San Francisco-based Vaxart (NASDAQ: VXRT) said its experimental coronavirus vaccine taken by mouth showed promising results in an early-stage clinical trial of 35 healthy adults.
Vaxart scientists divided volunteers between ages 18 and 54 into three groups. The first received two low doses of the vaccine – called VXA-CoV2-1 – 29 days apart, while the remaining groups received a single low or high dose.
The vaccine, which is in a small tablet, generated a type of T-cell responsible for destroying virus-infected cells in about 75% of volunteers who received a single low or high dose, the company said. It said the reported responses were higher than those seen in Moderna’s (NASDAQ:MRNA) and Pfizer’s (NYSE:PFE) vaccines.
However, neutralizing antibodies were not detected in volunteers after a single dose, Vaxart said. Researchers believe the antibodies play an important role in defending cells against the virus. The company said it is now assessing antibody responses from second doses after antibodies were detected in nasal swab samples of two-dose volunteers.
The data will be presented Wednesday afternoon at the New York Academy of Sciences Symposium.
"The most exciting thing about the [phase one data] is we can get a very, very, strong T-cell response even after one dose," Vaxart chief scientific officer Sean Tucker said, adding that T-cells are probably "underappreciated" compared to antibodies in fighting the virus.
VXRT shares took a tumble, $13.53, or 58%, to $9.80.
