Comprehensive analyses reveal the impacts of vaccination status and physiological variables in early infection on viral persistence in COVID-19 patients: a retrospective single-center cohort study

BACKGROUNDViral persistence is a crucial factor that influences the communicability of SARS-CoV-2 infection. However, the impacts of vaccination status and physiological variables on viral RNA shedding have not been adequately clarified. METHODSIn this study, we retrospectively collected the clinical records of 377 hospitalized COVID-19 patients, which contained unvaccinated patients and patients received two doses of an inactivated vaccine or an mRNA vaccine. Firstly, we analyzed the impacts of vaccination on disease severity and viral RNA persistence. Next, to clarify the impacts of physiological variables on viral RNA shedding in COVID-19 patients, we retrieved 49 laboratory variables and analyzed their correlations with the duration of viral RNA shedding. Finally, we established a multivariate regression model to predict the duration of viral RNA shedding. RESULTSOur results showed that both inactivated and mRNA vaccines significantly reduced the rate of moderate cases, while the vaccine related shortening of viral RNA shedding were only observed in moderate patients. Correlation analysis showed that 10 significant laboratory variables were shared by the unvaccinated mild patients and mild patients inoculated with an inactivated vaccine, but not by the mild patients inoculated with an mRNA vaccine. Moreover, we demonstrated that a multivariate regression model established based on the variables correlating with viral persistence in unvaccinated mild patients could predict the duration of viral shedding for all groups of patients. CONCLUSIONSVaccination contributed limitedly to the clearance viral RNA in COVID-19 patients. While, laboratory variables in early infection could predict the persistence of viral RNA.

Immunogenicity and safety of an inactivated SARS-CoV-2 vaccine in people living with HIV-1

BackgroundIt has been proven that inactivated COVID-19 vaccines are safe and effective in general population with intact immunity. However, their safety and immunogenicity have not been demonstrated in people living with HIV (PLWH). Methods42 HIV-1 infected individuals who were stable on cART and 28 healthy individuals were enrolled in this study. Two doses of an inactivated COVID-19 vaccine (BIBP-CorV) were given 4 weeks apart. The safety and reactogenicity of the vaccine were evaluated by observing clinical adverse events and solicited local and systemic reactions. Humoral responses were measured by anti-spike IgG ELISA and surrogate neutralization assays. Cell-mediated immune responses and vaccine induced T cell activation were measured by flow cytometry. FindingsAll the HIV-1 infected participants had a CD4+ T cell count of above 200 cells/L both at baseline and 4 weeks after vaccination. No solicited adverse reaction was observed among all participants. Similar binding antibody, neutralizing antibody and S protein specific T cell responses were elicited in PLWH and healthy individuals. Further analyses showed that PLWH with low baseline CD4+/CD8+ T cell ratios (<0{middle dot}6) generated lower antibody responses after vaccination than PLWH with medium (0{middle dot}6[~]1{middle dot}0) or high ([≥]1{middle dot}0) baseline CD4+/CD8+ T cell ratios (P<0{middle dot}01). The CD3+, CD4+ and CD8+ T cell counts of PLWH decreased significantly after vaccination, but it did not lead to any adverse clinical manifestation. Moreover, we found that the general burden of HIV-1 among the PLWH cohort decreased significantly (P=0{middle dot}0192) after vaccination. And the alteration of HIV-1 viral load was not significantly associated with the vaccine induced CD4+ T cell activation. InterpretationOur data demonstrate that the inactivated COVID-19 vaccine is safe and immunogenic in PLWH who are stable on cART with unsuppressed CD4 counts. FundingThis work was funded by the National Natural Science Foundation of China (Grant No. 81971559, 82041010). Research in contextO_ST_ABSEvidence before this studyC_ST_ABSThe safety and efficacy of inactivated COVID-19 vaccines have been validated in general population with intact immunity. However, their safety and immunogenicity have not been demonstrated in people living with HIV (PLWH). Added value of this studyOur study provides the first evidence to show humoral and cellular immune responses to an inactivated vaccine in PLWH who have been stable on cART with good CD4 cell counts. We found that participants with HIV-1 generated antibody and T cell responses comparable with those of healthy individuals after two-dose vaccination. The baseline CD4/CD8 ratios while not the absolute CD4+ T cell counts were shown to be associated with the magnitudes of vaccine induced antibody responses. Moreover, we showed that the vaccine induced T cell activation did not increase the viral burden in PLWH on cART. On the contrary, the levels of plasma HIV-1 RNA decreased among a significant percentage of PLWH. Implications of all the available evidenceOur data demonstrate that the inactivated COVID-19 vaccine is safe and immunogenic in PLWH who are stable on cART with unsuppressed CD4 counts and indicate that this vaccine might be protective and efficacious against COVID-19 for people with HIV.

