Vaccine Cold Chain Logistics Challenges: How to Save Life with a Chemical “Casing”

Looking for a vaccine in the face of an unexpected outbreak and a second wave Against COVID-19.. The reason for this is simple: the vaccine works. They save lives and the economy.

For example, 11.6 million smallpox cases Reported and estimated between 1920 and 1978 300 million deaths From illness. But in 1979 the World Health Organization Declared smallpox It has been completely eradicated thanks to strict vaccination programs around the world.

One of the key elements of this success is that the smallpox vaccine is a “thermostable” vaccine. This means it can be stored and transported without refrigeration, making it widely accessible and transportable around the world.

Unfortunately, thermal stability Not a property For most vaccines, including those against diphtheria, tetanus, whooping cough (DTP), measles, mumps, and rubella (MMR). But our New research Has taken an important step in storing such medicines without the need for expensive (and sometimes unreliable) refrigeration.

Vaccines are usually not heat stable, and vaccines that are not properly refrigerated will ruin quickly because they contain biological substances that degrade unless stored at 2°C to 8°C. As a result, the vast majority of vaccines rely on refrigeration or “cold chain” distribution, which consists of several stages.

First, vaccines are manufactured by manufacturers who store them in a controlled refrigerated environment. Second, all modes of transport and storage (chains) need to be cooled to ensure that the vaccine remains active until it reaches the patient. This means everything from lorries and planes to warehouses.

There are some things that can fail during this process. This requires a high level of consistency and maintenance. Some research Indicated Up to 50% of vaccines distributed to low-income countries are wasted.

Even in the wealthiest parts of the world, poor equipment and handling can degrade vaccines and lead to very expensive waste. There is an urgent need for new technologies that can prevent this.

our the study We have developed a new method called “precipitation” using the natural compound silica (SiO2), which is the main component of sand. Since silica is cheap, abundant and easy to use, it uses a soluble form to encapsulate the vaccine component at the molecular level. This is like creating a small individual cage for each virus or protein that mimics its shape, preventing the protein from “unfolding”.

When a protein develops, it loses its function and decomposes, making it unusable as a vaccine. This is very similar to how a properly crafted paper plane glides in the air only when the paper is properly folded into a particular shape. As soon as you fold it back, it won’t fly.

For proteins, heating and cooling can change their shape. Our method helps prevent the proteins that are components of the vaccine from deteriorating from too hot or too cold temperatures.

Sand for safety

In our study, silica grows chemical reactions in solution as a branched network (called a polymer), which matches the structure of vaccine proteins at the nanoscale. These encapsulated proteins are then collected as a dry powder that can be safely stored and reconstituted before use.

our Recently announced works Show the ability of the method of the invention to preserve tetanus protein fragments used in diphtheria, tetanus, pertussis (DTP) vaccines. Vaccines work by mimicking natural infections that then provide lasting immunity.

To show that our method preserved this protein, we stress-tested it by heating it to 80 °C. The silica was then stripped and the protein tested for an immune response compared to a control non-silicated protein stored in the refrigerator.

No difference was seen between control and sample. This shows that our method can store proteins without the need for freezing. This is a great achievement. Additional control of the design confirmed success.

Hope, and the focus of continued research, is that our method allows for wide distribution of non-refrigerated vaccines. This helps people at distant destinations to be vaccinated. It also enables long-term storage of vaccines and stockpiles, helping to prepare for the rapid outbreak of new diseases.

Vaccines make a huge difference in global health and save millions of lives. However, a heat-stable vaccine is needed to ensure that everyone is protected. Several technologies, including us, aim to address this issue. Once COVID-19 vaccine, Distribution is top priority.

About the author

Asel Sartobayeva, Chemistry instructor, Bath University And Aswin Dohier,doctor student, Bath University.. Asel Sartbaeva received funding from the Royal Society, Royal Society of Chemistry, Annette Trust, British Council and EPSRC. Aswin Doekhie was funded by Annette Trust and the British Council of Bath.

This article is courtesy conversation..