- Antonio J. Ruiz Alcaraz *
- The Conversation
The emergence of the covid-19 pandemic has had a great impact worldwide, both from a social and economic point of view, as well as from a biomedical and technical scientific point of view.
Therefore, the need to face this pandemic has promoted a great international effort. This situation has, in turn, allowed the development of an important battery of vaccines to fight against SARS-CoV-2 in record time.
However, this latest finding has raised a good number of doubts and questions about vaccines among the general population.
We present below the main doubts and questions and their corresponding answers.
“Is there a risk that the RNA from the vaccine will integrate into my genome and modify it?”
Messenger RNA o mRNA is a molecule that serves as an instruction manual for building proteins. It would be something similar to the paper that contains the steps to assemble a piece of furniture.
When we finish assembling the furniture, the manual is thrown away, it is not kept in the home library. And this is what our cells do.
The mRNA does not enter the nucleus of the cell where our genetic material is, but carries out its ephemeral function in the cytosol of the cell and there degrades.
In the case of mRNA-based vaccines, both this molecule and the fat particles in which the mRNA is “packaged” are eliminated as soon as the cell has synthesized the viral protein they encode.
The viral protein will be the one that awakens the immune system and will allow the appearance of a response and a specific memory against said protein.
Therefore, it will be effective against the virus that contains it in nature, but without us having to be infected by the pathogen that causes covid-19.
“We don’t know what the vaccine contains”
The content of the vaccines that are currently being used against covid-19, such as those for mRNA by Pfizer-BioNTech or Moderna, as well as that of all those currently used against the rest of infectious diseases is perfectly known.
Vaccines are drugs that, like the rest, have a clearly determined composition specified in their corresponding technical guidelines.
“Clinical trials are still in phase 3”
In phase 3 clinical trials, there is already enough data to solve the basic questions about a new drug, since it is in this phase that its clinical efficacy and safety.
This means that these drugs can receive the relevant authorization for marketing and use.
In the following phases, other data and long-term effects are ascertained, such as the duration of protection offered by vaccines or the effectiveness against infection. But these need studies with a larger population size and duration.
Therefore, in a pandemic situation like the current one, it is not weird that drugs are started while they are still in clinical phase 3 and while progressing to phase 4.
“The technology of mRNA vaccines is too recent”
The need to fight covid-19 has been the one that has given a strong impulse to the use of messenger RNA vaccines.
But the idea of using this material as a basis for the production of vaccines, as well as the use of lipid nanoparticles for their transport, goes back decades.
In fact, it has shown such potential that it is currently being used for the development of other promising vaccines against pathogens such as the Zika virus.
Also against other viruses for which classical vaccination strategies have not been effective, either due to their high mutation rate, as is the case of the virus of the gripe, or by its ability to evade the immune response, as is the case of VIH, the cause of AIDS.
“Time to market has been too fast”
In terms of time to market, it has indeed been shorter than usual.
But this has been because, precisely to respond to the pandemic, drug control agencies, such as the European Medicines Agency (EMA), have reviewed the results of the companies and research groups that develop the vaccines at the same time that these were appearing.
Therefore, instead of waiting, as they did until now, until the entire procedure had finished to carry out the data review, they have carried out this review in parallel.
This process has allowed greatly reduce the time required to grant authorization for the marketing and use of these vaccines.
“It is not known if the vaccines are effective in limiting the transmission of the virus”
There are reports showing that the viral RNA load in the respiratory tract of vaccinated is similar to that of unvaccinated infected.
But such data is based on the amount of genetic material of the virus detected, which does not mean that vaccinated individuals are as contagious as unvaccinated individuals.
That is, this information does not allow us to distinguish the infective capacity of the viruses present in the respiratory tract of the two groups of individuals.
It is clear that current vaccines are not designed to prevent viral infection but to avoiding the most serious symptoms of illness and death.
But there are data from researchers from different countries that show that vaccination reduces the infectious capacity of individuals immunized with these vaccines.
Thus, it is estimated that vaccinated people would show a much lower risk of transmitting the virus to other people than those who have not been vaccinated, even in the case of the Delta variant of the virus.
This reduction in the risk of virus transmission is also accompanied by a considerable lower risk of infection when the individual is vaccinated, as has been shown in a study carried out among health personnel in Spain.
In addition, recent data in the process of publication show that vaccinated people would clear the virus from their body much faster than non-vaccinated people, even when the dominant variant is delta.
In short, vaccinated people they are less contagious than those that are not.
All these clarifications and others based on scientific evidence must answer the doubts of citizens and help them understand that the vaccines developed against covid-19 are the best weapons we currently have to stop the pandemic.
And that all the data indicate that they are as safe as other classic vaccines that we have been using since the last century and that, after the purification of the water, they have meant the second largest biosanitary advance that has saved the most lives worldwide.
* Antonio J. Ruiz Alcaraz is pProfessor of Immunology at the University of Murcia and researcher at the IMIB Innate Immunity Group, University of Murcia, Spain.
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Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.