Predictive value of reactogenicity for anti-SARS-CoV-2 antibody response in mRNA-1273 recipients: a multicenter prospective cohort study

Messenger RNA (mRNA) vaccination has been implemented to mitigate the coronavirus disease 2019 pandemic. However, data on antibody kinetics and factors influencing mRNA vaccines’ immunogenicity are limited. We conducted a prospective study on healthy young adults who received two doses of the mRNA-1273 vaccine at 28-day intervals. After each dose, adverse events were prospectively evaluated and blood samples were collected. The correlation between humoral immune response and reactogenicity after vaccination was determined. In 177 participants (19–55 years), the geometric mean titers of the anti-S IgG antibody were 178.07 and 4409.61 U/mL, whereas those of 50% neutralizing titers were 479.95 and 2851.67 U/mL 4 weeks after the first and second doses, respectively. The anti-S IgG antibody titers were not associated with local reactogenicity, but they were significantly higher in participants who experienced systemic adverse events (fever, headache, and muscle pain). Antipyretic use was an independent predictive factor of strong anti-SARS-CoV-2 antibody response after receiving both doses. Systemic reactogenicity after the first dose influenced antibody response after the second dose. mRNA-1273 induced a robust antibody response in healthy young adults. Post-vaccination immunogenicity might be related to systemic reactogenicity. Antipyretic use did not decrease the anti-SARS-CoV-2 antibody response after mRNA-1273 vaccination. Funding: This work was supported by the Korea National Institute of Health, Korea Disease Control and Prevention Agency [2021ER260300].