A recently published Chinese experiment shows that in patients treated with Covid-19, there is an overall good humoral (antibodies) and cellular (lymphocytes) immune response. This reduces our uncertainty in this regard and reassures us a little.
There were many doubts and uncertainties about the immune response in patients treated for Covid-19. In fact, several cases of reinfections have been reported from around the world. In addition, several previously published experiments on this topic were more or less reassuring. A study recently published in the magazine “Immunity” shed some light on this issue.
A generalized immune response in most patients
In this last study, different immune responses were compared by analyzing blood samples from individuals who were cured few weeks ago, recently cured or who had never been infected with SARS-CoV-2. The results are quite reassuring. In fact, most formerly infected people produced antibodies specific to SARS-CoV-2, including antibodies to Protein S, one of the proteins that allow the virus to infect our cells. On the other hand, too few antibodies against other viral proteins have been produced; this production was only registered in two patients.
Scientists have also demonstrated a strong cellular immune response by T lymphocytes in most patients and have found a strong correlation between this response and the development of neutralizing antibodies. An increased presence of NK lymphocytes (natural killer) and innate immune mediators has also been observed. This immune response appears to be able to affect all viral proteins in SARS-CoV-2, in contrast to the antibodies produced, which are often specific for one protein.
As a result of these different defense mechanisms, renewed SARS-CoV-2 infection seems unlikely as long as they are present.
Ways to better understand
The authors concluded their work with the following text: “Our work provides the basis for further analysis of protective resistance to SARS-CoV-2 and understanding the pathogenesis of covid-19, especially in severe cases. This will also influence the development of an effective vaccine against SARS-CoV-2 infection: “In fact, thanks to their research, we know a little more about immunity after SARS-CoV-2 infection and how different parts of the immune system respond to the infection.
All research on naturally acquired immunity provides clues to potential vaccines. Focusing on Protein S has already shown good results in mice. Also looking into making a vaccine that activates the antiviral properties of T lymphocytes which are associated with broader protection makes more sense now with these positive results. Vaccine research is underway worldwide and is gaining momentum, even though testing and production takes time.