Do new variants of the Coronavirus increase the chances of reinfection?
As the coronavirus variants multiply in France, the natural question is whether people who have already been sick with the coronavirus can be sick again from one of the variants. Indeed, if this were the case, the prospect of the achievement of collective immunity, for many associated with a return to normal life, would fade significantly. What is it? Is it possible to be infected with a new variant of the coronavirus when you have already been sick? In this article, we will try to take stock of the scientific knowledge on this subject.
Numerous studies have shown us that in many situations the first infection can provide adequate protection against serious illness for at least a few months. This protection can be achieved either by a humoral immune response (in other words, antibodies) or by a cellular response (T lymphocytes will target diseased cells and eliminate them.). In an almost automatic process, the antibodies will recognize the virus and proceed to its elimination; and this if they are still present in the body after the first infection. On the other hand, specific cells will have to restart the production of antibodies if the body conceives that they are lacking. These specific cells are called memory cells. At the same time, T lymphocytes neutralize cells infected with the virus. The danger most often refers to the different mutations of the virus, which prevent the virus from being recognized by our immune system, so that antibodies and killer cells are unable to act.
As regards the English variant, the very first analyzes turn out to be quite conciliatory. Mutations promote better insertion of the virus into our cells and thus participate in increasing their infectivity. However, they will not change key points of the immune response, unlike the South African and Brazilian variants. Taking into account these last two variants, at least one mutation alters a key protein of the virus. This is the Spike protein, the point of attachment, which allows the virus to attach itself to our cells. It is the main target of antibodies. Initial in vitro studies have shown that antibodies from recovered patients may be 10 times less effective against these variants.
Is it really conceivable that they make the immune response completely obsolete? Considering the increased number of cases recorded in the city of Manaus in Brazil, a city which had hoped to have reached a sufficient threshold of patients to depend on collective immunity, one might be tempted to answer this question in the affirmative. However, there is not enough hindsight to know for sure. In theory, the T cells can be expected to act afterwards and help clear the virus. François Balloux, professor of genetics at University College London, said that through studies, the human body remembers the cellular response almost 17 years after being infected with Sars-CoV-1. If there are no neutralizing antibodies, the response will be slightly slower and will not prevent the onset of some symptoms. But this is enough to avoid severe forms.
A team of immunologists from the Karolinska Institute in Sweden has gathered the latest data from the scientific literature regarding cellular immunity to Sars-Cov-2. Based on these data, this immunity seems very appropriate, so a success. People who do not have detectable anti-SARS-CoV-2 antibodies in their blood samples may still benefit from cellular immunity.
If there are protective measures, there may still be new infections. We just hope that they will not be as serious considering the first infection. This is the case with influenza, where despite the vaccination coverage and immunization of some people, the virus is still spreading. But gradually, the mutations concentrate among themselves, and the variants end up making themselves invisible in the face of an immune system that is ready to fight. It is hardly possible to be successively infected with the influenza virus each year and suffer from it, because the difference between the viruses is very small. For many years, the mutations continued to progress, causing the immune system to no longer recognize the virus at all.
While that future remains elusive for the time being when it comes to Covid-19, more serious cases of infection are not impossible. Indeed, these examples have also been observed, first in a patient from Nevada and, more recently, in Brazil. In the same vein, François Balloux expressed the importance of studying these particular cases, in order to better understand them. The immune system is so complex that it can indeed give different responses to some people.
Only the field remains the true justice of the peace. Will we see more cases among people who are already sick? An answer will be provided in a few weeks. Hopefully we can answer them as soon as possible.
Faced with the rise of new, more contagious variants of the coronavirus, several countries have chosen to make the wearing of the FFP2 type mask compulsory (such as Austria and part of Germany). it is in fact a more protective protective mask, as it is the only type of mask to filter both inhaled and exhaled air, which helps protect the wearer and their environment .
In order to allow the wider world to have access to the FFP2 masks used by medical staff, we have created the online shopping site Achat-Masque-FFP2.fr. You can make your purchase of the FFP2 mask directly online and receive them a few days later directly at your home.