Preliminary results from Vaxart's clinical trial showed VXA-CoV2-1 to be generally well-tolerated, with no severe adverse events reported among the study's 495 participants. Notably, VXA-CoV2-1 also triggered a T-cell response that Vaxart says could help combat the novel coronavirus.
"Our Phase I results highlight the importance of our differentiated vaccine design, as they suggest VXA-CoV2-1 could have broad activity against existing and future coronavirus strains," Vaxart CEO Andrei Floroiu said in a press release. "These results are timely, as we are seeing the emergence of new variants less responsive to first-generation vaccines."
However, VXA-CoV2-1 did not appear to produce neutralizing antibodies in participants who received one dose of the vaccine candidate. Researchers say a lack of neutralizing antibodies could reduce the vaccine's ability to defend against COVID-19.
Vaxart's stock soared more than 150% in the days leading up to the release of its trial results. Investors appear to have been overly optimistic about VXA-CoV2-1's potential to become a key weapon in the war against COVID-19, due to its potential logistical advantages. As a room-temperature stable oral vaccine, VXA-CoV2-1 would be easier to distribute, store, and administer than injectable vaccines with special cold storage requirements.
But due to its apparent failure to produce neutralizing antibodies in patients, Vaxart's vaccine candidate likely has little chance of gaining the type of broadscale distribution obtained by industry leaders Pfizer and Moderna.