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Background During the ongoing coronavirus disease COVID-19 pandemic, many individuals were infected with and have cleared the virus, developing virus-specific antibodies and effector/memory T cells. An important unanswered question is what levels of T cell and antibody responses are sufficient to protect from the infection. Methods In 5340 Moscow residents, we evaluated anti-SARS-CoV-2 IgM/IgG titers and frequencies of the T cells specific to the membrane, nucleocapsid, and spike proteins of SARS-CoV-2, using IFNγ ELISpot assay. Additionally, we evaluated the fractions of virus-specific CD4+ and CD8+ T cells using intracellular staining of IFNγ and IL2 followed by flow cytometry. We analyzed the COVID-19 rates as a function of the assessed antibody and T cell responses, using the Kaplan-Meyer estimator method, for up to 300 days post-inclusion. Results We showed that T cell and antibody responses are closely interconnected and are commonly induced concurrently. Magnitudes of both responses inversely correlated with infection probability. Individuals positive for both responses demonstrated the highest levels of protectivity against the SARS-CoV-2 infection. A comparable level of protection was found in individuals with antibody response only, while the T cell response by itself granted only intermediate protection. Conclusions We found that the contribution of the virus-specific antibodies to protection against the SARS-CoV-2 infection is more pronounced than that of the T cells. The data on the virus-specific IgG titers may be instructive for making decisions in personalized health care and public anti-COVID-19 policies.

BackgroundCoronavirus disease COVID-19 has spread worldwide extremely rapidly. Although many individuals have been infected and have cleared the virus, developing virus-specific antibodies and effector/memory T cells, an important question still to be answered is what levels of T cell and antibody responses are sufficient to protect from the infection.MethodsIn 5,340 Moscow residents, we evaluated the anti-SARS-CoV-2 IgM/IgG titers and the frequencies of the T cells specific to the nucleocapsid, membrane, and spike proteins of SARS-CoV-2, using IFNγ ELISpot, and we also evaluated the fractions of virus-specific CD4+ and CD8+ T cells using intracellular staining of IFNγ and IL2 followed by flow cytometry. Furthermore, we analyzed the post-inclusion COVID-19 rates as a function of the assessed antibody and T cell responses using the Kaplan-Meyer estimator method.ResultsWe showed that T cell and antibody responses are closely interconnected and commonly are induced concurrently. Individuals positive for both antibody and T cell immunities demonstrated the highest levels of protectivity against the SARS-CoV-2 infection, indistinguishably from individuals with antibody response only. Meanwhile, individuals with T cell response only demonstrated slightly higher protectivity than individuals without both types of immunity, as measured from N-protein–specific or CD4+IL2+ T cells. However, these individuals were characterized by higher IgG titers than individuals without any immunity, although the titers were below the seropositivity cut-off.ConclusionsThe results of the study indicated the advantage of serology testing over the analysis of T cell responses for the prediction of SARS-CoV-2 infection rates on a populational level.

The review presents data on the frequency of detection of drug resistant (DR) tuberculosis mycobacteria (MTB) as well as on the change in DR patterns in Russia and abroad from the mid-50s of the 20th century till the present. Along with the well-known mechanisms for DR MTB development, it tells about new research describing mutations associated with drug resistance.

Background: After the breakup of the Soviet Union, the annual incidence of tuberculosis (TB) in children 15-17 years of age increased in the Russian Federation from 16 per 100 000 population in 1992 to 37 per 100 000 in 2009, and new control measures were implemented. Methods: Children were screened annually for TB exposure with a tuberculin skin test (TST) at age 1-8 years. If positive, they were investigated for active TB. If no active TB was found, they were treated with isoniazid for 4-6 months; they then underwent 6-monthly skin tests (which included two recombinant proteins) until negative and annual skin tests thereafter. From the age of 8 years, the yearly follow-up was performed using the skin test that included two recombinant proteins, either until they became negative, developed active TB, or turned 18 years. Results: The annual incidence of TB in Russian children decreased from 19.1 per 100 000 population in 2001 to 8.3 per 100 000 population in 2018. Conclusions: Annual screening for TB exposure with treatment for latent or active TB has reduced the annual incidence of TB in Russian children aged 15-17 years to 1992 levels.