Dynamics of specific immune response and autoantibodies against the background of vaccination with the Gam-COVID-Vac in healthy young individuals

Introduction

The coronavirus disease 2019 (COVID-19) pandemic, etiologically associated with the SARS-CoV-2 virus, has affected all countries of the world and once again attracted attention to the implementation of timely methods of preventing viral infections through specific immunization of wide sections of the population. Vaccination is an effective and safe method for combating infectious diseases [1]. Since the beginning of 2021, mass vaccination of citizens has started in all regions of the Russian Federation according to standard operating procedures and procedures for its implementation, developed by the Ministry of Health of the Russian Federation [2].

In the Russian Federation (RF), there are several types of vaccines against COVID-19, but the most commonly used is the two-component vaccine Gam-COVID-Vac (Sputnik V) [3]. Its effectiveness against COVID-19 has been well studied and confirmed both in the RF [4, 5, 6] and abroad [7, 8, 9]. However, some issues related to the safety of its use in human immunoinflammatory diseases, the incidence of new autoimmune diseases, and the production of autoantibodies after immunization remain unclear [1, 3]. 

There have been isolated cases of the onset of autoimmune diseases in individuals who received the Gam-COVID-Vac (Sputnik V) vaccine [10], as well as the production of antibodies to double-stranded deoxyribonucleic acid (anti-dsDNA) and phospholipids (aPL) [11], which are characteristic of immune-inflammatory rheumatic diseases, immunothrombosis, and obstetric pathology [12,13]. 

Objective

To assess the dynamics of the formation of a specific immune response to the SARS-CoV-2 virus, the production of autoantibodies and the relationship between them during vaccination with Gam-COVID-Vac (Sputnik V) in healthy young individuals.

Materials and methods

The study is a continuation of the final (diploma) qualification works of Yu.A. Saveliev and V.I. Veresh, completed under the supervision of Professor A.A. Baranov, the topics of which were approved on November 15, 2023 (minutes No. 3) at the council of the medical faculty of the Federal State Budgetary Educational Institution of Higher Education Yaroslavl State Medical University of the Ministry of Health of Russia.

Based on the Order of the Ministry of Health of the Russian Federation dated 03.02.2021 No. 47n [14] and in accordance with the instructions for the Gam-COVID-Vac (Sputnik V) vaccine [15], vaccination of university students with the two-component Gam-COVID-Vac (Sputnik V) vaccine was organized from March to May 2021 at the medical center of the Federal State Budgetary Educational Institution of Higher Education Yaroslavl State Medical University of the Ministry of Health of Russia (chief physician - M.A. Borodina). Before vaccination against COVID-19, the person to be vaccinated or his/her legal representative was informed about the need for vaccination, possible post-vaccination reactions and complications, given a patient questionnaire to fill out, and provided with informed voluntary consent for medical intervention in accordance with the requirements of Article 20 of the Federal Law of 21.11.2011 No. 323-FZ "On the Fundamentals of Health Protection of Citizens in the Russian Federation", and given a leaflet with information material. 

The retrospective study included 45 apparently healthy students who had been fully vaccinated with two components of the Gam-COVID-Vac (Sputnik V) vaccine at the university medical center and had three visits to the center for observation. Before the study, all students signed an informed consent to undergo examination and collection of biological material. Among them, there were 32 women (71.0%) and 13 men (29.0%) aged 19 to 28 years, the median age was 23.00 [22.00; 24.00] years. Biological material for the study was collected three times: before vaccination with the first component of the vaccine, 3 weeks after its administration (before the administration of the second component), and 3-4 weeks after the administration of the second component.

