An investigational oral influenza vaccine from Vaxart Inc has shown favorable results in a phase 2 challenge trial comparing it with placebo and an injectable quadrivalent influenza vaccine.

The results of the trial revealed that the tablet reduced the rate of infection with influenza by 48%, while the QIV reduced the infection rate by 38%.

The phase 2 randomized, double-blind study consisted of 3 groups of adult subjects ages 19 through 49. The participants either received a dose of the oral tablet vaccine and a placebo injection, a placebo tablet and QIV injection, or a placebo tablet and placebo injection.

After 90 to 120 days, the participants were exposed intranasally to a strain of influenza A. If a subject had detectable viral shedding on any day after the first 36 hours from exposure, they were deemed to be infected with influenza.