Serological tests detect the presence of antibodies produced by the body to fight against the coronavirus. At the heart of the health crisis, many laboratories have started manufacturing these screening tests. To verify their reliability, the National Reference Center (CNR) has decided to sort through the various tests.
Nearly 23 tests have been approved by the institution. In this list, the CNR validated the ELISA tests and the rapid diagnostic tests (RDTs). Regarding the ELISAs, the patients carry out a blood test in the laboratory. The blood sample is then analyzed using reagents which react to antibodies. For RDTs, the results are available after fifteen minutes. A blood sample, taken on the fingertip, is immersed in different reagents to identify the presence or absence of antibodies.
Serological tests: who can benefit from a reimbursement?
On May 20, the French National Authority for Health (HAS) declared itself in favor of reimbursing the ELISA and TDR serological tests, the reliability of which has been established by the CNR. At that date, only virological tests (PCR) were reimbursed by Health Insurance. Unlike serological tests, these tests aim to detect the virus when it is still present in the body.
In a decree, published in the Official Journal on May 27, the Ministry of Health and Solidarity gave more precise information on the reimbursement of serological tests. Several categories of individuals will therefore benefit from full reimbursement by Social Security. For people at risk of developing a severe form of Covid-19 (the elderly, those with co-morbidities), the text states "full coverage by health insurance (…) of the serological test for antibodies to the SARS-CoV-2 virus ".
Serological tests will also be reimbursed for teams working in health establishments, social or medico-social establishments. According to HAS, these screening tests must be prescribed by a doctor.
Even if antibodies are detected by a serological test, they must be in sufficient quantity to avoid re-infection of the coronavirus. Except for the moment, the necessary threshold of antibodies to guarantee immunity against the coronavirus is not yet known to scientists. "We have a trivial idea, the more neutralizing antibodies we have, the better we are protected, if we compare to a car, we know that the more powerful the engine, the faster it will go, but that doesn't give us its exact speed", explains Marc Eloit, researcher at the Institut Pasteur at HuffPost.
Read also :
⋙ Serological tests or PCR: this site tells you where you can get tested near you
PCR PCR, serological, rapid or saliva tests: what are the different screening methods for coronavirus?
⋙ Coronavirus screening: who can benefit from it and how to get tested