They tested people to check for evidence of asymptomatic infection and found that people who had two doses of the nasal vaccine showed no signs of infection after three months.
CONCLUSION. A 2-dose intranasal vaccination regimen using NB2155 was safe, was well tolerated, and could dramatically induce broad-spectrum spike-specific sIgA in the nasal passage. Preliminary data suggested that the intranasal vaccination may establish an effective mucosal immune barrier against infection and warranted further clinical studies.
https://insight.jci.org/articles/view/180784
"At least 86.2% participants who completed 2 [nasal vaccine] doses maintained uninfected status, likely without even asymptomatic infection, for at least 3 months.
https://xcancel.com/EricTopol/status/1838937705977110991#m
Seems like we are getting closer to better vaccines being approved.
It sounds much more positive than that. The people who where infected after 2 doses were infected within 3 days of the taking dose while everyone who avoided infection for that 3 day incubation was uninfected for 90 days after that even as protections were dropped and 80% of the population were infected during the same time period. This is ofc only a 31 person sample size and only based on reported symptomatic infections within 90 days so can't get too excited yet.