Broad humoral and cellular immunity elicited by one-dose mRNA vaccination 18 months after SARS-CoV-2 infection
Authors
Chang Kyung Kang ; Hyun Mu Shin ; Pyoeng Gyun Choe ; Jiyoung Park ; Jisu Hong ; Jung Seon Seo ; Yung Hie Lee ; Euijin Chang ; Nam Joong Kim ; Minji Kim ; Yong-Woo Kim ; Hang-Rae Kim ; Chang-Han Lee ; Jun-Young Seo ; Wan Beom Park ; Myoung-Don Oh
Background: Practical guidance is needed regarding the vaccination of coronavirus disease 2019 (COVID-19) convalescent individuals in resource-limited countries. It includes the number of vaccine doses that should be given to unvaccinated patients who experienced COVID-19 early in the pandemic.
Methods: We recruited COVID-19 convalescent individuals who received one or two doses of an mRNA vaccine within 6 or around 18 months after a diagnosis of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Their samples were assessed for IgG-binding or neutralizing activity and cell-mediated immune responses against SARS-CoV-2 wild-type and variants of concern.
Results: A total of 43 COVID-19 convalescent individuals were analyzed in the present study. The results showed that humoral and cellular immune responses against SARS-CoV-2 wild-type and variants of concern, including the Omicron variant, were comparable among patients vaccinated within 6 versus around 18 months. A second dose of vaccine did not significantly increase immune responses.
Conclusion: One dose of mRNA vaccine should be considered sufficient to elicit a broad immune response even around 18 months after a COVID-19 diagnosis.