All 45 individuals underwent dynamic determination of IgG and IgM antibodies to SARS-CoV-2 in the blood serum by enzyme-linked immunosorbent assay (ELISA) using the D-5501 (SARS-CoV-2-IgG-ELISA-BEST) and D-5502 (SARS-CoV-2-IgM-ELISA-BEST) test systems from Vector-Best JSC (Russia) according to the manufacturer's instructions. The study result was expressed as a positivity coefficient (PC) in conventional units (CU), results with a PC of more than 1.1 CU were considered positive, negative – with a PC <0.8 CU, questionable or borderline if 0.8 CU <PC < 1.1 CU. All 45 students also had IgG anti-dsDNA determined three times by the ELISA method using kits from Vector-Best (Russia) (Vecto-dsDNA-IgG, A-8656). According to the manufacturer’s instructions, the reference values for IgG anti-dsDNA were 0-25.0 IU/ml.

In 29 students, 23 women and 6 men aged 20 to 26 years, median age 23 years [21.00; 24.00] the concentration of IgM and IgG antibodies to cardiolipin (IgM aCL, IgG aCL) was also tested three times by ELISA. ORGenTec Diagnostika kits were used (cat. number: 416-5150, Germany). According to the manufacturer’s instructions, the reference values for IgM aCL were 0-7.0 MPL U/ml and for IgG aCL – 0-10 GPL U/ml. The optical density of the ELISA results was read on a multifunctional microplate photometer with an 8-channel optical system ImmunoChem-2100. The study was conducted in the clinical diagnostic laboratory of OOO Set, which is the practice base of the Department of Outpatient Therapy, Clinical Laboratory Diagnostics and Medical Biochemistry of Yaroslavl State Medical University.

Statistical processing of the results was performed using the Statistica 10.0 software package (StatSoft, USA), including generally accepted methods of parametric and nonparametric analysis, including the Wilcoxon test (paired samples). The results are presented as a median (Me) with an interquartile range [25th; 75th percentiles]. Correlation analysis was performed using the Spearman method. Fisher’s exact test and the χ² test were used to compare the frequencies of qualitative features in unrelated groups. Differences were considered statistically significant at p <0.05.

Results

In the examined individuals, before vaccination with Gam-COVID-Vac (Sputnik V), the levels of IgM SARS-CoV-2 and IgG SARS-CoV-2 were low and within the reference values ​​(see Table 1). In no case did the PC exceed the value of 1.1 u.u., adopted, according to the manufacturer's instructions, as an indicator of the presence of specific antibodies to SARS-CoV-2 in the human body. After the administration of the first component of the vaccine, the level of IgM SARS-CoV-2 significantly increased compared with the period before vaccination (PC: 0.28 [0.17; 1.25] u.u. and 0.07 [0.04; 0.09] u.u., respectively, p <0.001). It remained significantly high, compared with the baseline period, and after the 2nd stage of vaccination (PC: 0.13 [0.07; 0.37] u.u., p <0.001), but underwent a significant decrease after the introduction of the second component of the vaccine, compared with the data after the first stage (p <0.01). After the first stage of vaccination, in 14 (31.11%) people, the CP for IgM SARS-CoV-2 exceeded 1.1 u.u., but after the second stage, its frequency decreased to 11.11%. After the introduction of the first component of the vaccine, compared with the baseline period, a sharp increase in the concentration of IgG SARS-CoV-2 was noted (PC: 10.24 [6.78; 12.44] u.u. and 0.06 [0.05; 0.11] u.u., respectively, p <0.001), as well as the occurrence of their high values. The detection rate of IgG SARS-CoV-2 (PC: more than 1.1 u.u.) after vaccination with the first component was 91.11%, and after the introduction of the second component, it reached 100.0%. In addition, after the first stage of vaccination, the number of individuals with high (PC more than 10.0 u.u.) IgG SARS-CoV-2 values was 26 (57.78%), and after the second it increased to 32 (71.11%). At the same time, the median values after the first and second stages of vaccination did not significantly differ from each other (p>0.05). Before the start of vaccination, no correlation was found between the level of IgG and IgM antibodies to SARS-Cov-2 (r = 0.18, p=0.23). After the introduction of the first component, it was significant and amounted to (r = 0.53, p=0.0002), and after the second – (r = 0.48, p=0.002).

