Akademik Veri Yönetim Sistemi
33rd International Congress of Antimicrobial Chemotherapy, İstanbul, Türkiye, 3 - 06 Kasım 2024
Aim
We aimed to test the cross-neutralizing antibody response of hospital health-care workers (HCWs) vaccinated with CoronaVac and/or BioNTech against SARS-CoV-2 Omicron variant that appeared in February 2024 in Turkey.
Background
HCWs are at risk for exposure to many viruses because of their contact with infectious patients. As SARS-CoV-2 Omicron and its subvariants are increasing in prevalence worldwide, HCWs are still dealing with it.
Methods
SARS-CoV-2 isolates, collected from the nasopharyngeal samples of COVID-19 patients, were propagated in Vero-E6 cells and the viral titration was carried out by PFU/mL, TCID50/mL assays, and RT-qPCR. The whole genome of variants was sequenced. We tested the protectivity of 102 serum samples of HCWs, collected between September and October 2023, through serum neutralization experiments. Viral RNA loads in the cell culture supernatants after infection were calculated by RT-qPCR. Furthermore, anti-SARS-CoV-2 antibodies (IgG) were screened by ELISA. The results were compared with the data of the Omicron variant, isolated in 2021 and used as a control group.
Results
The delta(Ct) values of RT-qPCR results of the new variant were found to be statistically lower than those of control variant (9.36±1.28 vs. 11.82±1.72, p<0.001). In addition, there is a moderate positive significant correlation between the number of vaccine doses and ELISA results (r=0.343, p=0.001).
Conclusions
The vaccine provides dose-dependent positive protection against SARS-CoV-2 and HCWs were more vulnerable to the new Omicron variant. As the pandemic is over, widespread use of infection control precautions rather than vaccination will be protective for HCWs against the virus.