Timing and sequence of vaccination against COVID-19 and influenza (TACTIC): a single-blind, placebo-controlled randomized clinical trial

• DOI: 10.1016/j.lanepe.2023.100628
• Publication Date: 2023-04-12T13:07:16Z
• Authors: Elisabeth A. Dulfer; Büsra Geckin; Esther J.M. Taks; Corine H. Geurtsv...; Helga Dijkstra; Liesbeth van Emst; Christa E. van de...; Djenolan van Mourik; Petra C. Koopmans; Jorge Domínguez-A...; Reinout van Crevel; Josephine S. van ...; Marien I. de Jonge; Mihai G. Netea
• Keywords: Booster (rocketry); Booster dose

Novel mRNA-based vaccines have been used to protect against SARS-CoV-2, especially in vulnerable populations who also receive an annual influenza vaccination. The TACTIC study investigated potential immune interference between the mRNA COVID-19 booster vaccine and quadrivalent vaccine, determined if concurrent administration would effects on safety or immunogenicity.TACTIC was a single-blind, placebo-controlled randomized clinical trial conducted at Radboud University Medical Centre, Netherlands. Individuals ≥60 years, fully vaccinated were eligible for participation into one of four groups: 1) 0.5 ml vaccination Vaxigrip Tetra followed by 0.3 BNT162b2 21 days later, (2) vaccination, (3) with (4) only (reference group). Primary outcome geometric mean concentration (GMC) IgG spike (S)-protein SARS-CoV-2 virus, after We performed non-inferiority analysis compared alone predefined margin -0.3 log10-scale.154 individuals participated from October, 4, 2021, until November, 5, 2021. Anti-S GMCs co-administration reference group 1684 BAU/ml 2435 BAU/ml, respectively. Concurrent did not meet criteria (estimate -0.1791, 95% CI -0.3680 -0.009831) antibodies showed significantly lower neutralization capacity group. Reported side-effects mild differ groups.Concurrent both is safe, but quantitative functional antibody responses marginally alone. Lower protection cannot be excluded, although additional larger studies required confirm this.EudraCT: 2021-002186-17.The supported ZonMw Programme.