Pfizer-BioNTech and Sinopharm: A Comparative Study on Post-Vaccination Antibody Titers

• Published in: Vaccines (Basel) Vol. 9; no. 11; p. 1223
• Main Authors: Alqassieh, Rami, Suleiman, Aiman, Abu-Halaweh, Sami, Santarisi, Abeer, Shatnawi, Omar, Shdaifat, Lara, Tarifi, Amjed, Al-Tamimi, Mohammad, Al-Shudifat, Abdel-Ellah, Alsmadi, Heba, Al Sharqawi, Ahmed, Alnawaiseh, Hadeel, Anasweh, Yara, Domaidah, Farah Abo, Jaber, Haneen Abu, Al-Zarir, Mohammad Rashid, Bsisu, Isam
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 21.10.2021; MDPI
• Subjects: Adaptive immunity; Antibodies; antibody; Antigens; Cardiovascular diseases; Comparative studies; Confidence intervals; Coronaviruses; COVID-19; COVID-19 vaccines; Enzymes; Immunoglobulin G; Immunoglobulins; Pfizer-BioNTech; Phosphatase; Proteins; Regression analysis; Severe acute respiratory syndrome coronavirus 2; Sinopharm; Statistical analysis; titers; vaccine; Vaccines; Viral diseases; United States > US; COVID-19; Pfizer-BioNTech; Sinopharm; vaccine; antibody; titers
• ISSN: 2076-393X; 2076-393X
• DOI: 10.3390/vaccines9111223

COVID-19 (coronavirus disease 2019) vaccines induce immunity through different mechanisms. The aim of this study is to compare the titers of specific antibodies in subjects vaccinated with either the Pfizer-BioNTech COVID-19 vaccine or the Sinopharm vaccine. This prospective observational cohort included Jordanian adults vaccinated with two doses, 21 days apart, of either of the two aforementioned vaccines. Titers were collected 6 weeks after the administration of the second dose. Overall, 288 participants were included, of which 141 were administered the Pfizer-BioNTech vaccine, while 147 were administered the Sinopharm vaccine. Remarkably, 140 (99.3%) of the Pfizer-BioNTech vaccine recipients had positive IgG titers, while 126 (85.7%) of Sinopharm recipients had positive IgG (p < 0.001). The mean titer for IgG among Pfizer-BioNTech recipients was 515.5 ± 1143.5 BAU/mL, compared to 170.0 ± 230.0 BAU/mL among Sinopharm subjects (p < 0.001). Multivariable regression analysis showed that the Pfizer-BioNTech vaccine positively correlated with positive IgG titers (OR: 25.25; 95% CI: 3.25–196.15; p = 0.002), compared with a negative effect of cardiovascular diseases (OR: 0.33; 95% CI: 0.11–0.99; p = 0.48) on IgG titers. In conclusion, fully vaccinated recipients of the Pfizer-BioNTech vaccine had superior quantitative efficiency compared to Sinopharm recipients. A booster dose is supported for Sinopharm recipients, or those with chronic immunosuppressive diseases.