Immunogenicity profiling and distinct immune response in liver transplant recipients vaccinated with SARS-CoV-2 inactivated vaccines.

SARS-CoV-2 vaccination has been recommended for liver transplant (LT) recipients. However, our understanding of inactivated vaccine stimulation of the immune system in regulating humoral and cellular immunity among LT recipients is inadequate. Forty-six LT recipients who received two-dose inactivated vaccines according to the national vaccination schedule were enrolled. The clinical characteristics, antibody responses, single-cell peripheral immune profiling, and plasma cytokine/chemokine/growth factor levels were recorded. Sixteen (34.78%) LT recipients with positive neutralizing antibody (nAb) were present in the Type 1 group. Fourteen and 16 LT recipients with undetected nAb were present in the Type 2 and Type 3 groups, respectively. Time from transplant and lymphocyte count were different among the three groups. The levels of anti-RBD and anti-S1S2 decreased with decreasing neutralizing inhibition rates. Compared to the Type 2 and Type 3 groups, the Type 1 group had an enhanced innate immune response. The proportions of B, DNT, and CD3+CD19+ cells were increased in the Type 1 group, whereas monocytes and CD4+ T cells were decreased. High CD19, high CD8+CD45RA+ cells, and low effector memory CD4+/naïve CD4+ cells of the T-cell populations were present in the Type 1 group. The Type 1 group had higher concentrations of plasma CXCL10, MIP-1 beta, and TNF-alpha. No severe adverse events were reported in all LT recipients. We identified the immune responses induced by inactivated vaccines among LT recipients and provided insights into the identification of immunotypes associated with the responders.

Effectiveness of the ChAdOx1 nCoV-19 Coronavirus Vaccine (CovishieldTM) in Preventing SARS-CoV2 Infection, Chennai, Tamil Nadu, India, 2021.

We estimated the effectiveness of two doses of the ChAdOx1 nCoV-19 (Covishield) vaccine against any COVID-19 infection among individuals ≥45 years in Chennai, Tamil Nadu, India. A community-based cohort study was conducted from May to September 2021 in a selected geographic area in Chennai. The estimated sample size was 10,232. We enrolled 69,435 individuals, of which 21,793 were above 45 years. Two-dose coverage of Covishield in the 18+ and 45+ age group was 18% and 31%, respectively. Genomic analysis of 74 out of the 90 aliquots collected from the 303 COVID-19-positive individuals in the 45+ age group showed delta variants and their sub-lineages. The vaccine's effectiveness against COVID-19 disease in the ≥45 age group was 61.3% (95% CI: 43.6-73.4) at least 2 weeks after receiving the second dose of Covishield. We demonstrated the effectiveness of two doses of the ChAdOx1 vaccine against the delta variant in the general population of Chennai. We recommend similar future studies considering emerging variants and newer vaccines. Two-dose vaccine coverage could be ensured to protect against COVID-19 infection.

Attitudes of family medicine residents in Ankara towards COVID-19 vaccines administered in Turkey: a descriptive, cross-sectional study

Background. The difficulty of accessing accurate information during the COVID-19 pandemic resulted in many questions being asked to family physicians about vaccination. Objectives. The aim of this study was to determine the attitudes of Family Medicine (FM) residents in Ankara about the inactivated and mRNA COVID-19 vaccines being administered in Turkey. Material and methods. An anonymous online survey was distributed to FM residents between 22.05.2021–06.06.2021. Information on socio-demographic data and residents’ attitudes towards COVID-19 vaccines administered in Turkey were evaluated. Results. 11.1% of the participants were not vaccinated for the following reasons: having positive Anti-Spike antibody values, think-ing that there had not been enough studies on vaccines, vaccine safety concerns, belief that innate immunity would be more pro-tective, pregnancy, breastfeeding or not believing in the protection of the vaccine. While 12.2% of the participants recommended Sinovac-CoronaVac, 23.7% recommended Pfizer/BioNTech, and 63.3% stated that they would evaluate the patient and make recom-mendations. Most of the participants stated that they thought the Pfizer/BioNTech is more protective against new variants (70.4%), more effective and produces a higher antibody response (84.2%) and provides longer-term protection (74.8%). However, 74.1% of the participants stated that they thought Sinovac-CoronaVac is safer. Sinovac-CoronaVac was recommended to patients with a history of allergic reaction/anaphylaxis (69.8%), autoimmune diseases (60.4%), oncology/chemotherapy patients (49.6%), immunosuppressed patients (49.6) and lactating women (44.6%). Conclusions. In some case-basis recommendations, it was seen that the residents showed a traditionalist approach. Informing individuals based on scientific information on the safety and effectiveness of the COVID-19 vaccines by family physicians is crucial. © by Wydawnictwo Continuo.

Safety and immunogenicity of a third-dose homologous BBIBP-CorV boosting vaccination: interim results from a prospective open-label study.

A COVID-19 booster vaccination is being comprehensively evaluated globally due to the emerging concern of reduced protection rate of previous vaccination and circulating Variants of Concern (VOC). But the safety and immunogenicity of homologous BBIBP-CorV boosting vaccination are yet to be thoroughly evaluated. We conducted this prospective, open-label study in Huashan Hospital using a third 6.5U BBIBP-CorV administered at an interval of 4-8 months following the previous two doses in healthy adults. Safety, anti-RBD response and neutralizing titers against SARS-CoV-2 and VOCs were examined. Sixty-three and forty participants entered the booster and the control group, respectively. A significant increase in IFN-γ SFU per million PBMCs was observed on day 14 against N peptide (20 vs. 5, P < 0.001). On day 14, pVNT GMTs increased over 15 folds of the baseline levels against prototype to reach 404.54 titers and over 9-13 folds against 4 VOCs and continuously increased by day 28. sVNT GMTs increased 112.51 and 127.45 folds by days 14 and 28 compared to the baseline level. Median anti-RBD antibody and IgG level significantly increased from 11.12 to 2607.50 BAU/ml and 4.07 to 619.20 BAU/ml on day 14. On day 14, females showed a significantly higher cell-mediated immune response against S1 peptide. The 7-8 months interval group had a higher humoral response than the 4-6 months interval group. No severe adverse event was reported. A third homologous BBIBP-CorV boosting vaccination was safe and highly immunogenic for healthy adults and broadened participants' immunity against VOCs.