Author:
Nithichanon Arnone,Kamuthachad Ludthawun,Salao Kanin,Phoksawat Wisitsak,Kamsom Chatcharin,Wongratanacheewin Surasakdi,Pipattanaboon Chonlatip,Kanthawong Sakawrat,Yordpratum Umaporn,Aromseree Sirinart,Meesing Atibordee,Mootsikapun Piroon,Edwards Steven W.,Phanthanawiboon Supranee
Abstract
AbstractSeveral vaccine programs were introduced during the COVID-19 pandemic, which included inactivated virus, DNA viral vectors and mRNA vaccines. Booster programs are recommended, especially for those in high-risk groups. However, many of these booster programs involve heterologous vaccines. This study enrolled volunteers who first received two full-dose CoronaVac vaccinations before receiving heterologous boosters with DNA- and/or mRNA-vaccines for an additional 2 doses (n = 40) or an additional 3 doses (n = 16). Our results showed no difference in side effects, neutralizing antibodies, or T-cell responses for any of the heterologous vaccination programs. However, the neutralizing capacity and IFN-γ responses against the Omicron variant in volunteers who received 4 or 5 doses were improved. Polarization of peripheral memory T cells after stimulation in all booster groups with Omicron peptide showed an increased trend of naïve and central memory phenotypes of both CD4+ and CD8+ T cells, suggesting that exposure to Omicron antigens will drive T cells into a lymphoid resident T cell phenotype. Our data support a continuous vaccination program to maximize the effectiveness of immunity, especially in people at high risk. Furthermore, the number of boosting doses is important for maintaining immunity.
Funder
the Program Management Unit Competitiveness (PMUC) under Thailand Science Research and Innovation
the Basic Research Fund of Khon Kaen University, Thailand
Publisher
Springer Science and Business Media LLC