The Haute Autorité de Santé (HAS) spoke on June 3 on the possibility of carrying out a rapid diagnostic orientation test (TROD) during the first injection of the vaccine against Covid-19. What is his opinion? Who should take a test on the first appointment?
Identify asymptomatic Covid-19 patients
In an opinion issued on February 11, the HAS recommended administering a single dose of vaccine, whether messenger RNA (Pfizer or Moderna) or adenovirus (AstraZeneca), to people who have had a Covid-19 infection. , confirmed by an RT-PCR or antigen test, ” whether or not they have developed a symptomatic form of Covid-19 “. However, even if the vaccination campaign is accelerating in France, the HAS “ estimates that 23% of the population has been infected while only 8% have been detected by PCR or antigen test “. Faced with this observation, the agency considers that it would be useful to identify people who have been infected without knowing it. In order to optimize the use of vaccine doses and in order to immunize millions of people more quickly, “ HAS considers that screening by TROD (…) asymptomatic forms of Covid-19 at the same time as the administration of the first dose of vaccine could thus make it possible to inject only a single dose when this test turns out to be positive “. Concretely, this methodology will make it possible to release doses as well as vaccination slots.
Who will be affected by the serological test during the first injection?
Serological tests will be deployed in vaccination centers. The health authority recommends carrying out “ this test in immunocompetent people with no known history of SARS-CoV-2 infection “. Immunocompetence is the body’s ability to produce antibodies following infection with a pathogen. It would concern in particular people who are likely to have an asymptomatic form of Covid-19, that is to say young adults. However, the HAS “ stresses that before generalizing this approach, it is essential to verify (…) that this screening does not disrupt the organization of the current vaccination “.
How does the test work?
The rapid serological test, also called TROD, consists of taking a drop of blood from the fingertip. The purpose of this device is to look for the presence of antibodies in the blood. The result is given in about 15 minutes. Thus, the patient will be able to know if he has a history of Covid-19. This is the same length of time the person who has just been vaccinated should be monitored. The test could therefore be carried out during this post-vaccination surveillance period. If the result is positive, the second appointment to receive the second dose will be canceled because the person ” will have completed their vaccination cycle “.
Reinforced immunity
A single dose of vaccine is indeed recommended for a person who has contracted Covid-19, regardless of the age of the contamination, because these former patients make their own antibodies. The immune system maintains a memory and provides protection against the virus. Therefore, it is best for those who have recovered from the disease to receive the vaccine at least three months after infection. On the other hand, recent scientific data proves that “ the protection conferred by a single dose injected into a person with a history of infection is greater than that given by two doses injected into a person without a history “.