Pre-existing antibodies targeting a dominant linear antibody epitope on SARS-CoV-2 S2 cross-reacted with commensal gut bacteria and shaped immune responses elicited by a candidate vaccine

The origins of pre-existing SARS-CoV-2 cross-reactive antibodies and their potential impacts on vaccine efficacy have not been fully clarified. In this study, we demonstrated that S2 was the prevailing target of the pre-existing S protein cross-reactive antibodies in both healthy human and SPF mice. A dominant antibody epitope was identified on the connector domain of S2 (1147-SFKEELDKYFKNHT-1160, P144), which could be recognized by pre-existing antibodies in both human and mouse. Through metagenomic sequencing and fecal bacteria transplant, we proved that the generation of S2 cross-reactive antibodies was associated with commensal gut bacteria. Furthermore, six P144 specific monoclonal antibodies were isolated from naive SPF mice and proved to cross-react with commensal gut bacteria collected from both human and mouse. Mice with high levels of pre-existing S2 cross-reactive antibodies mounted higher S protein specific binding antibodies, especially against S2, after being immunized with a SARS-CoV-2 S DNA vaccine. Similarly, we found that levels of pre-existing S2 and P144 reactive antibodies correlated positively with RBD specific binding antibody titers after two doses of inactivated SARS-CoV-2 vaccination in human. Finally, we provided data demonstrating that immunization of a SARS-CoV-2 S DNA vaccine could alter the gut microbiota compositions of mice.

Developed the clinical nursing information system effectiveness evaluation scale based on the new D&M model and conducted reliability and validity evaluation / 中国实用护理杂志

Objective:To develop a nursing information system effectiveness evaluation scale based on the new D&M model and verify its reliability and validity.Methods:Six dimensions of the scale were constructed based on the framework of the new D&M model,through the methods including literature reading,expert discussion to determine the specific indicators of the questionnaire, and then forming the initial questionnaire. The dimensions and items of the test scale were modified by discriminant analysis method, correlation coefficient analysis method and Cronbach's αcoefficient method. The construct validity of the scale was analyzed by exploratory factor analysis method, and the dimensions and items of the test scale were optimized. Internal consistency and retest reliability were used to analyze the reliability of the scale.Results:Five common factors were extracted by exploratory factor analysis to explain the total variation of 57.462%. The final version of the scale consists of 5 dimensions and 23 items. The total Cronbachα coefficient of the scale was 0.768, and the total correlation coefficient was 0.849.Conclusions:The 5 dimensions retained by the scale have good construction validity, which can effectively explain the psychological characteristics of the subjects, and the results measured by the scale have good stability and consistency. This scale can be used to evaluate the effectiveness of nursing information system.

Research Progress in Escape Mutations of the Human Immunodeficiency Virus under Pressure of HLA-Restricted Cytotoxic T Lymphocytes / 病毒学报

Human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T lymphocytes (CTLs) play a critical role in the control of HIV-1 infection and replication. HIV-1 evades CTL mediated pressure through viral escape mutations within targeted CTLs epitopes or flanking regions, but this process is usually associated with a viral fitness cost. The mutated epitopes may weaken the level of the original CTL responses, however, the immune system holds potential to mount denovo responses towards those newly emerged epitopes. This article briefly summarizes recent research progress regarding the competition between HIV-1's escape mutations and host CTL responses.

