Publication date: Dec 10, 2025
A U. S. multisite trial was conducted and explored whether blunting of mRNA COVID-19 vaccine immunogenicity occurred when administered simultaneously with influenza vaccine. Persons ≥5 years of age received either quadrivalent inactivated influenza vaccine (IIV4) or saline placebo simultaneously with an initial or booster dose of mRNA COVID-19 vaccine. Those receiving placebo with mRNA COVID-19 vaccine received IIV4 7-14 days later. SARS-CoV-2 antibody was assessed by pseudovirus neutralization (D614G, BA. 4/BA. 5, and XBB. 1.5) at baseline and 28 days following mRNA COVID-19 vaccine primary series or booster dose. Of 335 randomized participants, 157 were in the simultaneous group and 150 the sequential group. Post-vaccination geometric mean SARS-CoV-2 ID50 titers for the ancestral D614G strain and BA. 4/5 variant (simultaneous versus sequential) were 4357. 1 versus 4492. 3(p = 0. 79) and 1547. 8 versus 1463. 8(p = 0. 69), respectively. Blunting of mRNA COVID-19 vaccine immunogenicity was not observed when mRNA COVID-19 and influenza vaccines were administered simultaneously. TRIAL REGISTRATIONClinicalTrials. gov ID: NCT05028361.
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| Concepts | Keywords |
|---|---|
| 5years | Immunogenicity |
| Covid | mRNA-COVID-19 vaccine |
| Inactivated | |
| Nct05028361 | |
| Vaccine |
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | strain |
| disease | MESH | COVID-19 |