Why Shares of Vaxart Plummeted 38.6% in May

The tumble was caused by the company's publication of new data about its coronavirus vaccine pill on May 3, which failed to show high levels of neutralizing antibodies in a clinical trial despite showing other signals of immune system activation. Vaxart's coronavirus candidate had shown the same weaknesses in prior data readouts in February, meaning that the latest results served to cement investors' low expectations for its efficacy. Given that competitors like Pfizer and Moderna have both successfully marketed coronavirus vaccines which generate strong antibody responses, it's unlikely that Vaxart's program has much of a future.