Seasonal trivalent inactivated influenza vaccine with topical imiquimod in immunocompromised patients: A randomized controlled trial. Issue 3 (September 2021)

• Record Type: Journal Article
• Authors: Mombelli, Matteo; Hoschler, Katja; Cavassini, Matthias; Pascual, Manuel; Manuel, Oriol
• Is Part Of: Journal of infection. Volume 83:Issue 3(2021)
• Page Start: 354
• Page End: 360
• Publication Date: 2021-09
• Subjects: Influenza -- Influenza vaccines -- Imiquimod; Infection -- Periodicals; Bacterial Infections -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.905
• DOI: 10.1016/j.jinf.2021.07.010
• Languages: English
• ISSNs: 0163-4453

Abstract

Highlights: Effect of topical imiquimod before influenza vaccine in immunocompromised patients is unknown. We enrolled 35 kidney transplant recipients and 35 people living with HIV in a RCT. Topical imiquimod was safe but did not improve influenza vaccine immunogenicity. Vaccine response was better in people living with HIV compared to kidney transplant recipients. Abstract: Background: The effect of the Toll-like receptor 7 agonist imiquimod before intradermal (ID) or intramuscular (IM) influenza vaccine in immunocompromised hosts is unknown. Methods: In this open-label randomized controlled trial, kidney transplant recipients (KT) and people living with HIV (PLWH) were randomized to receive IM trivalent inactivated influenza vaccine alone (IM), IM vaccine after topical imiquimod (imi+IM) or ID vaccine after topical imiquimod (imi+ID). Immunogenicity was assessed by hemagglutination inhibition assay. The primary outcome was vaccine response, defined as seroconversion to at least one viral strain at day 21. Results: Seventy patients (35 KT and 35 PLWH) received IM (24), imi+IM (22), or imi+ID (24) vaccine. Vaccine response was 61% (14/23) with IM, 59% (13/22) with imi+IM, and 65% (15/23) with imi+ID vaccine ( P = 0.909). Vaccine response was associated with HIV infection compared to kidney transplantation (adjusted-OR 3.74, 95% CI 1.25 – 11.23, P = 0.019), but not with imiquimod application nor ID injection. After vaccination, seroprotection to all viral strains was 79% (19/24) with IM, 68% (15/22) with imi+IM, and 70% (16/23) with imi+ID ( P = 0.657). We did not observe any vaccine-related severe adverse event. Conclusions: In our study, topical imiquimod did not improve the immunogenicity of influenza vaccine in KT and in PLWH.