ABSTRACT
To better understand dynamic changes of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) immune response, a prospective, single-center, cohort study was conducted on longitudinal immune response in 34 COVID-19 convalescent patients over 23 months in Chongqing. Two blood samples from convalescent patients were collected, first sample collected during 10-13 months (M10-13) after infection (pre-SARS-CoV-2 vaccination) and second sample collected during 20-23 months (M20-23) after infection (post-SARS-CoV-2 vaccination). The SARS-CoV-2-specific humoral and cellular immunity were traced by testing total antibody (Ab), anti-nucleocapsid (NP) immunoglobulin M (IgM), anti-NP immunoglobulin G (IgG), and anti-spike (S) IgG Abs, lymphocyte subset count, and Th1 cytokines. Healthy donors (30) were also included in the study as the uninspected healthy controls. Our data showed significant change in mean titer of SARS-CoV-2-specific Ab response from M10-13 to M20-23 included, namely, SARS-CoV-2-specific total Ab as 219 AU/mL increasing to 750.9 AU/mL; anti-NP IgM as 3.5 AU/mL decreasing significantly (p < 0.001) to 0.6 AU/mL; anti-NP IgG as 7.9 AU/mL increasing to 87.1 AU/mL; and anti-S IgG as 499.0 RU/mL increasing to 1,802.3 RU/mL. Our observations suggested that one vaccine dose might have been sufficient for COVID-19 convalescent patients. Larger sample sizes are needed to compare better immune effect of protein subunit vaccine. Besides, compared to healthy donors, patients had decreased CD3+ and CD8+ T lymphocyte counts during two periods. Patients had most cytokines recovered normally within 2 years, but IL-6 level was significantly elevated; however, IL-6 was negatively correlated with IgM and positively correlated with IgG. Changes in cytokines might have been caused by SARS-CoV-2 infection or vaccination. Patients with comorbidities were associated with decreased CD3+ and CD8+ T lymphocytes and lower Ab titers following SARS-CoV-2 vaccination. Vaccination enormously increased humoral immunity beneficial in COVID-19 convalescent patients. Elderly COVID-19 convalescent patients with comorbidities needed more attention.
ABSTRACT
To confirm the relationship between sex and the progression of Coronavirus Disease-19 (COVID-19), and its potential mechanism, among severe patients. For this retrospective study, we included 168 consecutive severe patients with pathogen-confirmed COVID-19 who were hospitalized between January 16th and February 4th, 2020, at Tongji Hospital in Wuhan, China. Clinical characteristics, laboratory parameters, and outcomes were compared and analyzed between males and females. In the present study, we analyzed 168 severe patients with COVID-19, including 86 males and 82 females, and 48 patients (28.6%) were diagnosed as critically ill. Of 86 male patients, 12.8% (11/86) died and 75.6% (65/86) were discharged; of 82 female patients, 7.3% (6/82) died and 86.6% (71/82) were discharged. Eleven laboratory parameters showed significant differences between male and female patients, and six of them were higher during the whole clinical course in patients who died than in patients who were discharged. In adjusted logistic regression analysis, males with comorbidities presented a higher risk of being critically ill than males without comorbidities (OR = 3.824, 95% CI = 1.279-11.435). However, this association attenuated to null in female patients (OR = 2.992, 95% CI = 0.937-9.558). A similar sex-specific trend was observed in the relation between age and critically ill conditions. We highlighted sex-specific differences in clinical characteristics and prognosis. Male patients appeared to be more susceptible to age and comorbidities. Sex is an important biological variable that should be considered in the prevention and treatment of COVID-19.