Valneva’s COVID-19 vaccine candidate, VLA2001, demonstrated superior virus-neutralizing antibodies compared to the AstraZeneca vaccine.
The study, published in The Lancet Infectious Diseases, compared Valneva’s inactivated, whole-virus COVID-19 vaccine to AstraZeneca’s adenoviral-vectored vaccine. The results showed VLA2001 produced superior neutralizing antibody titer levels, in addition to broad T-cell responses against the spike, membrane, and nucleocapsid proteins.
“This Lancet publication is a strong scientific and developmental validation of the work that has been accomplished at Valneva,” said Juan Carlos Jaramillo, MD, chief medical officer at Valneva. “We are pleased that more detailed results on our inactivated COVID-19 vaccine are now available to the scientific and broader public health communities.”
VLA2001 WAS the first COVID-19 vaccine to receive standard marketing authorization in Europe, and is the only whole virus, inactivated, adjuvanted vaccine to receive marketing authorization in Europe as a primary COVID-19 vaccination in persons 18-50 years old.
The phase 3 trial, COV-COMPARE (NCT04864561), included 4012 adult participants across 26 UK sites. From April 28-June 3, 2021, the trial screened and enrolled participants, 74% of whom were 30 years and older. In the double-blind, randomized, controlled part of the trial, participants aged 30 years and older were assigned 2:1 to receive 2 doses of VLA2001, at 0.5 mL, 33 antigen units (AU). The AstraZeneca cohort received 2 doses of ChAdOx1-S, at 0.5 mL, 2.5 × 108 infectious units per dose).
In the second arm of the trial, participants 18-29 years were administered 2 doses of open-label VLA2001 on study days 1 and 29. The primary outcome was immune response to a 2-dose regimen of VLA2001 after day 43 in adults 30 years and older, as compared to 2 doses of AstraZeneca’s COVID-19 vaccine. The investigators assessed the superiority of geometric mean titers (GMTs) of neutralizing antibodies and noninferiority of seroconversion rate between the 2 vaccines.
VLA2001 was found to produce higher neutralizing GMTs than ChAdOx1-S, at 803.5 vs 576.6. VLA2001 also exhibited noninferior seroconversion rates. Adverse events were reported in 93.6% of participants in the open-label VLA2001 group, 88.8% in the randomized VLA2001 group, and 98.1% of the ChAdOx1-S cohort participants. Most of the reported adverse events were mild-to-moderate in severity.
VLA2001 is produced using Valneva’s Vero-cell platform, which utilizes manufacturing technology from the company’s licensed Japanese encephalitis vaccine, IXIARO. VLA2001 consists of inactivated whole virus particles of SARS-CoV-2 with high S-protein density, combined with two adjuvants, alum, and CpG 1018.