The values of IgG anti-dsDNA before vaccination and after the introduction of the first component of the vaccine did not differ significantly (p>0.05). However, after the second stage, the level of IgG anti-dsDNA increased and almost reached significant differences with the initial one (p=0.05). IgG anti-dsDNA in low concentrations were detected in individuals (2.22%) after each stage of vaccination.

During the vaccination process, the IgM aCL values showed a clear tendency to increase, especially after the introduction of the second component, compared to the period before vaccination, without, however, reaching significant differences (0.91 [0.67; 1.44] MPL IU/ml and 0.75 [0.44; 1.50] MPL IU/ml, respectively, p=0.07). Only in one case (3.45%), after the 1st introduction of the first component of the vaccine, IgM aCL were detected in low concentrations. 

The concentration of IgG aCL also increased, reaching significant differences after the second stage of vaccination, compared with the period before it (1.37 [1.02; 1.51] GPL IU/ml and 1.00 [0.81; 1.40] GPL IU/ml, respectively, p <0.05). However, in none of the examined individuals did the IgG aCL values exceed the upper limit (10 GPL IU/ml) of the reference range. 

The values ​​of IgM antibodies to SARS-Cov-2 after administration of the first and second components of the vaccine did not correlate with the concentration of IgG anti-dsDNA (r=0.01, p=0.92 and r= -0.05, p=0.74, respectively), IgM aCL (r= -0.02, p=0.93 and r= -0.03, p=0.89, respectively) and IgG aCL (r=0.02, p=0.91 and r=0.07, p=0.70, respectively). 

After vaccination with the first component of the vaccine, a significant negative correlation was found between the concentration of SARS-Cov-2 IgG and the values of IgG anti-dsDNA (r= -0.37, p=0.01), which was absent after the second stage of vaccination (r= -0.12, p=0.44). The values of SARS-Cov-2 IgG did not correlate with the level of IgM aCL after both stages of vaccination (r= -0.02, p=0.93 and r= -0.03, p=0.89, respectively). The concentration of SARS-Cov-2 IgG after the first stage did not correlate with IgG aCL (r= -0.23, p=0.22), and after the second stage, there was a direct relationship, which, however, did not reach the level of significance (r=0.35, p=0.06).

We conducted a comparative analysis of the dynamics of the production of specific IgM and IgG antibodies to SARS-CoV-2, as well as IgG anti-dsDNA, IgM aCL, and IgG aCL between women and men at different stages of vaccination (Table 2). The 32 women and 13 men included in the study did not differ significantly in age. The median age for women was 23.00 [21.50; 25.00] years, and for men, it was 24.00 [23.00; 24.00] years (p >0.05). Before the start of vaccination, no significant differences were found in the compared indicators between the two cohorts of students (p >0.05, in all cases). 

After the introduction of the first component of the vaccine, men, compared with women, showed a significantly higher level of IgG antibodies to SARS-CoV-2 (PC 12.44 [10.24; 15.78] u.u. and PC 9.75 [4.50; 11.95] u.u., respectively, p <0.01), with an almost equal frequency of detection of their high values ​​(92.31% and 90.63%). In addition, men showed a tendency toward an increase in both the level of IgM antibodies to SARS-CoV-2 and the occurrence of their high values. After the introduction of the second component, these differences leveled out.

In contrast, after the 2nd stage of vaccination, women showed a significant increase in the IgG aCL level (1.41 [1.02; 1.62] GPL IU/ml and 1.00 [0.87; 1.32] GPL IU/ml, respectively, p <0.05) compared to individuals of the opposite sex, as well as a tendency toward an increase in the concentration of IgG anti-dsDNA and IgM aCL (p >0.05). At the same time, only in women after the administration of the first or second components of the drug were IgM aCL and IgG anti-dsDNA detected in low titers. IgG aCL were not detected in any case.

