Kinetics of adaptive immune responses after administering mRNA-Based COVID-19 vaccination in individuals with and without prior SARS-CoV-2 infections
Sun‐Woo Yoon, Kristin Widyasari, Jieun Jang, Seung Jun Lee, Taejoon Kang, Sun‐Joo Kim
Abstract
Abstract Objective We aimed to compare the adaptive immune response in individuals with or without prior SARS-CoV-2 infections following the administration of mRNA-based COVID-19 vaccines. Methods A total of 54 participants with ages ranging from 37 to 56 years old, consisting of 23 individuals without a history of SARS-CoV-2 infection (uninfected group) and 31 individuals with prior infection of SARS-CoV-2 (infected group) who have received two doses of mRNA SARS-CoV-2 vaccines were enrolled in this study. We measured the IFN-γ level upon administration of BNT162b2 (PF) or mRNA-1273 (MO) by QuantiFERON SARS-CoV-2. The production of neutralizing antibodies was evaluated by a surrogate virus neutralization assay, and the neutralizing capacity was assessed by a plaque reduction neutralization test (PRNT 50 ). The immune response was compared between the two groups. Results A significantly higher level of IFN-γ (p < 0.001) and neutralization antibodies (p < 0.001) were observed in the infected group than those in the uninfected group following the first administration of vaccines. The infected group demonstrated a significantly higher PRNT 50 titer than the uninfected group against the Wuhan strain (p < 0.0001). Still, the two groups were not significantly different against Delta (p = 0.07) and Omicron (p = 0.14) variants. Following the second vaccine dose, T- and B-cell levels were not significantly increased in the infected group. Conclusion A single dose of mRNA-based COVID-19 vaccines would boost immune responses in individuals who had previously contracted SARS-CoV-2.