But despite great strides in equipping developing countries to maintain the vaccine “cold chain,” nearly 3 billion of the world's 7.8 billion people live in places with insufficient temperature-controlled storage for an immunization campaign to bring COVID-19 under control.
A tiny medical clinic outside Burkina Faso's capital that went nearly a year without a working refrigerator is a microcosm of how the cold chain can break.
The clinic in Gampela couldn't keep vaccines on site once its refrigerator broke last fall, nurse Julienne Zoungrana said. Staff members use motorcycles to fetch vials from a hospital in the capital, Ouagadougo, and must make a second trip to return unused doses.
When Adama Tapsoba, 24, needs to take her baby for routine immunizations, she walks four hours to reach the clinic and often waits hours for a doctor. The mother of two thinks it will be difficult for her family to get coronavirus vaccines.
“People will have to wait at the hospital, and they might leave without getting it," she said.
To uphold the cold chain in developing nations, international organizations have overseen the installation of tens of thousands of solar-powered vaccine refrigerators. Keeping temperature-sensitive vaccines safe from beginning to end also requires reliable electricity, sound roads and planning.
For poor countries like Burkina Faso, the best chance for receiving supplies of a coronavirus vaccine is through the Covax initiative, led by the World Health Organization and the Gavi vaccine alliance. The goal of Covax is to place orders for multiple promising candidates with the aim of distributing successful ones equitably.
The U.N.'s children's agency, UNICEF, began laying the groundwork for global distribution months ago in Copenhagen. At the world’s largest humanitarian aid warehouse, logistics staff try to foresee shortages in part by learning from the past, especially the spring chaos surrounding masks and other protective gear that were commandeered off airport tarmacs or stolen for black-market trade.
Cracks in the cold chain start once a vaccine leaves the factory. Cargo ships are too slow for vaccines with a limited shelf life. Carrying vaccines by air at cold temperatures costs a lot more, and air cargo traffic is only now rebounding from pandemic-related border closures.
German logistics company DHL, which has expanded its cold storage capacity in response to the pandemic, estimated that 15,000 cargo flights would be required to fully vaccinate the world against the coronavirus.
For every gap in the cold chain “we need to find a bridge,” DHL chief commercial officer Katja Busch said.
Coronavirus vaccines will be one of the world’s most sought-after products, so theft is also a danger.
“They can’t be left on a tarmac and fought over because they would actually be spoiled and they would have no value — or worse still, people would still be trying to distribute them,” said Glyn Hughes, the global head of cargo for the International Air Transport Association.
“If people can figure out how to transport ice cream, they can transport vaccines,” Dai said.
Multi-dose vials, which are the equivalent of bulk storage for vaccines, reduce manufacturing and transportation costs. But if too few people show up for their jab in time, whatever remains in the vials must be discarded.
For now, UNICEF is betting on 20-dose vials and hoping that the amount wasted will stay below 15% for opened ones, according to Michelle Siedel, one of the agency's cold chain experts.
UNICEF also expects to have 520 million syringes pre-positioned and maps of where refrigeration needs are greatest by year-end, “to ensure that these supplies arrive in countries by the time the vaccines do,” Executive Director Henrietta Fore said.
If Burkina Faso were given 1 million doses of a coronavirus vaccine today, the country wouldn’t be able to handle it, Jean-Claude Mubalama, UNICEF’s head of health and nutrition for the West African country.
“If we had to vaccinate against the coronavirus now, at this moment, it would be impossible,” he said.
Hinnant contributed from Paris, along with Aniruddha Ghosal in Delhi; Christine Armario in Bogota, Colombia; and Linda A. Johnson in Fairless Hills, Pennsylvania.