Comparison of the Immunogenicity and Protective Efficacy of Various SARS-CoV-2 Vaccines among Healthcare Workers: Are Our White Coat Armies Protected?

Abstract

Background: The effective immunization of healthcare workers (HCWs) plays a vital role in preventing the spread of SARS-CoV-2 infection during the coronavirus disease 2019 (COVID-19) pandemic. There is limited data on the immune response to vaccination among HCWs. We aim to determine seroprevalence rates and neutralizing IgG antibody response to various immunizations among HCWs. Methods: This study was conducted between July and September 2021, in which blood samples were obtained from HCWs and SARS-CoV-2 IgG neutralizing antibodies were measured. Data regarding vaccination status with Pfizer/BioNTech, Sinopharm, or AstraZeneca vaccines, occupation, and prior COVID-19 infection were analyzed. Results: COVID-19 infection post-vaccination was associated with higher mean antibody titers, regardless of vaccine type. Pfizer/BioNTech vaccination produced higher mean antibody titers for HCWs with prior COVID-19 infection (p < 0.00001) than other types of vaccines. Although 96% of HCWs were vaccinated, 3% were seronegative. For HCWs who were seropositive, there were no significant differences between the mean antibody titers when comparing occupations and blood indices. Conclusion: Awareness of the immunity status of HCWs is key to protecting this important group against SARS-CoV-2, especially those without prior COVID-19 infection. Further public health efforts regarding booster vaccination for HCWs are crucial to provide necessary antibody protection.

COVID-19 Antibody Seroconversion in Cancer Patients: Impact of Therapy Cessation—A Single-Center Study

“…However, our data showed no significant difference in seroconversion rates between T1 and T2 in either of the vaccinated groups, consistent with the findings of Wheeler et al study in their study of healthy individuals [31]. When the number of seroconverted patients at T0 and T1 was evaluated, our data revealed that BNT162b2 vaccinated patients had a considerably higher seroconversion rate between T0 and T1, which is consistent with earlier studies in healthy adults [32][33][34]. BBIBP-CorV vaccinated group, on the other hand, demonstrated an insignificant distinction between T0 and T1 seroconversion rates, similar to a study conducted in a healthy population by Zhang et al [35], which indicates that the BBIBP-CorV vaccine requires a second dose or a booster vaccine dose to enhance the humoral immune response in cancer patients, as in healthy individuals.…”

Evaluation of Seroconversion Rate Following SARS COV 2 Vaccination in Health Care Workers at Shahid Beheshti University of Medical Sciences

“…This difference in the amount was more remarkable for people from this study who received two doses of the AstraZeneca vaccine than those who received two doses of the Sinopharm and Sputnik vaccines. A study showed that the history of corona disease significantly affected neutralizing antibody titer and IgG antibody titer in both types of AstraZeneca and Sinopharm vaccines 27 .…”