Time-related changes in the titer of virus neutralizing antibodies against SARS-CoV-2 after COVID-19 in patients with HIV infection

Objective. To assess the time-related changes in the titer of virus neutralizing antibodies to SARS-CoV-2 in patients with HIV infection within 6 months after experienced COVID-19, and to identify factors associated with the intensity and duration of the natural humoral immune response.Materials and Methods. А prospective study was performed in 102 HIV-infected patients who had COVID-19 without previous vaccination, the titer of virus neutralizing antibodies to SARS-CoV-2 was identified by microneutralization assay using the standard method, the follow-up period was 6 months. Patients were enrolled in St. Petersburg from October 2020 to January 2022. The possible impact of clinical and laboratory characteristics of HIV infection and the severity of COVID-19 on antibody titer was assessed.Results and discussion. А high antibody titer (>1:160) was detected at 1 month in 15 patients (14.7%), at 3 months — in 5 of 44 patients; at 6 months — in 3 of 26 patients. There was a statistically significant positive correlation of the titer at 1 month with an undetectable HIV viral load and the Cd4+lymphocytes count in the blood. Cases of a late increase in antibody titer (after 3 and 6 months) were registered without COVID-19 re-infection along with improvement of the immune status on antiretroviral therapy.Conclusion. А low incidence of effective humoral immune response 1 month after COVID-19 infection was demonstrated in HIV-infected patients without vaccination against SARS-CoV-2. Single cases of delay in antibody titer increase with an immune status improvement were observed.