Monitoring of SARS-CoV-2 Specific Antibodies after Vaccination
Raquel Guiomar,
Ana João Santos,
Aryse Martins Melo,
Inês Costa,
Rita Matos,
Ana Paula Rodrigues,
Irina Kislaya,
Anabela Santos Silva,
Carla Roque,
Carla Nunes,
Joaquim Aguiar,
Fátima Graça,
Antônio Silva Graça,
Ausenda Machado
Affiliations
Raquel Guiomar
National Reference Laboratory for Influenza and Other Respiratory Viruses, Infectious Diseases Department, National Institute of Health Doutor Ricardo Jorge, 1649-016 Lisbon, Portugal
Ana João Santos
Epidemiology Department, National Institute of Health Doutor Ricardo Jorge, 1649-016 Lisbon, Portugal
Aryse Martins Melo
National Reference Laboratory for Influenza and Other Respiratory Viruses, Infectious Diseases Department, National Institute of Health Doutor Ricardo Jorge, 1649-016 Lisbon, Portugal
Inês Costa
National Reference Laboratory for Influenza and Other Respiratory Viruses, Infectious Diseases Department, National Institute of Health Doutor Ricardo Jorge, 1649-016 Lisbon, Portugal
Rita Matos
Immunology Laboratory for Infectious Diseases, Infectious Diseases Department, National Institute of Health Doutor Ricardo Jorge, 1649-016 Lisbon, Portugal
Ana Paula Rodrigues
Epidemiology Department, National Institute of Health Doutor Ricardo Jorge, 1649-016 Lisbon, Portugal
Irina Kislaya
Epidemiology Department, National Institute of Health Doutor Ricardo Jorge, 1649-016 Lisbon, Portugal
Anabela Santos Silva
COVID-19 Working Group, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal
Carla Roque
Occupational Health Department, National Institute of Health Doutor Ricardo Jorge, 1649-016 Lisbon, Portugal
Carla Nunes
COVID-19 Working Group, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal
Joaquim Aguiar
COVID-19 Working Group, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal
Fátima Graça
COVID-19 Working Group, National Institute of Health Doutor Ricardo Jorge, 4000-055 Porto, Portugal
Antônio Silva Graça
Occupational Health Department, National Institute of Health Doutor Ricardo Jorge, 1649-016 Lisbon, Portugal
Ausenda Machado
Epidemiology Department, National Institute of Health Doutor Ricardo Jorge, 1649-016 Lisbon, Portugal
Vaccination is considered the most important measure to control the COVID-19 pandemic. Extensive follow-up studies with distinct vaccines and populations are able to promote robust and reliable data to better understand the effectiveness of this pharmacologic strategy. In this sense, we present data regarding binding and neutralizing (achieved by surrogate ELISA assay) antibodies throughout time, from vaccinated and previously infected (PI) health care workers (HCW) in Portugal. We analyzed serum samples of 132 HCW, who were vaccinated and with previous SARS-CoV-2 infection. Samples were collected before vaccination (baseline, M1), at second dose vaccine uptake (M2), and 25–70 days (M3) and 150–210 days (M4) after the second dose for vaccinated individuals. The IgG (anti-RBD/S) antibody geometric mean titers found on vaccinated HCW at M2 (GM = 116.1 BAU/mL; CI: 92.3–146.1) were significantly higher than those found on PI HCW at recruitment (M1) (GM = 35.9 BAU/mL; CI:15.4–83.4), and the neutralizing antibodies (nAb) were similar between these groups, of 93.2 UI/mL (95% CI 73.2–118.5) vs. 84.1 UI/mL (95% CI 40.4–155.9), respectively. We detected around 10-fold higher IgG (anti-RBD/S) antibodies titers in M3 when compared with M2, with a slight but significant decrease in titers from 36 days after the second dose vaccine uptake. The increase of nAb titers was correlated with IgG (anti-RBD/S) antibodies titers; however, in contrast to IgG (anti-RBD/S) antibodies titers, we did not detect a decrease in the nAb titer 36 days after a second vaccine dose uptake. At M4, a decrease of 8-fold in binding IgG (anti-RBD/S) and nAb was observed. No significant differences in antibody titers were observed by sex, age or chronic diseases. Our results suggest that IgG (anti-RBD/S) antibodies titers and nAb titers could be correlated, but an ongoing follow up of the cohort is required to better understand this correlation, and the duration of the immune response.
