Covid-19: antigen tests withdrawn from the market after several cases of “false positives”

All French pharmacies received the same message on Monday, December 14: “We ask that you no longer use the VivaDiag Rapid Test SARS-CoV-2 Ag rapid test and quarantine those in your possession.“. The alert was given by the National Agency for the Safety of Medicines and Health Products (ANSM). This decision follows the obtaining of numerous false positive results with this test. “The performance of this device is not guaranteed“, specifies the ANSM press release. The organization asks health professionals to contact people who have tested positive in the last seven days, so that they can confirm the result obtained with a PCR test.

Faster testing

The test is made by the Chinese company Viva Chek. It was previously part of the antigenic tests authorized in France: the first arrived on the market in October. Today, there are about 80 available in French pharmacies. Their main advantage is their speed: it takes 30 minutes to obtain a result, compared to 24 hours for a PCR test. This different delay is linked to their functioning: the PCR test detects the presence of the virus, the antigenic test looks for the antigens produced by SARS-CoV-2.

A test intended primarily for symptomatic people

This rapid test can be performed by pharmacists, doctors, midwives, dental surgeons, or private nurses. It is less reliable than the PCR test, which is why it was initially reserved for symptomatic people aged under 65. Extended to contact cases since November, this examination consists of placing a swab in each nostril. Then, a chemical reagent makes it possible to know if the virus is present. The website sante.fr lists all the places where it is possible to be tested. More than 7,000 places are currently listed in France. Since the start of the epidemic, more than 2.4 million people have tested positive for Covid-19 in France.