A study by researchers at the Medical University of Chongqing, China, with 85 patients recovered from Covid-19, indicates that the CoronaVac vaccine is able to double the amount of neutralizing antibodies and multiply by 4.4 times the level of immunoglobulin IgG in who has had the disease. Preliminary results were released in Cell Discovery, a publication that is part of the British group Nature.
The research participants were between 3 and 84 years old and had become infected with Covid-19, mostly in early 2020. The researchers measured the levels of immunoglobulins and neutralizing antibodies in the patients and selected the five who individually had the lower indicators at the end of 12 months. They received two doses of CoronaVac 21 days apart.
The level of neutralizing antibodies (which protect against eventual reinfection with Sars-CoV-2) among people who had Covid-19, which was 36 a day before the first dose, rose to 108 two weeks after the second dose. .
In the control group, this indicator reached 56 – that is, the amount of neutralizing antibodies generated by the vaccine in those who had already had Covid-19 was double compared to those who had not had the disease.
Among convalescents, the level of immunoglobulin (antibody) IgG, which was 3.68 the day before the vaccine, rose to 47.74 two weeks after the 2nd dose of CoronaVac. It is an amount 4.4 times higher than the level of 10.81 detected in the control group.
IgC is related to humoral immunity, the body’s defense process in which the immunoglobulins found in the blood stream act. The humoral immune response is critical for combating Sars-CoV-2 and also plays a key role in preventing viral reinfection.
Over the 12 months of follow-up in the universe of 85 patients analyzed, the levels of neutralizing antibodies decreased from 631 at the end of the first month to 84 in the last month. In the case of immunoglobulin IgG, the indicator dropped from 28.6 to 7.2 in the same period.
The research results suggest that CoronaVac stimulates the humoral memory of convalescent patients, accelerating the production of neutralizing antibodies and their level of circulation in the bloodstream.