Thus, after the administration of the first component of the vaccine, a 24-year-old woman was found to have IgM aCL in a low concentration (9.28 IU/ml, reference values ​​0-7.0 MPL IU/ml), but after the administration of the second component, their level (3.38 MPL IU/ml) decreased to normal values. In one 28-year-old woman, after the administration of the first component of the vaccine, IgG anti-dsDNA was detected (31.09 IU/ml, reference values ​​0-25.0 IU/ml), after the administration of the second component, their values ​​(7.03 IU/ml) were within the reference interval. In another 23-year-old woman, after the 2nd stage of vaccination, IgG anti-dsDNA was also detected in a low titer (27.86 IU/ml).

Discussion

In this study, we studied the dynamics of the formation of specific immunity to the SARS-CoV-2 virus after vaccination with Gam-COVID-Vac (Sputnik V) in healthy young people. At the time of vaccination, this cohort had no signs of acute SARS-Cov-2 infection and had not been immunized against this virus. This is evidenced by the levels of IgM SARS-CoV-2 and IgG SARS-CoV-2 in the blood serum of students before the administration of the first component of the vaccine. The medians of their PC and interquartile range were significantly lower than the values that, according to the manufacturer's instructions, were considered negative (PC <0.8 u.u.). At the same time, PC in no case exceeded the value of 1.1 u.u., accepted as an indicator of the presence of specific antibodies to SARS-CoV-2 in the human body.

We determined IgG antibodies to SARS-CoV-2 in blood serum using a semi-quantitative ELISA method using test systems from Vector-Best JSC. Currently, there is data on good (98.4–99.4%) comparability and high (98.9%) specificity of the results of the study to detect IgG antibodies to SARS-CoV-2 using diagnostic ELISA kits from this company, with both semi-quantitative and quantitative assessment of the results [16]. 

According to our data, the detection rate (PC: more than 1.1 u.u.) of IgG SARS-CoV-2 after vaccination with the first component was 91.11%, and after the introduction of the second component, it reached 100.0%, which is consistent with the results (92.3–99.5%) of other authors who used the same diagnostic test systems in their work [16]. Platonova T.A. et al. [5], 3 weeks after the first vaccination with the Gam-COVID-Vac vaccine, detected IgG antibodies to SARS-CoV-2 in 56.7% (PC more than 1.1 u.u.) of the employees of the medical organization, and 3–4 weeks after the introduction of the second component, in 99.4% of people.

Inviyaeva E.V. et al.[17] revealed the formation of specific antiviral antibodies of class G to SARS-CoV-2 in 97.5% of vaccinated women and 92.3% of vaccinated men. In our study, the frequency of detection of IgG antibodies to SARS-CoV-2 after the administration of the first component was 90.63% in women and 92.31% in men. Moreover, the level of IgG antibodies to SARS-CoV-2 in men was significantly higher than that in women. After the administration of the second component, the frequency of detection of IgG antibodies to SARS-CoV-2 reached 100.0% for both men and women.

In the present study, after the first stage of vaccination, the number of individuals with high (PC more than 10.0 u.u.) SARS-CoV-2 IgG values was 57.78%, and after the second it increased to 71.11%. This is consistent with the data of Kazakov S.P. et al. [16], who, when studying the blood serum obtained on days 22–25 after the administration of the second component of the vaccine from 202 Gam-COVID-Vac (Sputnik V) vaccinated individuals who were not previously immunized and did not have antibodies to SARS-CoV-2 before vaccination, found an increase in the SARS-CoV-2 IgG titer (PC: more than 10.0 u.u.) by 80.7%. At the same time, the authors believe that the “protective” level of IgG antibodies to SARS-CoV-2 of more than 150 BAU/ml, detected by quantitative methods, may correspond to values of 10 u.u. [16].

