Phase 1 Clinical Trial Assesses Nasal Influenza Vaccine in Pediatric Populations

The National Institutes of Health (NIH) is working alongside different vaccine development companies to bring innovative influenza vaccine candidates to clinical trials.

In the latest early-stage clinical trial, the NIH is evaluating the safety and efficacy of an experimental nasal influenza vaccine for children between the ages of 9 and 17 years. An important objective of the study is to determine if the combination of the licensed and candidate vaccine has the ability to create broader protection against influenza viruses compared with the licensed vaccine alone.

The trial is underway at Saint Louis University, Missouri, a part of the Vaccine and Treatment Evaluation Units, a network of research sites evaluating experimental vaccines against infectious diseases that is funded and managed by the NIH’s National Institute of Allergy and Infectious Diseases (NIAID).

The vaccine candidate is produced by FluGen and is a monovalent live attenuated influenza H3N2 M2SR vaccine. The vaccine contains viruses that have been modified to delete a portion of the M2 gene. From this point, the viruses activate the body’s immune defenses without the production of infectious viruses.

The trial, which launched in August, is led by Daniel Hoft, MD, PhD, director of the Division of Infectious Diseases, Allergy and Immunology at Saint Louis University School of Medicine.

The primary objective of the phase 1 trial is to assess the safety and reactogenicity of a monovalent live attenuated influenza H3N2 M2SR vaccine, according to information provided on Clinicaltrials.gov. Secondary objectives are to identify circulating and mucosal antibody responses induced by the H3N2 M2SR vaccination and to identify cellular immune responses induced by H3N2 M2SR vaccination.

The trial will enroll 50 participants in a double blind, randomized, placebo-controlled setting. Half of the participants will receive 1 dose of M2SR intranasally on day 1, followed by 1 dose of intramuscular injection of a licensed, quadrivalent seasonal influenza vaccine (QIV) on day 92. The remaining half will receive 1 dose of a saline placebo intranasally on day 1 followed by 1 intramuscular injection of the QIV on day 92.

According to the NIH statement, investigators will perform an array of tests on blood samples at 4 time points following the first vaccination as well as 3 weeks after the second vaccination. Dr. Hoft and his team will look for evidence of immune responses from antibody-producing cells as well as from the cellular arm of the immune system.

The vaccine has been tested previously in animal trials which found that the single replication virus prompted a robust immune response similar to a natural influenza infection. A phase 1 trial was also conducted in healthy adults and the vaccine was found to be safe and capable of generating robust immune responses.

Investigators are hopeful that the participants who receive the candidate vaccine will have a robust immune response to not only H3N2 but also against strains of influenza that are not direct matches to the vaccine strain.

The trial is scheduled to run for 13 months and has an estimated primary completion date of July 31, 2019.

A phase 3 trial—that is not sponsored by NIAID—evaluating the vaccine candidate in healthy adults is also currently underway.