Persistence of SARS-CoV-2 Antibodies in Vaccinated Health Care Workers Analyzed by Coronavirus Antigen Microarray

Abstract

Recent studies provide conflicting evidence on the persistence of SARS-CoV-2 immunity induced by mRNA vaccines. Here, we aim to quantify the persistence of humoral immunity following vaccination using a coronavirus antigen microarray that includes 10 SARS-CoV-2 antigens. In a prospective longitudinal cohort of 240 healthcare workers, composite SARS-CoV-2 IgG antibody levels did not wane significantly over a 6-month study period. In the subset of the study population previously exposed to SARS-CoV-2 based on seropositivity for nucleocapsid antibodies, higher composite anti-spike IgG levels were measured before the vaccine but no significant difference from unexposed individuals was observed at 6 months. Age, vaccine type, or worker role did not significantly impact composite IgG levels, although non-significant trends towards lower antibody levels in older participants and higher antibody levels with Moderna vaccine were observed at 6 months. A small subset of our cohort were classified as having waning antibody titers at 6 months, and these individuals were less likely to work in patient care roles and more likely to have prior exposure to SARS-CoV-2.

Analysis and comparison of SARS-CoV-2 variant antibodies and neutralizing activity for 6 months after a booster mRNA vaccine in a healthcare worker population

“…Both IgG antibody levels and neutralization have been shown to wane over the course of months following vaccination. 14,16 The booster vaccine dose has been shown to signi cantly increase both IgG antibody levels and neutralization compared to the pre-boost levels. 5,17 Similarly, the booster vaccine dose has been shown to reduce risk of SARS-CoV-2 breakthrough infections.…”

“…For more information regarding the coronavirus antigen microarray, refer to our previous work. 14 This model was found to be 93% sensitive and 98% speci c in correctly classifying 91 PCR-positive cases and 88 pre-pandemic negative control. 15 The model was then used to generate a weighted composite measure of IgG reactivity across antigens, with weights corresponding to each antigen's relative importance in the model.…”

“…In September of 2021, the FDA approved and UCI secured and administered booster shots to all HCWs who wished to be additionally vaccinated. All HCWs working at the UCI Medical Center, located in Orange County CA, who participated in our previous study 14 were invited to receive serological testing by providing serum blood samples via a ngerstick directly before vaccination, 1-2 weeks after vaccination, 2 months, 4 months, and 6 months after booster vaccination. All blood samples were brought to the Institute for Clinical and Translational Science Core Laboratory at the UCI Medical Center.…”

Age- and sex-based changes in spike protein antibody status after SARS-CoV-2 vaccination and effect of past-infection in healthcare workers in Osaka

“…Serologic testing of antibodies specific to SARS-CoV-2 nucleocapsid protein is used as a marker of a previous infection and may aid in surveying asymptomatic infection and assessing past SARS-CoV-2 infection prevalence. In the subset of the study population previously exposed to SARS-CoV-2 based on seropositivity for nucleocapsid antibodies, higher anti-spike IgG levels are already measured before the vaccine but no significant difference in antispike IgG levels from unexposed individuals is observed after vaccination [16]. We could not determine the time when the participants were positive for nucleocapsid protein antibodies at month 7 after vaccination infected SARS-CoV-2.…”

“…Antibody responses after vaccination showed high interindividual variation in levels. Recent studies provide conflicting evidence on the persistence of SARS-CoV-2 immunity induced by mRNA vaccines [15][16][17]. Antibody kinetics showed differences in immunogenicity according to sex, age group, and coexisting conditions [1,3,15,18].…”