Vaxart stock crashed Wednesday after its oral Covid-19 vaccine failed to produce detectable neutralizing antibodies in "most subjects." Researchers tested the experimental Vaxart (VXRT) drug in 35 healthy adults. One group received two doses of the oral drug 29 days apart. The other group received single low or high doses of the coronavirus vaccine.
Although the vaccine triggered several immune responses, neutralizing antibodies weren't among them. These antibodies bind to a virus in a way that prevents it from replicating. In response to the Phase 1 study, Vaxart stock plummeted.
On today's stock market, Vaxart stock plunged 57.8% to 9.85.
Vaxart Stock Plunges
In the Phase 1 study, Vaxart said its coronavirus vaccine prompted T cell responses to the spike protein on the outside of the SARS-CoV-2 virus. Other increases indicated B cells were also activated. B cells are another type of white blood cell.
The Vaxart drug also prompted the response of cytokines responsible for orchestrating the body's immune response to a viral infection.
But researchers didn't detect neutralizing antibodies in the serum of "most subjects." They also couldn't find evidence of the immunoglobulin antibody. That hampered Vaxart stock on Wednesday, sending it down in massive volume.
An Oral Covid-19 Vaccine
An oral coronavirus vaccine would be a huge step forward. It would help ease anxiety for people nervous about needles. It would also be easier to administer in a socially distant way that also puts less burden on the health care system.
Further, Vaxart's tablet is stable at room temperature. In comparison, Pfizer (PFE) and BioNTech's (BNTX) coronavirus vaccine must be transported and stored at ultracold temperatures. Moderna's (MRNA) is stable in a standard refrigerator for 30 days.
Vaxart stock could rebound if Chief Executive Andrei Floroiu's claim that the vaccine might be "more broadly protective" holds up in additional testing.
Most coronavirus vaccines — both authorized and in testing — go after the spike protein on the outside of the virus. But the spike protein is mutating, evidenced by strains in the U.K. and South Africa. By targeting both the spike protein and what's known as the nucleoprotein, Vaxart says its vaccine might protect against mutated forms of the virus.
"We expect that our vaccine will be less impacted by new variants than injectable vaccines," Vaxart Chief Scientific Officer Sean Tucker said in a written statement.
Follow Allison Gatlin on Twitter at @IBD_AGatlin.