Heterologous ChAdOx1-BNT162b2 vaccination in a Korean cohort induces a robust genetic immune and antibody response that includes Omicron

Published: 16 May 2022| Version 1 | DOI: 10.17632/j7pbc5ytgd.1
Hye Kyung Lee


Heterologous ChAdOx1-BNT162b2 vaccination induces a stronger immune response than two doses of BNT162b2. Yet, the molecular transcriptome, the germline allelic variants of immunoglobulin loci and anti-Omicron antibody levels induced by the heterologous vaccination have not been formally investigated. Moreover, there is a paucity of COVID-19 vaccine studies including diverse genetic populations. Here, we show a robust molecular immune transcriptome and antibody repertoire in 46 office and lab workers from the Republic of Korea after heterologous vaccination, ChAdOx1 followed by BNT162b2. Anti-spike-specific IgG antibody levels against the ancestral SARS-CoV-2 strain increased from 70 AU/ml immediately following the first vaccination to 14,000 U/ml within three days after the second vaccination and 142,000 AU/ml after seven days. Antibody titers against more recent variants, including Omicron, were two- to three-fold lower, yet higher than those obtained after the second dose of a BNT162b2-BNT162b2 homologous vaccination. RNA-seq conducted on peripheral immune cells demonstrated a strong activation of interferon-induced genetic programs in the heterologous cohort and an increase of specific IGHV clonal transcripts encoding neutralizing antibodies was detected. Enrichment of B cell and CD4+ T cell responses was observed following both ChAdOx1-BNT162b2 heterologous and BNT162b2-BNT162b2 homologous vaccination using scRNA-seq, but clonally expanded memory B cells were relatively stronger in the heterologous cohort. In summary, a heterologous vaccination with ChAdOx1 followed by BNT162b2 provides an innate and adaptive immune response exceeding that seen in homologous BNT162b2 vaccination.



National Institutes of Health


RNA Sequencing, Immunoglobulin Gene, Neutralizing Antibody, Antiviral Antibody, Study Participant, Vaccination, COVID-19