. “This process [of vaccine development] has been so rapid that it is not surprising that people are skeptical as they read about safety and possible side effects, “she said. Blakney is part of an international effort initiated by researchers in the field of research to reassure people via social media about the safety and efficacy of COVID -19 vaccines.
Finding enough dry ice is just one in a series of challenges to get the world vaccinated against Covid-19.