One of the biggest challenges to delivering a promising coronavirus vaccine based on unprecedented technology to millions around the world just got easier.
When Pfizer Inc. announced effective preliminary results for its vaccine candidate last week, the downside was that it must be stored at ultra-cold temperatures, posing significant logistical issues. But Moderna Inc. on Monday one-upped its rival, offering a vaccine based on the same technology that appears to be equally effective, but which also can be stored at regular refrigerated temperatures for up to a month.
The difference is significant. Delivering normal vaccines to populations in the remotest regions from India to Africa is difficult enough just on supply and transport issues. The temperature factor introduces a more daunting hurdle, requiring countries to build storage and transportation networks that can maintain temperatures far colder than that required for frozen meat. The massive investment and coordination needed raised the likelihood that only rich nations would be guaranteed access.
“The Moderna vaccine is a much more viable option for low- and middle-income countries than the Pfizer vaccine,” said Rachel Silverman, a Washington-based policy fellow at the Center for Global Development. “Cold-storage needs are less extreme.”
Not only can Moderna’s vaccine remain stable in the fridge for 30 days, it can also be kept in ordinary freezers for long-term use. Pfizer’s vaccine has to be kept at negative 70 degrees and could only be refrigerated for up to five days — at least until its researchers are able to match Moderna’s breakthrough.
“The Moderna vaccine can be accommodated within the existing vaccine distribution networks,” said Ayfer Ali, an assistant professor and specialist in drug research at Warwick Business School in the U.K. “Even in remote and underdeveloped areas, fridges are available or can be supplied cheaply.”
Although Moderna has only cut deals with a handful of developed countries for its vaccine, it received funding from the nonprofit Coalition for Epidemic Preparedness Innovations and may therefore be bound to help enable access in low-middle income countries, said Silverman.
The Boston-based biotech company’s vaccine uses the same new and experimental messenger RNA mechanism as Pfizer’s. The emergence of two promising candidates is helping ease concerns that a single vaccine won’t be nearly enough to meet global demand.
“We will need to use all of the capacity that we have and all of the vaccines that are effective as they come online,” Ali said.
Pfizer could also make its vaccine more viable by reformulating it — possibly to a freeze-dried form — to avoid the refrigeration issue, said Gillies O’Bryan-Tear, chair of policy and communications at the Faculty of Pharmaceutical Medicine in the U.K.
Meanwhile, hundreds of Covid-19 vaccines are in the pipeline, and it’s possible that another, more cost-effective candidate will emerge that uses proven technology and is easier to manufacture and ship, experts said.
“I think it will become clear in the next couple of months, there are other vaccines that are in the pipeline that are in Phase III,” said Saad Omer, director of the Yale Institute for Global Health. “There will be decisions about costs of waiting versus acting. Some might decide to wait based on broader characteristics and the need for ultra-cold chain, I think that will be a big calculation.”
Other vaccine options may be essential, as not many existing drugmakers have production facilities for messenger RNA technology.
Adar Poonawalla, chief executive officer of the Serum Institute of India Ltd. — the world’s largest vaccine producer by volume — said he had no plans “to dabble with any messenger RNA candidates” for at least 2.5 years when a new facility the company is building has been completed.
“This kind of innovation is great for the long term,” Poonawalla said in an interview. But it remains a question how many of them are going to be “useable” in a practical sense, he said.