These two vaccines are not exactly intended for the same audience.

Because of an increased risk of myocarditis (an inflammation of the heart) with Moderna in people under 30 years old, Pfizer should be used as a priority in this age group.

Consequence: when both are available, those over 30 rather receive Moderna to prevent the doses of Pfizer from running out.

At the entrance to the Ploufragan vaccination center (Côtes-d'Armor), a placard sets the tone: "Over 30 years, Moderna".

A quadra warns at the reception: "Me, I do not want Moderna".

"At your age, we only have that available," Nicole replied courteously, in her royal blue and orange Civil Protection outfit.

Same fears among a few people at the Toulouse vaccinodrome.

"It stresses me. We changed my vaccine, I'm going to have Moderna," said, visibly distressed, a sixty-year-old who wishes to remain anonymous.

"Pfizer = Moderna"

Another woman in her forties comes out of the queue: "This is unacceptable. I'm going to go."

"People are moaning a little because this week we went from Pfizer to Moderna whereas, until now, we were only doing Pfizer. Sometimes there are some who are even a little aggressive. For them, Pfizer is the best, "Jeanne-Yvonne Falher, head of the Ploufragan center, told AFP.

"On Wednesday, nine people who had made an appointment left without being vaccinated when they knew that they could only have Moderna", she continues, while relativizing since her center does 900 vaccinations per day.

This week, government and scientists have come to the front to allay those fears.

"If I had to summarize, Pfizer = Moderna, with a single limit, it is the under 30s for whom Pfizer is recommended instead", insisted Thursday on France 2 the Minister of Health, Olivier Véran.

French Minister of Health Olivier Véran leaves the Elysée Palace in Paris, December 8, 2021 Bertrand GUAY AFP

"Moderna is at least as effective as Pfizer, I say at least because studies show it may even be a little more efficient," he added.

This was noted by the High Authority for Health (HAS) on November 8 by giving the green light to the use of Moderna for recalls, on the impetus of the European Medicines Agency (EMA).

The only difference with the first injections is that only half a dose of Moderna is given as a booster.

Because if the technology used is the same (messenger RNA), this vaccine is more concentrated than that of Pfizer.

Stocks

In addition, "heterologous vaccination, that is to say having once Pfizer once Moderna or vice versa, is considered more protective", argued Mr. Véran.

These persuasive efforts aim to keep pace with the recall campaign: Mr. Véran wants 20 million French people to have theirs by Christmas (against some 13 million currently).

"If we only use Pfizer, we will not have enough doses," warned Jean-François Delfraissy, president of the Scientific Council which guides the government, Wednesday in the Senate.

"We have more than 20 million doses in stock and we continue to receive each week, which will allow us to be in capacity", assured the Minister of Industry Agnès Pannier-Runacher Thursday on CNews, in promising "15 million doses" in January and as many in February.

French Minister for Industry Agnès Pannier-Runacher in Paris, November 18, 2021 Eric PIERMONT AFP / Archives

The equation is complicated, however, by the fact that vaccine availability varies between centers.

"I started with Pfizer and wanted the 3rd dose with", admits Cédric Lecourt after his injection.

Wish granted: only this vaccine is currently available in its vaccination center in Marcq-en-Baroeul (North).

© 2021 AFP