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COVID-19 :
Vaccines are meant to elicit an immune response to an external agent without allowing it to cause disease. Historically, attenuated or inactivated viruses have been used, but Pfizer and Moderna’s proprietary COVID-19 vaccines use messenger RNA. so that the cells produce copies of the SARS-CoV-2 protein S and these are recognized by the immune system, preventing the pathogen from entering when we are exposed to the infection, as explained by El País.
Once copies of protein S are made, lymphocytes are able to kill infected cells or generate antibodies against them. Ugur Sahin, the founding physician of BioNTech, a company that together with Pfizer developed a drug using this technology, has already attempted to create a cancer vaccine in 2017 using this system.
Approval of these vaccines may represent a revolution in the treatment of other diseases. For starters, it is safer not to introduce external agents, since it is not possible for RNA-based vaccines to integrate into DNA, which could cause a certain mutation. Furthermore, the production of vaccines that use messenger RNA is cheaper.
However, Being a new type of vaccine, some questions arise, such as the duration of immunity. A researcher at the Clinico de Barcelona hospital, Felipe García, assures this “If they protect for two or three years, this would allow us to control the pandemic.” One of the last questions to be answered will be the duration of immunity.
What is RNA and where does it come from?
RNA is such an old molecule that there are theories that blame it for the beginning of life on Earth about 3 billion years ago. RNA allows genetic information in DNA to be carried out of the nucleus and, there, to make proteins. While DNA stores this genetic information using a combination of four letters (G, A, T, and C), RNA transcribes its information using four other letters (G, A, C, and U).
There are several types of RNA: messenger, which is what carries genetic information outside the cell nucleus; of transfer, which allows the assembly of proteins; Yup ribosomal, which produces the places where proteins are created.
In the specific case of SARS-CoV-2, ribosomes decode the messenger RNA injected into vaccines and create proteins that mimic the viral peak, which is a specific peak-shaped protein capable of introducing the virus into cells. Once produced, the immune system would be able to create a response against them and remember them as long as the vaccine provides immunity.
The problem with RNA is its easy disintegration. The body has proteins that are responsible for removing foreign RNAs. This explains the need to keep these drugs at minimum temperatures to prevent the vaccine from losing its effect.
Preservation
The need to keep vaccines at low temperatures poses a challenge in product distribution. In fact, Moderna made sure that its vaccine was able to maintain its effectiveness if stored for a month in the refrigerator. For its part, Curevac, whose vaccine, already acquired by the European Union, is in the final phase of testing, has extended this period to three months. Sahin, faced with widespread concern over the need to keep Pfizer vaccine at around -80 degrees, acknowledged BioNTech is working so that its vaccine can be stored at room temperature.
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