A prick in the arm, and a prick in the finger. This is what the High Authority of Health (HAS) in its opinion in favor of carrying out a rapid serological test (or TROD) free of charge on the day of the first injection of the anti-covid vaccine.

The objective: to identify people who have already had covid without necessarily knowing it in whom a single dose of vaccine is sufficient to achieve maximum protection. The Minister of Health Olivier Véran had announced the day before on TF1 that he would follow that advice. This measure would free up “few millions“additional doses.

To read also: Vaccination: from when are we protected?

A drop of blood on the fingertip

HAS recommends testing first in a few vaccination centers whether this provision does not disrupt the organization of the vaccination campaign, “before any large-scale deployment“. But the selected centers will be equipped from June with”rapid serological tests to detect the presence of antibodies“.

It will then suffice to take a drop of blood from the fingertip of the person who wishes to be vaccinated and the result, 15 minutes later, will indicate whether they already have antibodies against SARS-CoV-2.

One dose is enough

If the test is positive, it means she has been in contact with the virus before. The appointment for the second dose may then be canceled because “the scientific data we have today are clear: one dose is enough“for people already infected in the past, explained Professor Dominique Le Guludec, president of the HAS, at a press conference.

Better, “vaccine protection of people who have been infected with the virus is better after a single dose of vaccine than that of people never infected with two doses“, assures the president of the HAS.

“Several million” doses released

“We rely a lot on TRODs to release doses“, also declared Elisabeth Bouvet, president of the technical committee on vaccinations at the HAS.
According to the health authority, “a large reservoir“of”few millions“of doses would thus be made available to accelerate the protection of the population against covid.

Many asymptomatics in young people

And for good reason: according to modeling studies of the epidemic by the Institut Pasteur, “more than 22% of people in metropolitan France have been infected with SARS-CoV-2 and more than 40% in Ile-de-France. However, the cases identified by a virological test represent only 8% of the population.“, recalls Professor Le Guludec.

Cases passed under the radar which could be numerous among the next first-time vaccinated, because “we are coming to a phase of the vaccination campaign that targets younger people“, more likely to have made an asymptomatic form of the infection gone unnoticed, she finally added.