A person vaccinated against the coronavirus, illustration -
Claudio Furlan / AP / SIPA
This Thursday, the European Commission announced the possibility of perhaps marketing the Moderna and Pfizer / BioNTech vaccines from mid-December, ie in three weeks.
A delay that may seem rapid at first.
However, two experts assure him, the delay seems tenable without an overview of health and safety checks.
The European Commission said on Thursday that it could possibly give the green light in December to the Moderna and Pfizer / BioNTech coronavirus vaccines, both of which have shown greater than 90% effectiveness in the results of interim studies published in recent years. weeks.
A deadline that appears at first glance very short and very close.
To the point of raising fears of wishful thinking more than a real prospect of a date, or even worse, a vaccine whose certain security processes were urgently overlooked.
In reality, far from all that, reassures Antoine Flahault, epidemiologist and director of the Institute of Global Health at the Faculty of Medicine of the University of Geneva.
Insofar as the studies are soon to be finalized, the deadlines seem tenable.
Acceleration of production, but safeguarded safety
Eric Billy, researcher in immuno-oncology in Strasbourg and member of the collective On the side of science, specifies: “What makes commercialization possible so early is that large-scale production and pre-sales of the vaccine were launched at moment of phase 2 / phase 3, faced with the emergency, whereas normally we no longer wait for final validation.
There were therefore compromises on production, all the procedures were launched at the same time at the risk of making vaccine stocks ultimately ineffective, but there was no compromise with regard to safety tests.
Safety is defined by the study of undesirable effects during clinical phases 2 and 3. "
Once the final study is published, two months after the second vaccination which serves as a booster, to ensure that there is no problematic negative effect, the results are given to the various agencies, in particular the European Medicines Agency (EMEA).
Moreover, for Antoine Flahault, "if the European Commission is so optimistic, it is because the EMEA must have had guarantees to receive the files extremely quickly".
Eric Billy believes that this famous file “should arrive in the coming days for Pfizer and Moderna, and in December for AstraZeneca.
"
Expertise and meeting in three weeks
Once this file is in hand, what remains to be done?
The agency is carrying out an assessment by a team of volunteer expert researchers, "experts who in view of the emergency will clearly free up all their time available for this," said Antoine Flahault.
Their role is to verify the calculations and data in the report, which takes around one to two weeks.
The agency can also hear from the manufacturer if it has questions or points of the report to be raised by the experts.
These two devices "are necessary, will have priority but cannot be compressed or hovered over, and this will not be the case," assures the epidemiologist.
From there, the Commission meets to give an opinion, a process that takes no more than a day or two, even hearing the lab at the same time.
"It often happens that there is consensus, but debates and votes are not to be excluded", supports Antoine Flahault.
So a total of three weeks, so ready for mid-December.
The account is good.
Very long term risk?
Yes, but despite this delay of two months of studies after the vaccination booster, isn't it a bit short to be absolutely certain of having no side effects in the longer term?
First element, it is a rather normal delay according to Eric Billy: "Two months of delay after the reminder of vaccination, it is not an excessive speed, it is more or less the norm, and we cannot speak of security rule relaxed in a hurry.
"
This does not exclude the risk of a very long term effect.
But as Antoine Flahault says, “it is a risk specific to any new medical product, whether it was made in an absolute health emergency or not.
Understand that no new drug takes years and years to be marketed to absolutely guarantee the lack of long-term effect.
The epidemiologist continues: “We just wait and observe what happens once he's out.
"
He takes the example of a dengue vaccine recently released by Sanofi, with extremely promising clinical tests, but which has proved to be more or less harmful depending on the type of population vaccinated.
In fact, now it is only attributed to a certain type of population.
“Some things and effects can only be discovered with use,” continues Antoine Flahault.
In view of the doses of vaccine announced at the moment, the people concerned by the vaccination, namely the elderly, "should not be too concerned by the too long-term effects.
This is a question that will arise in the longer term ”.
The case of recontamination
Another point and reason for uncertainty raised by Eric Billy, what effect will the vaccine have on a person who has already contracted the coronavirus without knowing it, therefore the asymptomatic or little symptomatic forms?
“There could be a hyperinflammatory risk that could arise as a result of an excessive humoral immune response, a fairly rare case.
"In their press release, Pzifer assures" that patients who have already been infected have also been vaccinated successfully and without specific side effects.
"
But here too, given the few doses at the start, "it will only be necessary to vaccinate the oldest and most fragile cases, which have few asymptomatic cases", he notes.
He insisted on "the very good news" that these phase 3 studies constitute: "We are now awaiting the final publications.
As in a marathon, it is the last few meters that appear to be the longest.
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