Epitope competition weakens specific T cell response to subdominant epitopes / 中华微生物学和免疫学杂志

Objective To elucidate the influences of epitope competition on the frequency and average intensity of specific T cell response.Methods C57BL/6 mice were immunized with either single epitope DNA vaccines (pSV-gag92 or pSV-env203) or fusion gene DNA vaccine (pSV-gag/env).Gag92and Env203 epitope-specific CD8 T cell responses were analyzed by intracellular cytokine staining assay.Results Gag92-specific IFN-γ+CD8 T cells that were induced by pSV-gag92 accounted for 0.415 00％ ±0.045 88％ of the total CD8 T cells,which was much more than that induced by pSV-gag/env of 0.058 67％ + 0.019 64％.Moreover,the mean fluorescence intensity of Gag92-specific TNF-α-IFN-γ+CD8 T cells (296.70+14.08) elicited by pSV-gag/env was significantly lower than that of Env203-specific TNF-α-IFN-γ+CD8 T cells (818.00+49.34).Conclusion Epitope competition could significantly decrease both the frequency and the average intensity of specific T cell response to subdominant epitopes.

Cross-genome HIV-specific cytotoxic T-lymphocyte responses among HIV-1 infected individuals with varied infection time and routes / 中华检验医学杂志

Objective To investigate and compare the features of the HIV-1-specific CTL responses among three HIV-infected groups with varied infection history. Methods Three HIV-infeeted groups were enrolled in this study, including two groups infected by blood transmission (one group has been infected for more than 10 years and the other for 1-2 years) and one group of the man who have sex with man. The HIV-1-specific CTL responses were quantified by an IFN-γ based ELISPot assay with a peptide matrix system containing overlapping peptides spanning the entire HIV-1 Clade B genomic consensus sequences. Results The responding rate of CTL responses against all 17 peptide pools among the group that infected 1-2 years,the group infected more than 10 years and the group of MSM were 40% ,65% ,23%. One way ANOVO analysis showed that the responding rate of CTL responses against all 17 peptide pools were statistical significant among the three groups (F=19.96, P＜0.01);the magnitude of CTL responses of the three groups were 0-5 835 SFCs/106 PBMC, 0-7 225 SFCs/106PBMC, 0-9 740SFCs/106pBMC, Kruskal-Wallis test showed that the magnitude of CTL responses were statistical significant among the three groups( H = 101.90 , P ＜0.01);the breadth of CTL were 7 ( 2-11 ), 11(9-14) and 4 (2-6) respectively and Kruskal- Wallis test showed that the breadth of CTL had no statistical significant among the three groups( H = 34. 75 ,P ＜0. 01 ). The sequence of responding rate, magnitude and breadth of CTL from high to low was the group that had been infected for more than 10 years, the group infected 1-2 years and the sex transmission group. The common characteristics of the CTL response among the three groups were that the responding rate and the magnitude of the peptide Nef and Gag was higher than other peptide's. The magnitude of CTL responses among three different CD4count groups (CD4 ＜ 200/μl, CD4 200-500/μl, CD4 ≥500/μl,) was 0-18 475 SFCs/106pBMC, 350-34 095 SFCs/106pBMC, 490-21 550 SFCs/106 PBMC and had no statistic difference among the three different CD4 groups(H=2.93, P=0.23) while the breadth of CTL was 3(0-8), 10(2-17), 10 (1-17)respoctively and the breadth of CTL was lower in the group of CD4 count less than 200/μl than the other two groups( H = 14. 72, P ＜ 0. 01 ). The magnitude of CTL responses among three different viral load (VL)groups (VL＜ LDL, LDL ＜ VL ＜ 1 × 104 copys/ml, VL≥1 ×104 copys/ml) was 490-18 475 SFCs/106pBMC, 0-24 115 SFCs/106pBMC, 770-34 095 SFCs/106 pBMC and had no statistic difference among the three different viral load groups ( H = 0.79, P=0.67) and the breadth of the three different viral load groups CTL was 8( 1-17), 11 (0-17), 8 (1-16) and Kruskal-Wallis test showed that there was no statistic difference among the three different viral load groups (H =5.27, P =0. 07). Conclusions All groups predominantly develope T cell immune responses against Nef and Gag proteins. With the elapse of HIV infection, the CTL responses are increased in both magnitude and responding rate. This information is important for vaccine development.

