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Clinical Trial
. 2024 Jan 29;14(1):2373.
doi: 10.1038/s41598-023-49653-6.

Phase II prefusion non-stabilised Covid-19 mRNA vaccine randomised study

Thanyawee Puthanakit #  1   2   3 , Eakachai Prompetchara #  4   5 , Sivaporn Gatechompol  6   7   8 , Chutitorn Ketloy  4   5 , Arunee Thitithanyanont  9 , Anan Jongkaewwattana  10 , Supranee Buranapraditkun  4   11 , Sasiwimol Ubolyam  12   13 , Stephen J Kerr  14   15   16 , Jiratchaya Sophonphan  15 , Tanakorn Apornpong  15 , Wonngarm Kittanamongkolchai  3 , Sarawut Siwamogsatham  3 , Somchai Sriplienchan  17 , Kanitha Patarakul  4   18 , Tuangtip Theerawit  2 , Pathariya Promsena  2   17 , Rapisa Nantanee  1   2 , Siwaporn Manomaisantiphap  19 , Sarun Chokyakorn  19 , Lina Hong  20 , Mijo Samija  20 , David C Montefiori  21 , Hongmei Gao  21 , Amanda Eaton  21 , Wassana Wijagkanalan  22 , Mohamad-Gabriel Alameh  23 , Drew Weissman  23 , Kiat Ruxrungtham  24   25   26 ; ChulaVac001-Phase 2 study team
Collaborators, Affiliations
Clinical Trial

Phase II prefusion non-stabilised Covid-19 mRNA vaccine randomised study

Thanyawee Puthanakit et al. Sci Rep. .

Abstract

ChulaCov19 mRNA vaccine demonstrated promising phase 1 results. Healthy adults aged 18-59 years were double-blind randomised 4:1 to receive two intramuscular doses of ChulaCov19 50 µg or placebo. Primary endpoints were safety and microneutralization antibody against-wild-type (Micro-VNT50) at day 50. One hundred fifty adults with median (IQR) age 37 (30-46) years were randomised. ChulaCov19 was well tolerated, and most adverse events were mild to moderate and temporary. Geometric mean titres (GMT) of neutralizing titre against wild-type for ChulaCov19 on day 50 were 1367 IU/mL. T-cell IFN-γ-ELISpot showed the highest responses at one week (Day29) after dose 2 then gradually declined. ChulaCov19 50 µg is well tolerated and elicited high neutralizing antibodies and strong T-cell responses in healthy adults.Trial registration number: ClinicalTrials.gov Identifier NCT04566276, 28/09/2020.

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Conflict of interest statement

In accordance with the University of Pennsylvania policies and procedures and our ethical obligations as researchers, we report that D.W. and M.G.A are named on patents that describe the use of nucleoside-modified mRNA as a platform to deliver therapeutic proteins and vaccines. L.H and M.S. are employees of Genevant Sciences Corporation. W.W. is an employee of BioNet-Asia, Co. Ltd. We have disclosed those interests fully to the University of Pennsylvania, and we have in place an approved plan for managing any potential conflicts arising from licensing of our patents. The other authors declare no competing interests.

Figures

Figure 1
Figure 1
CONSORT 2010 study flow diagram.
Figure 2
Figure 2
Solicited local and systemic reactions of ChulaCoV19 vaccine compared with placebo. (A) after first dose (Dose 1), (B) after second dose (Dose 2).
Figure 3
Figure 3
(A) Neutralizing antibody results measured by live virus microneutralization assay (Micro-VNT50) against SARS-CoV-2 wild type virus. Seroconversion defines as Micro-VNT50 titer ≥ 10. (B) SARS-Cov-2-specific serum neutralizing antibody titres measured by pseudovirus neutralization test (psVNT50). Seroconversion defines as psVNT-50 titer ≥ 10. (C) SARS-CoV2 receptor binding domain (RBD) antibody titres measured by ELISA. Seroconversion defines as anti-RBD-IgG ≥ 50 U/mL.
Figure 4
Figure 4
(A) SARS-Cov2 Wild-type Spike-specific T-cell responses measured by IFNγ-ELISpot assays. Seroconversion defines as spike-specific T cell ≥ 50 SCF/106 PBMCs. (B) Kinetics of SARS-CoV2 Specific Antibody and T-cell Immune Responses. Antibodies (anti-RBD, Micro-VNT50 and psVNT50) are expressed as geometric mean titres, and of IFNγ-ELISpot T-cell responses are SPF/million PBMCs. *Indicates a decline in rate from peak; athe T-cell response result at this timepoint was from frozen cells, all other timepoints were assayed using fresh PBMCs).
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References

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