Vaccines are intended 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 S protein of SARS-CoV-2 and these are recognized by the immune system, preventing the entry of the pathogen when we are exposed to contagion, as explained by El País.
Once copies of the S protein are created, lymphocytes are able to kill infected cells or generate antibodies against them. Ugur Sahin, the founding physician of BioNTech, a company which together with Pfizer developed a drug using this technology, already attempted to create a cancer vaccine in 2017 using this system.
The approval of these vaccines may represent a revolution in the treatment of other diseases. For starters, it is safer not to introduce external agents, as it is not possible for RNA-based vaccines to integrate into DNA, which could cause a certain mutation. In addition, the production of vaccines using messenger RNA is cheaper.
However, Being a new type of vaccine, some questions arise, such as the duration of immunity. A researcher at the Clínico de Barcelona hospital, Felipe García, assures that “If they protect for two or three years, that would allow us to control the pandemic.” One of the last questions to be answered will be the duration of the 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 the genetic information in DNA to be transported out of the nucleus and there to produce 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 of the cell nucleus; of transfer, which allows the assembly of proteins; Yes ribosomal, which manufactures 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 have the task of removing foreign RNAs. This explains the need to keep these drugs at minimum temperatures to prevent the vaccine from losing its effect.
The need to keep vaccines at low temperatures poses a challenge in product distribution. In fact, Moderna made sure that their vaccine was able to maintain its effectiveness when 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, facing widespread concern over the need to keep the Pfizer vaccine at around -80 degrees, acknowledged that BioNTech is working so that its vaccine can be stored at room temperature.