Analysis by researchers from Israel focused on 4,800 employees and observed levels of antibodies over six months
A study by doctors at Sheba Medical Center, the largest hospital in Israel, in partnership with the research institute Gertner found that the immunity offered by vaccines from Pfizer against a Covid-19 they decrease after the first two months of the application of the second dose, which does not mean, however, that it does not continue to protect against severe manifestations and deaths caused by the disease. In all, 4,800 health workers in the country were followed up for half a year and underwent IgG/IgM tests monthly to detect the amount of antibodies against the virus. The final analysis of the data, published in the New England Journal of Medicine, which found that the level of IgG antibodies – which are in the “front line” of the immune system against the disease – dropped “quickly” from the second month after immunization , showing a “relatively slow” decline thereafter, especially among men, people over 65 years of age and immunosuppressed. “The vaccine induces an increase in IgG and a neutralizing antibody response between 7 and 14 days after the application of the second dose. Lower levels of antibodies were developed in older people, men and people with immunosuppressive conditions, which suggests that the concentration of antibodies in these populations decreases earlier than in other populations”, states an excerpt from the research. According to the analysis, a decrease in antibodies was noticed between the peak of immunization, which occurs between 21 and 40 days after the second dose, and the 84th day after the vaccine cycle is completed.