Monovalent SARS-COV-2 mRNA vaccine using optimal UTRs and LNPs is highly immunogenic and broadly protective against Omicron variants

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 120; no. 52; p. e2311752120
• Main Authors: Ye, Zhongfeng, Bonam, Srinivasa Reddy, McKay, Lindsay G A, Plante, Jessica A, Walker, Jordyn, Zhao, Yu, Huang, Changfeng, Chen, Jinjin, Xu, Chutian, Li, Yamin, Liu, Lihan, Harmon, Joseph, Gao, Shuliang, Song, Donghui, Zhang, Zhibo, Plante, Kenneth S, Griffiths, Anthony, Chen, Jianzhu, Hu, Haitao, Xu, Qiaobing
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 26.12.2023
• Subjects: 3' Untranslated Regions; Animals; Antibodies, Neutralizing; Antibodies, Viral; Antigenic drift; Antigens; Carboxylesterase; CD4 antigen; CD8 antigen; Coronaviruses; COVID-19; COVID-19 - prevention & control; COVID-19 vaccines; COVID-19 Vaccines - genetics; Cricetinae; Cross-protection; Hamsters; Humans; Immune response; Immune response (humoral); Immune system; Immunogenicity; Immunological memory; Lipids; Lungs; Lymphocytes; Lymphocytes T; Memory cells; Mice; mRNA; mRNA Vaccines; Nanoparticles; Respiratory diseases; RNA, Messenger - genetics; Robust control; SARS-CoV-2 - genetics; Severe acute respiratory syndrome coronavirus 2; Vaccines; Viral diseases; untranslated region; lipid nanoparticle; lung tissue-resident memory T cells; mRNA vaccine
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2311752120

The emergence of highly transmissible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) that are resistant to the current COVID-19 vaccines highlights the need for continued development of broadly protective vaccines for the future. Here, we developed two messenger RNA (mRNA)-lipid nanoparticle (LNP) vaccines, TU88mCSA and ALCmCSA, using the ancestral SARS-CoV-2 spike sequence, optimized 5' and 3' untranslated regions (UTRs), and LNP combinations. Our data showed that these nanocomplexes effectively activate CD4 and CD8 T cell responses and humoral immune response and provide complete protection against WA1/2020, Omicron BA.1 and BQ.1 infection in hamsters. Critically, in Omicron BQ.1 challenge hamster models, TU88mCSA and ALCmCSA not only induced robust control of virus load in the lungs but also enhanced protective efficacy in the upper respiratory airways. Antigen-specific immune analysis in mice revealed that the observed cross-protection is associated with superior UTRs [Carboxylesterase 1d (Ces1d)/adaptor protein-3β (AP3B1)] and LNP formulations that elicit robust lung tissue-resident memory T cells. Strong protective effects of TU88mCSA or ALCmCSA against both WA1/2020 and VOCs suggest that this mRNA-LNP combination can be a broadly protective vaccine platform in which mRNA cargo uses the ancestral antigen sequence regardless of the antigenic drift. This approach could be rapidly adapted for clinical use and timely deployment of vaccines against emerging and reemerging VOCs.