When assessing the dynamics of IgM SARS-CoV-2 values during vaccination, we found that after the introduction of the first component of the vaccine, their level increased significantly compared with the period before vaccination. After the introduction of the second component, it significantly decreased compared to the previous one, but remained higher compared to the baseline data. At the same time, in 31.11% of cases after the first stage of vaccination, PC for IgM SARS-CoV-2 exceeded 1.1 u.u., but over time its frequency decreased to 11.11%. 

According to Kazakov S.P. et al. [16], after vaccination with the second component of Gam-COVID-Vac (Sputnik V), the detection rate (PC more than 1.1 u.u.) of IgM antibodies to SARS-Cov-2 was 24.8%. In all individuals with a “positive” result for IgM antibodies to SARS-Cov-2, the values of IgG antibodies to SARS-Cov-2 were higher than the reference values. We also found a positive correlation between the level of IgM antibodies to SARS-Cov-2 and the concentration of IgG SARS-Cov-2 after vaccination, especially after the administration of the first component of the vaccine (r=0.53, p=0.0002). On the contrary, Drapkina O.M. et al. [18] did not note an increase in the level of IgM SARS-CoV-2 before and after the administration of the first and second components of the Gam-COVID-Vac vaccine (Sputnik V), which, according to the authors, indicates the absence of laboratory signs of acute COVID-19 in patients.

Taking into account the ability of vaccines to activate various inflammatory processes, one of the safety indicators in all studies is the assessment of the incidence of new immunoinflammatory diseases, the development of their exacerbations, an increase in the risk of thrombosis and the induction of autoantibody synthesis [1]. In immunoinflammatory rheumatic diseases, the incidence of disease exacerbations after vaccination with Gam-COVID-Vac (Sputnik V) is low (5–7%) and has no statistically significant association with antirheumatic therapy [1]. Of the 172 patients with rheumatoid arthritis who received two components of the combined vector vaccine Gam-COVID-Vac (Sputnik V), a relapse of the disease, which required intra-articular administration of glucocorticosteroid and replacement of the immunosuppressive drug, was observed in only 1 (0.6%) case [19]. In a study that included 325 patients with immune-inflammatory rheumatic diseases and 138 individuals without them, after vaccination with the first component of Gam-COVID-Vac (Sputnik V), the incidence of local and systemic adverse events in patients was statistically significantly lower compared to the control (20.3 and 38.4%, respectively) [20]. 

 Vera-Lastra O. et al.[10] conducted a retrospective study of patients with newly diagnosed autoimmune diseases that developed after vaccination against COVID-19 in two hospitals in Mexico City and Buenos Aires between March 2021 and December 2022. A total of 123 post-vaccination effects were recorded, of which 28 occurred after the administration of the Sputnik V vaccine – 14 in women and 14 in men. In the majority (57%) of patients, clinical manifestations developed after the administration of the second component of the vaccine. They were mainly concerned with neurological diseases, including Guillain-Barré syndrome, neuromyelitis optica spectrum disorder, myasthenia gravis, and chronic immune demyelinating polyneuropathy. The development of dermatomyositis in a 40-year-old woman with antinuclear antibodies was observed, as well as adult Still's disease in a 20-year-old woman with a significant increase in ferritin concentration, but without the production of rheumatoid factor, antibodies to cyclic citrullinated peptide, IgG antibodies to SS-A, SS-B nuclear antigens. According to the researchers, they met the criteria for an autoimmune/inflammatory syndrome caused by the adjuvants of the Sputnik V vaccine.

It has been proven that vaccination with Gam-COVID-Vac (Sputnik V) prevents severe COVID-19 with the development of fatal outcomes, pulmonary embolism, and venous and arterial thrombosis [6]. According to Drapkina O.M. et al. [18], based on the results of dynamic observation for more than 3 months of 137 volunteers without signs of acute respiratory viral infection who were vaccinated with Gam-COVID-Vac (Sputnik V), against the background of the formation of effective humoral immunity against the SARS-Cov-2 virus, there was no negative effect on the process of plasma hemostasis and the development of thromboembolic complications in vaccinated individuals. According to Inviyaev E.V. et al. [17], the Gam-COVID-Vac vaccine is effective and induces a specific humoral immune response, which is not accompanied by serious disturbances in the functioning of the immune system.

