Vaxart Inc (VXRT)

[AgeOfReason]

See the Motley Fool article of April 30th: https://www.fool.com/investing/2021/04/30/why-vaxart-stock-is-soaring-today/ . Besides mentioning the info in the press release it says "Additionally, Vaxart has become increasingly popular among traders on Reddit and other social media platforms in recent weeks. This is no doubt amplifying the moves in its stock price, which is likely to remain volatile."

See also https://scrip.pharmaintelligence.informa.com/SC144270/Your-Annual-COVID-19-Vaccine-Booster-Could-Be-A-Pill-Or-A-Spray which says in part the following:

'In addition to convenience, oral and nasal vaccine candidates have other potential advantages in that they elicit immune response in a different way to subcutaneous or intramuscular vaccines.

In subcutaneous or intramuscular vaccines, the primary immune response is systemic humoral immunity, in which B-cells generate antibodies (IgG) against the pathogen in the blood. They tend to produce limited cellular immunity from T-cells, and only weak protection at the mucosal surfaces, which include the nasal cavity and the stomach.

The reverse is true with oral and nasal vaccines – delivering a vaccine via mucosal surfaces generates mucosal antibodies (IgA) as well as a T-cell response, while systemic antibody response (IgG) can be limited.

A vaccine that could provide a mucosal immune response in the nose and mouth is likely to be preferable against an airborne respiratory virus like SARS-CoV2, as it would provide a barrier at the infection site.

Vaxart and Altimmune have both made progress in the last 12 months for their respective oral and nasal drug delivery platforms, and they see applications for their products across a range of infectious diseases.

A Phase II head-to-head challenge study of Vaxart’s oral flu vaccine candidate versus Sanofi’s Fluzone shot and a placebo showed superior efficacy to Sanofi’s established product. Illness rates were 39% lower in those given Vaxart’s oral vaccine compared with unvaccinated subjects, and 27% lower than in those vaccinated with Fluzone.

The trial was funded by the US Biomedical Advanced Research and Development Authority (BARDA) and was published in the Lancet Infectious Diseases in January 2020.

The results also showed that Vaxart’s vaccine generated less than one tenth of the serum neutralizing antibodies of the injectable product, yet it protected as well. This illustrated the importance of the T cell immunity, as well as the small but significant levels of mucosal antibodies generated.

Explaining the mechanism on a HC Wainwright & Co investor call in March, Vaxart’s founder and chief scientific officer Sean Tucker said: “A little bit of mucosal B-cells goes a long way”.

...
Vaxart believes its approach of targeting two of the virus’ proteins could be another key differentiator for its vaccine as the N protein is more conserved than the S protein, and therefore could hold out against new SARS-CoV2 variants.

This theory has yet to be clinically tested, but the candidate has passed the first hurdle, with preliminary Phase I trial data meeting its primary and secondary endpoints, with no reports of severe adverse indications.

As in the flu trial, the vaccine generated CD8+ cytotoxic T-cell responses in a majority of patients that may provide long lasting memory, proinflammatory Th1 cytokines and IgA responses, and elevated mucosal homing receptors for B-cell immune response.

The company is now gearing up for Phase IIa immunogenicity and dose-ranging study in Q2, which once complete, will immediately be followed by a Phase IIb efficacy study.

Vaxart’s founder and chief scientific officer Sean Tucker said the world could be stuck on a ‘hamster wheel’ trying to constantly update injected vaccines that target a mutating S protein.

He believes its approach of targeting the N and S proteins with an oral vaccine could tackle emerging variants of concern.

“The best way to do that is essentially hand out tablets because then you don't have to line up and wait for the syringes to go into people's arms.”

Highlighting the benefits of targeting the N protein he said: “The South African strain that everybody's concerned about has only one amino acid difference in the N protein compared to the original Wuhan, so it's again a very well conserved target…for T-cells.” '