On Jun. 14, 2021, Novavax announced data from the first co-administration study of a SARS-CoV-2 vaccine candidate [Novavax, NVX-CoV2373] and an approved influenza vaccine [Seqirus, adjuvanted, trivalent seasonal influenza vaccine (aTIV) or a cell-based, quadrivalent seasonal influenza vaccine (QIVc)].

The findings suggested simultaneous vaccination may be a viable immunization strategy. In addition, the protection afforded by the candidate vaccine was consistent with the main study at 87.5% and 89.8% respectively. A preprint of the manuscript was available at medRxiv.org and had been submitted for peer-review.