Systemic COVID-19 vaccination also enhances the humoral immune response after SARS CoV-2 infection in the population of an oncology hospital in Poland. Criteria for COVID-19 re-immunization are needed.

Abstract

Systemic vaccination of the BNT162b2 mRNA stimulates humoral response. Our study aimed to compare the intensity of humoral immune response, measured by SARS CoV-2 IgG, SARS CoV-2 IgM, and neutralization S-RBD IgG antibodies level, post COVID-19 vaccination versus post-SARS CoV-2 infection. We analyzed 1060 people in the following groups: convalescents, healthy vaccinated, vaccinated with Comirnaty, AstraZeneca, Moderna, Johnson & Johnson, and vaccinated SARS CoV-2 convalescents. A concentration of SARS CoV-2 IgG, SARS CoV-2 IgM, and neutralizing S-RBD IgG was estimated in the oncology hospital laboratory by chemiluminescent immunoassay - CLIA, MAGLUMI. Results: 1. We observed a rise of antibodies response in both convalescent SARS CoV-2 and COVID-19 vaccinated groups 2. The level of all antibodies' concentrations in vaccinated COVID-19 convalescents was significantly higher. 3. We differentiated asymptomatic SARS CoV-2 convalescents from the control group. Our analysis suggested that it is essential to monitor SARS CoV-2 IgG antibodies concentrations as an indicator of asymptomatic COVID-19 and equivalent to the effectiveness of humoral response in convalescents and vaccinated people. Considering the time-limited effects of post-infection SARS CoV-2 recovery or vaccination, among others physiological half-life, we suggested monitoring IgG antibodies level as a criterium for the next vaccination.