Novel Intranasal Influenza Vaccine Shows Tolerability, Safety, and High Immune Response

This article is part of Infectious Disease Advisor‘s coverage of IDWeek 2018, taking place in San Francisco, CA. Our on-site staff will be reporting on the latest breaking research and clinical advances in infectious diseases. Check back regularly for highlights from IDWeek 2018.

SAN FRANCISCO — NasoVAX, a replication-deficient adenovirus-based nasal spray flu vaccine, has demonstrated tolerability and safety as well as higher cellular immune response compared with a common injectable vaccine. This research was presented at IDWeek 2018, held October 3-7, 2018, in San Francisco, California.

This study included 60 healthy adult participants who were randomly assigned to receive either an A/California 2009-based monovalent NasoVAX in 10⁹, 10¹⁰, or 10¹¹ doses of viral particles or a saline-based placebo. NasoVAX demonstrated tolerability without serious adverse events or fever. Placebo and all doses of treatment experienced similar rates of solicited symptoms, including headache, sore throat, and nasal congestion. Immune measures of hemagglutination inhibitor titers of >1:40 were set as delineation for development of seroprotection. At day 29, the seroprotection rate of NasoVAX 10⁹ was 80% (95% CI, 51.9%-95.7%), doses of 10¹⁰ viral particles were 100% (95% CI, 78.2%-100%) protective, and doses of 10¹¹ viral particles were also 100% (95% CI, 78.2%-100%) protective.

The study researchers were blinded to the assignment of participants to placebo group vs NasoVax group, and followed participants for local or systemic side effects to monitor for safety. Neutralizing antibody and hemagglutination inhibition were among immune measures taken at 0, 0.5, 1, 3, and 6 months. Additionally, 20 other participants, assessed in tandem, were given Fluzone® injectable influenza vaccine that also contained an A/California 2009 ingredient. Of note, at day 29, seroprotection of the Fluzone group was measured at 95% (95% CI, 75.1%-99.9%). At days 1 and 8, ɣ-interferon ELISpot was also measured, demonstrating the highest values to participants who received NasoVAX 10¹¹, and lowest protection in the participants who received Fluzone. Both treatment and placebo were administered as a 0.25-mL nasal spray for both nostrils.

The study researchers conclude that the “NasoVAX intranasal influenza vaccine was well tolerated and elicited comparable antibody responses and nearly 6-fold higher cellular immune responses than a licensed injectable vaccine.”

All authors are employees, shareholders, and/or research contractors for Altimmune, Inc.

Visit Infectious Disease Advisor‘s conference section for continuous coverage live from IDWeek 2018.

Reference

Tasker S, Krishnan V, Bart S, et al. Safety and immunogenicity of NasoVAX, a novel intranasal influenza vaccine. Poster presented at: IDWeek; October 3-7, 2018; San Francisco, California. Abstract 2554.