A series of studies were devoted to assessing the effect of the Gam-COVID-Vac vaccine (Sputnik V) on the production of autoantibodies in young women of reproductive age. One of them studied the dynamics of the formation of a specific immune response to SARS-Cov-2 and the synthesis of aPL – IgM and IgG aCL, IgM and IgG antibodies to β₂-glycoprotein-1, annexin V, and phosphatidylserine [21]. The prospective study included 51 women aged 31.0 (26.0–36.0) years vaccinated against SARS-Cov-2. IgG antibodies to SARS-CoV-2 were detected in 98.1% of the vaccinated patients. After vaccination, compared with baseline values, a slight decrease in the level of IgG aCL, IgM antibodies to β₂-glycoprotein-1, IgG aPL, IgG antibodies to annexin V and an increase in IgM antibodies to annexin V were noted. The level of aPL did not exceed the reference values in almost all patients. An increase in the level of aPL was observed only in 5.9% of women. Our data also indicate a low frequency of detection of IgM aCL in women after vaccination with Gam-COVID-Vac (Sputnik V). At the same time, we did not detect the hyperproduction of IgG aCL.

In another study, the effect of immunization with the Gam-COVID-Vac (Sputnik V) vaccine on the level of autoantibodies and hormones reflecting the ovarian reserve and the relationship between them was assessed on a cohort of women of reproductive age [11]. From December 2020 to December 2021, 120 women who were immunized with Gam-COVID-Vac (Sputnik V) were examined. After vaccination, specific IgG antibodies to SARS-CoV-2 were detected in the blood serum of 98.3% of the vaccinated women. No increase in the level of autoantibodies was found, except for IgM antibodies to phosphatidylethanolamine and IgG anti-dsDNA, which were transient, which is consistent with the results of our study. In addition, no correlation was found between the level of autoantibodies and hormones reflecting the ovarian reserve. The authors believe that vaccination with Gam-COVID-Vac (Sputnik V) does not have a negative impact on the ovarian reserve and does not cause the development of autoimmune reactions and the associated decrease in reproductive potential in women [11].

This group of authors also found that IgG anti-dsDNA were the only type of autoantibodies, the increase of which was detected in women after vaccination significantly more often than before it [22]. A dynamic study of serum samples with a high concentration of IgG anti-dsDNA, performed 3 months after the end of vaccination, showed normalization of their level, which confirms the transient nature of their increase [22]. A similar pattern was found by us. It should be noted that in our study, women with IgG anti-dsDNA or IgM aCL did not have clinical manifestations of systemic lupus erythematosus or antiphospholipid syndrome, and the titer of these autoantibodies did not reach the values accepted as laboratory criteria for these diseases. The results of these studies convincingly prove that changes in the immune system in vaccinated women are transient and do not lead to the launch of autoimmune reactions that can affect the reproductive function of women [22].

In general, according to experts from various international and national scientific societies and associations, the benefits of vaccination significantly outweigh the potential harm associated with the development of adverse events because it reduces the risk of SARS-CoV-2 infection and severe COVID-19 [1].

Conclusion

The results showed that a specific antiviral immune response is effectively formed in young men and women after vaccination with the Gam-COVID-Vac (Sputnik V) vaccine. It is more pronounced in men than in women, especially after the administration of the first component of the vaccine, but is not associated with the production of certain types of autoantibodies characteristic of immune-inflammatory rheumatic diseases. In women, after vaccination, in some cases, there is an induction of the synthesis of IgG anti-dsDNA or IgM aCL, but their concentration is low and transient. It is necessary to conduct prospective studies on this issue on large cohorts of the population.