Cell-mediated and humoral immunity during COVID-19 in the Republic of Crimea

The COVID-19 (coronavirus disease 2019) pandemic has spurred the development of highly effective quantitative methods for assessing the adaptive immune response to the SARS-CoV-2 (severe acute respiratory syndrome-related coronavirus 2) virus. In order to assess the humoral component of the immune response, various methods for detecting immunoglobulins A, M, G are widely used. ELISPOT seems to be the most accessible and effective method to assess the level of T cells that specifically respond to the SARS-CoV-2 virus antigens.

The aim. To assess cell-mediated and humoral immunity in COVID-19 in residents of the Republic of Crimea.

Methods. The study was performed on 24 volunteers: the presence of coronavirus antibodies was determined by ELISA method, and the presence of contact with coronavirus proteins – by the ELISPOT “TigraTest®  SARS-CoV-2” method (Generium, Russia). For retrospective study of  humoral immunity in the population, we assessed 10 000 ELISA tests (ECOlab IgM and IgG, Russia) performed in our laboratory for the period from July 2020 to January 2022.

Results. The results show the effectiveness of using the ELISPOT method to detect latent forms of coronavirus infection. It is important to note that there is statistically significant relationship between the timing of the disease and the number of spots in  both antigen panels. After vaccination against SARS-CoV-2, cell-mediated immunity lasts up to 6 months or more.

Conclusions. As a result of the study, it was found that during 2021, the level of  immunization of the population of the Republic of Crimea against COVID-19 has significantly increased; the proportion of residents who have positive IgG test has increased from 27 % to 87 %. The results of ELISPOT studies using a set of reagents for in vitro detection of blood T-lymphocytes that specifically respond to SARS-COV-2 virus antigens (“TigraTest® SARS-CoV-2”) showed that this method is more sensitive than ELISA in detecting latent diseases. 

1. Falzone L, Gattuso G, Tsatsakis A, Spandidos DA, Libra M. Current and innovative methods for the diagnosis of COVID-19 infection (review). Int J Mol Med. 2021; 47(6): 100. doi: 10.3892/ijmm.2021.4933

2. Kozlov VA, Tikhonova EP, Savchenko AA, Kudryavtsev IV, Andronova NV, Anisimova EN, et al. Clinical immunology. A practical guide for infectious disease specialists. Krasnoyarsk: Polikor; 2021. (In Russ.).

3. Cox RJ, Brokstad KA. Not just antibodies: B cells and T cells mediate immunity to COVID-19. Nat Rev Immunol. 2020; 20(10): 581-582. doi: 10.1038/s41577-020-00436-4

4. Hai-Qiong Yu, Bao-Qing S, Zhang-Fu F, Jin-Cun Z, XiaoYu L, Yi-Min L, et al. Distinct features of SARSCoV-2-specific IgA response in COVID-19 patients. Eur Respir J. 2020; 56(2): 2001526. doi: 10.1183/13993003.01526-2020

5. Kudlay D, Kofiadi I, Khaitov M. Peculiarities of the T cell immune response in COVID-19. Vaccines. 2022; 10(2): 242. doi: 10.3390/vaccines10020242

6. Donofrio G, Franceschi V, Macchi F, Russo L, Rocci A, Marchica V, et al. A simplified SARS-CoV-2 pseudovirus neutralization assay. Vaccines (Basel). 2021; 9(4): 389. doi: 10.3390/vaccines9040389

7. Martynova E, Hamza S, Garanina EE, Kabwe E, Markelova M, Shakirova V, et al. Long term immune response produced by the SputnikV vaccine. Int J Mol Sci. 2021; 22(20): 11211. doi: 10.3390/ijms222011211

8. Tukhvatulina AI, Dolzhikovaa IV, Shcheblyakova DV, Zubkovaa OV, Dzharullaevaa AS, Kovyrshina AV, et al. An open, non-randomised, phase 1/2 trial on the safety, tolerability, and immunogenicity of single-dose vaccine “Sputnik Light” for prevention of coronavirus infection in healthy adults. Lancet Reg Health Eur. 2021; 11: 100241. doi: 10.1016/j.lanepe.2021.100241

9. Marcotte H, Piralla A, Zuo F, Du L, Cassaniti I, Wan H, et al. Immunity to SARS-CoV-2 up to 15 months after infection. iScience. 2022; 25(2): 103743. doi: 10.1101/2021.10.08.463699

10. Poteryaev DA, Abbasova SG, Ignatyeva PE, Strizhakova OM, Kolesnik SV, Khamitov RA. Assessment of T-cell immunity to SARS-CoV-2 in COVID-19 convalescents and vaccinated subjects, using TigraTest® SARS-CoV-2 ELISPOT kit. BIOpreparations. Prevention, Diagnosis, Treatment. 2021; 21(3): 178-192. (In Russ.). doi: 10.30895/2221-996X-2021-21-3-178-192

11. Sushentseva NN, Popov OS, Polkovnikova IA, Al’pako SV, Shcherbak SG. Differences in characteristics of T-cell immunity to SARS-CoV-2 in clinically healthy subjects. Bull Exp Biol Med. 2022; 173(1): 133-138. doi: 10.1007/s10517-022-05508-0