The new health guidelines imposed by the government have resulted in a record number of appointments being made to receive a dose of vaccine.
But for some, it is more the fear of seeing their wasted that motivated this decision rather than a real confidence in the various vaccines administered.
If there are, of course, opponents of the vaccine who firmly reject the idea of receiving the serum, several French people are simply worried: "We do not have enough hindsight", "we do not know enough about possible side effects ”, we hear regularly, in particular because of the messenger RNA technology used for these vaccines.
We take stock.
Messenger RNA is not that new
First of all, it is necessary to define what this technology is that we have heard about since the beginning of research on the vaccination against Covid-19. Normally, a vaccine involves injecting the body with an inactive or attenuated version of the infectious agent in order to generate antibodies which will then allow us to defend ourselves in the event of contact with the disease. In the case of Messenger RNA, DNA fragments are introduced whose mission is to send a message to the cells which will then develop a protein allowing us to protect us against a Covid-19 infection. This method, certainly unprecedented, is nevertheless perfected since it has been studied for almost ... 30 years.
While the average search time for the best immune response to a disease is around 5 to 10 years, Messenger RNA technology can save a lot of time because these vaccines are easier to produce. “It's much more difficult to take a virus, to work on it, to mitigate it. There we don't need to do all that so it saves several years and I think it's even safer than when we inject a virus, ”explains Franck Mennechet, researcher in immunology, vaccination and virology. These messenger RNA vaccines have also already been tested against the Ebola and Zika viruses. It is therefore impossible to say that we have "no hindsight" on this technology. On the other hand,These Messenger RNA vaccines had never been used on a planetary scale to deal with a pandemic, which can legitimately give rise to doubts or fears.
Immediate "usual" side effects
Again, there are many concerns that need to be brushed aside. It should be noted from the outset that the vaccines have indeed been approved after clinical trials, certainly faster than usual, but on a gigantic volume of people. Then, it is necessary to distinguish two different temporalities concerning the undesirable effects of a vaccine. First of all, there are the immediate effects which may occur immediately after receiving the serum and then there are those which may appear several years later. In the first case, some inconvenience has indeed been noted. Headache, pain in the arm, some nausea, a slight fever but a very small number of serious reactions, such as thrombosis. "There is a difference between a bad reaction to the vaccine and severe side effects", explained to the Parisian,immunologist Claude Leclerc.
Also questioned in our columns, Nathan Peiffer-Smadja, infectious disease doctor at Bichat hospital (Paris XVIIIth) affirmed that these immediate side effects were "usual with vaccines" before adding: "What we know about the main products against the Covid-19, it is that there is no very serious side effect which appears for the moment ”.
And here again, sufficient hindsight exists because according to the scientific community, only a few months are enough to detect short-term side effects.
Preventing possible long-term side effects: the objective of "pharmacovigilance".
Regarding the long-term consequences, it is quite unlikely that we will witness a wave of serious side effects in the next few years, according to Alain Fischer, chairman of the advisory board of the vaccine strategy and professor of pediatric immunology.
"In the history of vaccination, the rare and very rare serious side effects that have been observed have been observed in the days or weeks following vaccination, there is no notion of long-term complication. vaccination for the type of vaccine used for Sars-COV-2, ”he explained to the Parisian a month ago.
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In all cases, RNA vaccines must henceforth undergo a phase of “pharmaco-surveillance” or “phase 4”, the objective of which is to closely observe the behavior of subjects who have received the vaccine. “This phase aims to intervene immediately if ever we spot a problem in certain people. », Explains Franck Mennechet. Therefore, it is obvious that there is no going back over a period of 40 or 50 years. “But it's the same as soon as a new drug hits the market. There is never any immediate hindsight over half a century, ”he adds.