Before receiving your third dose of vaccine against Covid-19, perhaps you have thought of carrying out a dosage of your antibodies, to know where you are at in terms of your immune defenses against this coronavirus, several months after your two first injections.
You are free to ask your doctor for a prescription to perform this dosage. “But this sampling is not indicated in practice among the general population. The current health strategy is indeed aimed at immunization with the most comprehensive vaccine possible, associated with the maintenance of barrier gestures to curb the spread of SARS-CoV-2 as much as possible.
For those who have not been vaccinated in 2021, but who plan to take the plunge in 2022, what could serology be used for? “To see if they have contracted Covid-19 since March 2020.” A point which could be interesting to know your serological status, in particular “for asymptomatic forms, in patients who would therefore have missed their Covid”. But to date, this reflex would not be convincing. “Nothing certifies that antibodies that appeared in 2020 or early 2021 are still detectable during serology carried out from January 2022.”
Too person-dependent immunity
“This automatic recourse to serology does not currently seem relevant”, confirms Chantale Pichon. “Our Covid-19 immunity is too dependent. ” That is to say ? “The amount of antibodies detected after being sick or after the vaccine, as well as their maintenance over time, differs between individuals. “There is no consensus today on a threshold value to confirm that such an antibody dosage makes it possible to be effectively protected against a severe form of Covid-19. Nor to estimate how much we are protected from the risk of contamination in the event of exposure to SARS-CoV-2.
In case of long Covid
“In hospitals, on the other hand, for cases of long Covid, it is interesting to measure the antibodies to make the link between the symptomatic state of a patient over the months following the contraction of the disease and the detection of a reaction. immune system,” underlines Chantal Pichon. Especially for the mild or even asymptomatic forms which would not have been the subject of a diagnostic test. “Indeed, there are many long Covids after completely benign forms of Covid-19”, concludes Chantale Pichon.