DNA vaccination induced protective immunity against SARS CoV-2 infection in hamsterss.

• Main Authors: Kit Man Chai (Author), Tsai-Teng Tzeng (Author), Kuan-Yin Shen (Author), Hung-Chun Liao (Author), Jhe-Jhih Lin (Author), Mei-Yu Chen (Author), Guann-Yi Yu (Author), Horng-Yunn Dou (Author), Ching-Len Liao (Author), Hsin-Wei Chen (Author), Shih-Jen Liu (Author)
• Format: Book
• Published: Public Library of Science (PLoS), 2021-05-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

The development of efficient vaccines against COVID-19 is an emergent need for global public health. The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a major target for the COVID-19 vaccine. To quickly respond to the outbreak of the SARS-CoV-2 pandemic, a nucleic acid-based vaccine is a novel option, beyond the traditional inactivated virus vaccine or recombinant protein vaccine. Here, we report a DNA vaccine containing the spike gene for delivery via electroporation. The spike genes of SARS-CoV and SARS-CoV-2 were codon optimized for mammalian cell expression and then cloned into mammalian cell expression vectors, called pSARS-S and pSARS2-S, respectively. Spike protein expression was confirmed by immunoblotting after transient expression in HEK293T cells. After immunization, sera were collected for antigen-specific antibody and neutralizing antibody titer analyses. We found that both pSARS-S and pSARS2-S immunization induced similar levels of antibodies against S2 of SARS-CoV-2. In contrast, only pSARS2-S immunization induced antibodies against the receptor-binding domain of SARS-CoV-2. We further found that pSARS2-S immunization, but not pSARS-S immunization, could induce very high titers of neutralizing antibodies against SARS-CoV-2. We further analyzed SARS-CoV-2 S protein-specific T cell responses and found that the immune responses were biased toward Th1. Importantly, pSARS2-S immunization in hamsters could induce protective immunity against SARS-CoV-2 challenge in vivo. These data suggest that DNA vaccination could be a promising approach for protecting against COVID-19.

Item Description

1935-2727
1935-2735
10.1371/journal.pntd.0009374