A real-world study on the effectiveness of BBIBP-CorV and CoronaVac in Nanjing area.

Since the advent of COVID-19 vaccine, the long-term monitoring and evaluation of vaccine effectiveness worldwide has never stopped. Real-world research of the mainstream vaccines in China (BBIBP-CorV and CoronaVac) is extremely valuable as a supplement to clinical research data. Venous blood of this study was collected from 111 blood donors and from 6 volunteers, who had received 2 doses of SAR-CoV-2 vaccine. Cross-sectional study and cohort study was adopted. Venous blood of 11 COVID-19 convalescent plasma donors was collected as a positive control. The seroconversion rate of neutralizing antibodies in 111 vaccine recipients was 90.99% (101/111); The level of SAR-CoV-2 antibodies peaked around 28 days after inoculation, then fast descended followed by gentle descended until it was still detectable around 280 days later. The changes in antibody levels were similar to those of the 6 participants and those of convalescent plasma donors after infection. 5 of the 6 participants still maintained a high level of neutralizing antibodies (> 60% of the peak value) around 28 days after receiving 2 doses of vaccine; one participant had an antibody reaction that was almost always negative for 4 weeks. BBIBP-CorV and CoronaVac can produce good immune effects in most vaccinators aged 20 to 59 years in Nanjing area. Nevertheless, significant individual discrepancies of the humoral immunity are still existed.

ABO blood group influence COVID-19 infection: a meta-analysis.

INTRODUCTION: Previous studies have linked the relationship between ABO blood group and COVID-19 infection. However, existing evidence is preliminary and controversial. This meta-analysis sought to identify studies that describe COVID-19 and ABO blood group. METHODOLOGY: A literature search was conducted from PubMed, Web of Science, MedRxiv, BioRxiv and Google Scholar databases. Members of cases and controls were extracted from collected studies. Pooled Odds ratio (OR) and 95% confidence interval (95%CI) were calculated and interpreted from extracted data. Publication bias and sensitivity analysis were also applied to confirm our discovery. RESULTS: Total 13,600 patients and 3,445,047 controls were included in the study. Compared to other ABO blood group, blood group O was associated with a lower risk of COVID-19 infection (OR = 0.76, 95%CI 0.66-0.84), while blood group A and AB was associated with a higher risk (OR = 1.25, 95%CI 1.10-1.41; OR = 1.13, 95%CI 1.04-1.23, respectively). In the subgroup analysis, the relationship between blood group A, O and COVID-19 infection remained stable among Chinese, European and Eastern Mediterranean populations. In American population, blood groups B was linked with increased risk of COVID-19 infection (OR = 1.21, 95%CI 1.09-1.35). CONCLUSIONS: Our data suggested that individuals with blood types A and AB are more susceptible to COVID-19, while people with blood type O are less susceptible to infection. More research is needed to clarify the precise role of the ABO blood group in COVID-19 infection to address the global question.