Scientific Reports (Jan 2024)

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

  • Thanyawee Puthanakit,
  • Eakachai Prompetchara,
  • Sivaporn Gatechompol,
  • Chutitorn Ketloy,
  • Arunee Thitithanyanont,
  • Anan Jongkaewwattana,
  • Supranee Buranapraditkun,
  • Sasiwimol Ubolyam,
  • Stephen J. Kerr,
  • Jiratchaya Sophonphan,
  • Tanakorn Apornpong,
  • Wonngarm Kittanamongkolchai,
  • Sarawut Siwamogsatham,
  • Somchai Sriplienchan,
  • Kanitha Patarakul,
  • Tuangtip Theerawit,
  • Pathariya Promsena,
  • Rapisa Nantanee,
  • Siwaporn Manomaisantiphap,
  • Sarun Chokyakorn,
  • Lina Hong,
  • Mijo Samija,
  • David C. Montefiori,
  • Hongmei Gao,
  • Amanda Eaton,
  • Wassana Wijagkanalan,
  • Mohamad-Gabriel Alameh,
  • Drew Weissman,
  • Kiat Ruxrungtham,
  • ChulaVac001-Phase 2 study team

DOI
https://doi.org/10.1038/s41598-023-49653-6
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 10

Abstract

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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.