Viral Load in of Patients Vaccinated with Various Vaccination Schemes

• Published in: SN comprehensive clinical medicine 2023-06, Vol.5 (1), Article 171
• Main Authors: Bayhan, Gülsüm İclal, Şahiner, Enes Seyda, Özkubat Korkmaz, Irmak, Göv, Muhammet, Akdağ, Ahmet Gökhan, Yahsi, Aysun, Uyan Erten, Ayşegül Zehra, Demir Gürdal, Merve Feyza, Kırca, Fisun, Dinç, Bedia, Ateş, İhsan
• Format: Article
• Language: English
• Subjects: Medicine; Medicine & Public Health; Original Paper; Topical Collection on COVID-19
• ISSN: 2523-8973; 2523-8973
• DOI: 10.1007/s42399-023-01511-2

It is still unclear how the SARS-CoV-2 viral loads in breakthrough infections that develop in individuals vaccinated with COVID-19. Recent studies have reported different results regarding breakthrough infections’ SARS-CoV-2 viral loads when compared to unvaccinated cases. This study aimed to analyze the viral loads of the partially vaccinated, fully vaccinated and boostered subjects vaccinated with different vaccine protocols including the CoronaVac vaccine, by comparing the Ct values. The data of laboratory-confirmed SARS-CoV-2 patients were analyzed in this study where the Ct values in those of unvaccinated fully, vaccinated with two doses of CoronaVac or two doses of BioNTech, partially vaccinated with one dose of CoronaVac or one dose of BioNTech or boosted with CoronaVac or BioNTech were compared. Based on the time elapsed after vaccination, Ct values at 15–90 days, 91–150 days, 151–210 days, and > 211 days were evaluated. A total of 2643 patients, 1839 of whom were vaccinated and 804 were unvaccinated, were included. Among these groups, the Ct value at 15–90 days in group who had a dose of BionTech booster after 2 doses of CoronaVac was significantly higher Ct value at 91–150 days in group who had two doses of CoronaVac ( p  = 0.021). No other statistically significant difference was found between the groups. In conclusion, fully vaccinated or boosted with CoronaVac or BioNTech vaccine does not reduce the viral load in breakthrough infections.