Immunogenicity of DNA vaccines encoding regulatory/accessory proteins derived from three different prevalent strains in China / 中华微生物学和免疫学杂志

0bjective To determine the immunogenicities of DNA vaccines expressing tat-rev-integrase(c-half)-vif-neffusion genes(TRIVN) derived from prevalent B', B'/C and AE recombinant subtypes of HIV-1 in China. Methods Two DNA vaccines were constructed by inserting the codon optimized tat-revintegrase(c-half)-vif-nef fusion genes derived from B' and B'/C subtype of HIV-1 into mammalian expression vector pSVI. 0. DNA vaccine containing tat-rev-integrase (c-half)-vif-nef fusion gene derived from HIV-1AE2f has been constructed previously. In vitro expression efficiencies of three DNA vaccines were determined by Western blot and their immunogenicities were compared by immunizing female BALB/c mice. IFN-γ ELISPOT assay was used to read out the specific T cell immunity. Results The constructed DNA vaccines were validated by restriction enzyme digestion and DNA sequencing. Western blot assay showed three constructed DNA vaccines could be expressed at a comparable level in vitro. After vaccination, AE-TRIVN mounted T cell immune responses at (948.0 ± 330.0) SFCs/106 splenocytes, followed by the mixed DNA vaccine[ (500.0 ± 155.0) SFCs/106 splenocytes ], RL-TRIVN r[ ( 195. 1 ± 44.0) SFCs/106 splenocytes ]and CN-TRIVN [ (89.5 ± 17.0) SFCs/106 splenocytes]. Interestingly, we observed that single DNA vaccination induced specific T cell responses predominantly targeting Integrase (C-half) and Vif, whereas the mixed DNA could significantly improve T cell responses against Nef. Conclusion AE-TRIVN was the most immunogenic among the three DNA vaccines and the mixed DNA vaccination could change the immunogenic hierarchy of T cell epitopes across the fusion genes vaccine.

Immunogenicity of DNA vaccines encoding structural proteins and regulatory/accessory proteins derived from an HIV-1 CRF01_AE isolate circulating in China / 中华微生物学和免疫学杂志

Objective To construct two DNA vaccines encoding Gag-Env fusion protein and Tat-Rev-Integrase(C-half)-Vif-Nef fusion protein derived from the first HIV-1 CRF01_AE isolate(AE2f) in Chi-na and to evaluate the immunogenicity in mice. Methods Two DNA vaccines were constructed by inserting the codon optimized and synthesized gag-env fusion gene and tat-rev-integrase(c-half)-vif-nef fusion gene de-rived from AE2f into mammalian expression vector pDRVISV1. 0, the generated DNA vaccines were desig-nated as pSVAE/GE and pSVAE/TRIVN, respectively, and their in vitro expression were determined by Western blot with transfected 293T cells. Mice were i. m. immunized with either pDRVI1.0 as mock control, pSVAE/GE or pSYAE/TRIVN for 4 times at two-week interval. Two weeks following the final im-munization, cellular responses to pool of HIV-1 Env, Gag, Tat, Rev, Intergrase, Vif and Nef peptides were evaluated by ELISPOT assay. Results The construction of DNA vaccine pSVAE/GE and pSVAE/TRIVN was validated by restriction enzyme digestion and bidirectional sequencing. Western blot showed a specific band at molecular mass 220×10~3 in lane of pSVAE/GE transfeeted 293T cell and a specific band at 95×10~3 in the lane of pSVAE/TRIVN. Both DNA vaccines mounted significant specific T cell responses with (3010 ± 566) SFC/10~6 splenocytes for DNA vaccine pSV AE/GE and (948 ± 737) SFC/10~6 spleno-cytes for DNA vaccine pSVAE/TRIVN, whereas the mock control of pDRVISV1.0 only raised marginal T cell responses. Conclusion Both pSVAE/GE and pSVAE/TRIVN were capable of expressing the inserted fusion immunogen genes and able to elicit vigorous cellular immune responses, therefore, these DNA vac-cines are highly immunogenic.