The low temperatures necessary to maintain the doses in conditions is an issue to be resolved by logistics, especially in rural areas and less developed countries.
November 11, 2020 Share on FacebookShare Share on TwitterTweet Share on WhatsAppShare
After Pfizer's hopeful announcement about the efficacy of its coronavirus vaccine, questions have arisen around the challenges of its eventual large-scale distribution.
The vaccine is based on an innovative technology , which consists of injecting into the body genetic instructions called messenger RNA, which tell cells what to make to fight the coronavirus. It is the same method used by the American firm Moderna , also in the race to find a vaccine. But these vaccines must be stored at a very low temperature, at -70 ºC in the case of Pfizer / BioNTech's, which can represent a major logistical brake for their worldwide distribution .
“It is a problem,” said Bruno Pitard, director of research at the French National Center for Scientific Research, for whom this mode of conservation is necessary since “RNA is a very fragile molecule.”
Like Moderna's formula, the Pfizer dose needs to be dispensed at super freezing temperatures (AP)
BioNTech clarified Tuesday that once the vaccine is removed from the special freezers, the doses can be stored for 5 days in a classic refrigerator, between 2 and 8 ºC. This will make it necessary for logistics to minimize the margin of error to ensure that the material arrives at the right time and does not remain stored for too long in insufficient conditions.
For their part, all countries that buy this type of vaccine will have to fine-tune (or build from scratch) their deep-freeze production, storage and transport networks . Even for rich countries that have reserved doses, including Japan, the US and the UK, delivering the Pfizer vaccine will pose significant hurdles whenever trucks break down, power goes out, essential workers get sick and ice breaks. melt.
Thus, much of the work will fall on companies that do not belong to the medical or pharmaceutical industries . Major US courier companies, including UPS and FedEx, already have networks of freezers that they use to ship perishable food and medical supplies.
UPS is building a so-called freezer farm in Louisville, Kentucky, that company's largest distribution center, where it can store millions of doses in freezing temperatures.
“The extremely cold temperature requirement is likely to cause many vaccines to deteriorate,” warns Michael Kinch, a vaccine specialist at Washington University in St. Louis.
“It is expensive to produce, its component is unstable, it also requires cold chain transport, and has a short shelf life,” said Ding Sheng, director of the Beijing-based Global Health Drug Discovery Institute, which has received funding from the Bill Foundation. & Melinda Gates.
Another issue that keeps health authorities alert is the need for massive training of paramedics to administer the two doses , especially in rural areas where the state has less presence.
Linked to this, there is a worrying drawback. In India, for example, there have been vaccination campaigns for other diseases where many patients never showed up for the second injection , putting the immunization process at risk. With the severity of the pandemic, the scope of the measures and the presence of the issue in the media, it is expected that the return for the second dose will be greater, but it remains a topic of attention.
For this reason, the Johnson & Johnson vaccine (also in phase 3) has been noted for requiring only one dose. In turn, the formula that is being developed by AstraZeneca and the University of Oxford, must be kept cold, but not frozen. Experts had already indicated the need for more than one vaccine to present successful results and, based on different requirements, governments could use different vaccines according to each region and local capacities .
Returning to the subject of temperature, Pfizer has designed a special box to transport your long-awaited vaccine . These devices may hold a couple hundred glass vials, with ten to twenty doses of the vaccine in each. The boxes are equipped with GPS temperature sensors that will allow Pfizer to know where the boxes are located and how cold they are. If it is not low enough, workers can add dry ice.
A FedEx employee adds dry ice to a box similar to those that would be used to distribute vaccines
The resulting price may be too high for many developing countries, including India, which has struggled to contain the world's second-largest coronavirus outbreak and currently has no agreement to purchase the Pfizer vaccine.
The pharmaceutical company already has orders from some developing countries such as Peru, Ecuador and Costa Rica. It is not clear how widely those countries plan to distribute the injections, but their small orders of less than 10 million doses suggest limited deployment.
“We are just beginning to understand the complications of handover,” Stephen Morrison, senior vice president of the Center for Strategic and International Studies, a research body, said in September. “And there is no turning of the page. The temperature requirements are very specific and that will limit access and delivery ”.
(With information from AFP, Bloomberg and New York Times)