The Conversation Spain
Covid-19 vaccines: The cold supply chain does not reach everywhere, preventing its equitable administration
Bringing vaccines to rural and hard-to-reach areas is essential for ethical and public health reasons. Hector Roqueta Rivero / Moment via . To serve as an instrument for reducing health inequalities and promoting social justice, coronavirus vaccines must also be distributed among populations that have fewer services and among those communities that are difficult to access. While there aren’t too many places in the United States that can’t be reached by road, there are other challenging circumstances. Thus, for example, many hospitals in rural areas have an unstable power supply, or cannot afford freezers that cool to extremely low temperatures. However, if there is will on the part of the Government and the necessary resources are allocated, these difficulties can be overcome. But this is not the case in most countries in the rest of the world. One of our team members, Tim Ford, is a global health researcher and has conducted a large number of international studies on water and sanitation in places where supply chains do not reach. His last destination has been various rural areas of Haiti. Another member of our group, Charles Schweik, focuses his research on the ways in which the spread of innovations (both digital and material) can help solve inequalities and pressing social problems. The Pfizer and Moderna vaccines are a great starting point, and we should celebrate. But its effectiveness requires a “cold chain,” that is, a complex supply chain that involves freezers and transportation methods that integrate temperature control. This need to preserve the cold chain (and the fact that in many parts of the world this is impossible) has raised a series of concerns regarding the fairness and justice of vaccine delivery. There are researchers who are working hard to develop vaccines that do not need the logistical and economic nightmare that means that distribution has to respect a cold chain. Less developed places (such as certain areas of Haiti) lack the necessary infrastructure to store or transport vaccines without breaking the cold chain. AP Photo / Rodrigo Abd Where the cold chain does not reach In poor regions, in the most remote areas of the world or in those places where the average temperature during the day is very high and there is no access to electricity (or this access is very deficient), evidently the necessary conditions to keep the vaccines at low temperatures are not in place. In these places, in fact, there may not even be roads (and let’s not talk about airports). And even where there are roads, they may be impractical during certain times of the year, or inaccessible for political reasons or armed instability. But both Moderna’s and Pfizer’s vaccines must remain frozen, and the cold chain must be preserved for transport. Only the richest countries have the resources to implement a strong cold chain, and this means that large swaths of the world’s population will not have a vaccine against COVID-19. This is bad in terms of public health, and it is also unfair and unfair. Dryvax, the lyophilized smallpox vaccine, was the first temperature-stable vaccine. James Gathany / CDC via Wikimedia Commons Room temperature vaccines Vaccines that are being developed do not require such low storage temperatures. Some companies, including AstraZeneca and Johnson & Johnson, are developing vaccines that only require conventional refrigeration and not freezing temperatures. At the end of December, the United Kingdom authorized the use of the AstraZeneca vaccine, and both this and Johnson & Johnson’s should reach the world market in the next two months and thus greatly expand the number of people who can be vaccinated. The two companies are also collaborating with the COVAX Facility, which defines itself as “a global mechanism for mutualisation of risks for the joint acquisition and equitable distribution of the next vaccines against COVID-19”. The goal is to make the vaccine available to all countries participating in the COVAX program, regardless of their income level. By mid-December, 92 low- and lower-middle-income countries had signed up to the program. Conventional refrigeration is an advance over freezer storage, but ideally, for more remote regions, vaccines could be stored at room temperature. For this reason, there are researchers who are working on the development of thermoregulable vaccines that do not need refrigeration. Techniques that eliminate vaccine dependence on cold chains have been used successfully for decades. Freeze-dried vaccines are one example, but the first thermoregulated vaccine was developed in 1955 against smallpox, and it owes part of the credit for eradicating this disease. Today, researchers continue to search for innovative methods to stabilize vaccines against viruses, from drying them by contact with the air thanks to low-cost sugar films to drying them with different stabilizing agents. Some researchers are also working on stable liquid formulas, especially with certain strains of live attenuated influenza viruses, thereby avoiding the costly air drying process, which is not always possible for low- and middle-income countries. low. All of these techniques could be applied to attenuated virus-based vaccines, such as the flu vaccine or the coronavirus vaccines being developed by AstraZeneca and Johnson & Johnson. Hope for COVID-19 Vaccines? At the moment, this is all largely basic research, but progress in this field would go a long way toward meeting global health needs. To date, the most promising efforts to develop room temperature COVID-19 vaccines come from China and India. A group of Chinese scientists has developed a method to wrap a messenger RNA vaccine in lipid nanoparticles that keep it refrigerated at room temperature. Another group of Indian scientists is developing a protein fragment that withstands high temperatures. And more recently, a group of UK researchers has begun collaborating on the development of a needle-free, solid-dose, stabilizing polymer-based vaccine. Given the limitations imposed by the cold chain, there are a number of moral, ethical and public health obligations that require investment in vaccines that can be more easily distributed. For the inhabitants of many places, this represents their only hope of being vaccinated.This article was originally published in The Conversation. Read the original. The signatories are not salaried, or consultants, nor do they own shares, nor do they receive financing from any company or organization that can obtain benefit from this article, and they have declared that they lack relevant links beyond the academic position mentioned above.