Ipsilateral and contralateral coadministration of influenza and COVID-19 vaccines produce similar antibody responses
David Pattinson, Peter Jester, Chunyang Gu, Lizheng Guan, Tammy Armbrust, Joshua G. Petrie, Jennifer P. King, Huong Q. Nguyen, Edward A. Belongia, Peter Halfmann, Gabriele Neumann, Yoshihiro Kawaoka
Abstract
BACKGROUND: World Health Organisation (WHO) and USA Centers for Disease Control and Prevention (U.S. CDC) recommendations now allow simultaneous administration of COVID-19 and other vaccines. We compared antibody responses after coadministration of influenza and bivalent COVID-19 vaccines in the same (ipsilateral) arm vs. different (contralateral) arms. METHODS: Pre- and post-vaccination serum samples from individuals in the Prospective Assessment of COVID-19 in a Community (PACC) cohort were used to conduct haemaglutination inhibition (HI) assays with the viruses in the 2022-2023 seasonal influenza vaccine and focus reduction neutralisation tests (FRNT) using a BA.5 SARS-CoV-2 virus. The effect of ipsilateral vs. contralateral vaccination on immune responses was inferred in a model that accounted for higher variance in vaccine responses at lower pre-vaccination titers. FINDINGS: Ipsilateral vaccination did not cause higher influenza vaccine responses compared to contralateral vaccination. The response to SARS-CoV-2 was slightly increased in the ipsilateral group, but equivalence was not excluded. INTERPRETATION: Coadministration of influenza and bivalent COVID-19 vaccines in the same arm or different arms did not strongly influence the antibody response to either vaccine. FUNDING: This work was supported by the U.S. CDC (grant number: 75D30120C09259).