Doses of Pfizer vaccine against Covid-19 (illustration). – Bienvenido Velasco / EFE / SIPA
- In France, three vaccines are currently administered against Covid-19: those of Pfizer, Moderna and AstraZeneca, whose reputation has recently been tarnished by its temporary suspension for rare cases of thrombosis.
- According to a brief debate sequence broadcast on CNews on Monday, Pfizer’s vaccine would have undesirable effects “more important” than those “of other vaccines”.
- 20 minutes takes stock of this statement.
The AstraZeneca vaccine against the Covid-19, a time suspended then re-authorized, would it wrongly suffer from a bad reputation with the public while its alternatives, Pfizer and Moderna, would give rise to as much, if not more, of ‘side effects ?
This is what seemed to say, Monday April 12, during a debate on Cnews around vaccines, Doctor Jean-Michel Cohen: “We never tell about the side effects of the Pfizer vaccine. […] The side effects of Pfizer are more serious than the side effects of other vaccines. “And the doctor to receive, in the wake, the support of the LREM deputy Anne Genetet, according to whom these effects of the Pfizer vaccine would be” in particular [ressentir] at the second injection ”.
Sure @CNEWS in @morandiniblog doctor @JeanMichelCohen : We never tell about the side effects of the pfizer vaccine. They are more important than those of other vaccines. @AGenetet add: especially at the second injection pic.twitter.com/KQT1kSiFKh
– Mouâd Boutaour Kandil (@boutaour) April 12, 2021
FAKE OFF
“’More important’ side effects mean everything and say nothing at the same time. If, by more important, we mean “more numerous”, yes, there have been more effects reported with Pfizer’s vaccine than with others, but it was administered much more than those of Moderna and AstraZeneca. », Nuance with 20 minutes the teacher Antoine Pariente, head of the Regional Pharmacovigilance Center (CRPV) of Bordeaux, which, with the CRPV of Marseille, ensures
weekly monitoring of side effects reported from Pfizer’s vaccine.
With 13,485 cases recorded on April 1, 2021 for the latter, against 9,336 for that of AstraZeneca and 730 for that of Moderna – according to the data of the National Medicines Safety Agency (ANSM) stopped on April 1, 2021 -, Pfizer’s vaccine is indeed widely at the top of the adverse reactions identified.
But this figure remains to be put into perspective by the number of doses used since the start of the vaccination campaign: Pfizer far exceeds the other two vaccines with its more than 8,513,000 injections on April 1, 2021, against 2,454,000 for AstraZeneca and 801,000 for Moderna.
“A direct comparison between vaccines is not relevant”
“If, by” more important “, we mean” more marked adverse effects “, in truth, it is impossible to say”, continues Antoine Pariente. “A direct comparison between vaccines, with regard to serious adverse effects, is not relevant because the populations initially targeted by each one is very different: they were nursing home residents and health personnel. old for that of Pfizer, while that of AstraZeneca concerned the young health personnel ”, explains the person in charge of the CRPV of Bordeaux and director of the research team“ Pharmaco-epidemiology and evaluation of the impact of health products on populations ”at Inserm.
In his latest report, the ANSM notes that “the majority of adverse effects [du vaccin Pfizer] are expected and not serious “, that” a large number of cases [du vaccin Moderna] concerns delayed local reactions that are not serious ”while“ the vast majority of [effets indésirables d’AstraZeneca] concerns flu-like syndromes, often of high intensity (high fever, body aches, headaches). “
But the national body does not fail to note at the same time that these undesirable effects more or less affect certain categories of the population: “The reactogenicity was generally of milder intensity and reported less frequently in older adults ([plus de] 65 years). “
“The typology of risks depends on the categories of people concerned”
“RNA vaccines [de Pfizer et de Moderna] are generally very well tolerated, they have undesirable effects that we know about: access to hypertension, zonas… ”, abounds with 20 minutes Mathieu Molimard, pharmacologist and pulmonologist, member of the scientific council of the site of the French Society of Pharmacology and Therapeutics (SFPT), while emphasizing: “The typology of risks depends on the categories of people concerned: the rare cases of thrombosis, in the AstraZeneca cases, have been observed in young people, but not in the elderly. “
On his website, the ANSM, on the other hand, confirms the second point raised on CNews: “The frequency of systemic reactions, and particularly of fever, fatigue and headaches, is greater during the administration of the second dose. [du vaccin de Pfizer] compared to the first dose ”- the same as for Moderna’s vaccine.
“The effects of reactogenicity are indeed greater with the second dose of Pfizer than with the first. But are they greater with the second dose of Pfizer than with AstraZeneca, for example? We don’t know, ”concludes Antoine Pariente.