ABSTRACT
Data of 1,290,222 volunteer blood donors, in a 5-year period, was analyzed for prevalence and incidence of syphilis. Subsequent testing of donations positive in Treponema pallidum hemagglutination assay included Venereal Disease Research Laboratory and fluorescent Treponemal antibody absorption. Stepwise logistic regression model was used to identify positive syphilis serology. Prevalence of syphilis was 47 : 100,000, similar in men and women and increased significantly with age (P < 0.001). Native Israelis had the lowest prevalence rate of syphilis (21 : 100,000), while a significantly higher prevalence was found among immigrants from Africa, Eastern Europe, and South America (odds ratios of 19.0, 10.8, and 7.3, resp., P < 0.001 for each). About 33.2% of the seropositive donors had evidence of recent infection, and 66.8% had past infections. Incidence rate reached 8 : 100,000 person-years. Coinfection with HIV, HCV, and HBV was calculated as 8%, 1.88%, and 0.37% for positive donations, respectively. The data support the need to continue screening blood donors in Israel for syphilis and employ preventive measures to populations at risk, in order to improve public health, blood safety, and quality. A subsequent study to assess blood donors' knowledge, attitude, and behavior is planned. In times of global migration this information may be useful to blood services worldwide.
ABSTRACT
Beyond SARS-CoV-2, six more coronaviruses infect humans (hCoVs), four of which cause only mild symptoms (seasonal/common cold hCoVs) 12. Previous exposures to seasonal hCoVs may elicit immunological memory that could benefit the course of SARS-CoV-2 infections 3. While cross-reactive T cells epitopes of SARS-CoV-2 and seasonal hCoVs have been reported in individuals unexposed to SARS-CoV-2 4-6, potential antibody-based cross-reactivity is incompletely understood. Here, we have probed for high resolution antibody binding against all hCoVs represented as 1,539 peptides with a phage-displayed 7 antigen library. We detected broad serum antibody responses against peptides of seasonal hCoVs in up to 75% of individuals. Recovered COVID-19 patients exhibited distinct antibody repertoires targeting variable SARS-CoV-2 epitopes, and could be accurately classified from unexposed individuals (AUC=0.96). Up to 50% of recovered patients also mounted antibody responses against unique epitopes of seasonal hCoV-OC43, that were not detectable in unexposed individuals. These results indicate substantial interindividual variability and antibody cross-reactivity between hCoVs from the direction of SARS-CoV-2 infections towards seasonal hCoVs. Our accurate high throughput assay allows profiling preexisting antibody responses against seasonal hCoVs cost-effectively and could inform on their protective nature against SARS-CoV-2.
ABSTRACT
The emergence of rapidly spreading variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a major challenge to the ability of vaccines and therapeutic antibodies to provide immunity. These variants contain mutations at specific amino acids that might impede vaccine efficacy. BriLife(R) (rVSV-{Delta}G-spike) is a newly developed SARS-CoV-2 vaccine candidate currently in Phase II clinical trials. It is based on a replication competent vesicular stomatitis virus (VSV) platform. rVSV-{Delta}G-spike contains several spontaneously-acquired spike mutations that correspond to SARS-CoV-2 variants mutations. We show that human sera from BriLife(R) vaccinees preserve comparable neutralization titers towards alpha, gamma and delta variants, and show less than 3-fold reduction in neutralization capacity of beta and omicron compared to the original virus. Taken together, we show that human sera from BriLife(R) vaccinees overall maintain neutralizing antibody response against all tested variants. We suggest that BriLife(R) acquired mutations may prove advantageous against future SARS-CoV-2 VOCs.