China’s government has approved the world’s first inhaled vaccine against COVID-19, vaccine maker Cansino Biologics announced Sunday. The vaccine, called Convidecia Air, changes the liquid form of the vaccine to an aerosol using a nebulizer. The vaccine can then be inhaled by mouth using a nebulizer device. The needle-free vaccine “can effectively induce comprehensive immune protection in response to SARS-CoV-2 after just one breath,” Cansino said in a statement.
PrePrint (no peer review)
Summary
Background:
Heterologous orally administered adenovirus type 5 vector-based COVID-19 vaccine (Ad5-nCoV) has previously been reported in people who received two doses of CoronaVac (an inactivated vaccine against SARS-CoV-2, by Sinovac ) to be safe and highly immunogenic within 28 days of booster. However, the persistence and safety of antibodies up to 6 months of this regimen has not yet been reported.
Methods:
This is a single-center, open-label, randomized trial on the safety and immunogenicity of heterologous booster immunization with an orally administered aerosolized Ad5-nCoV versus homologous booster immunization with CoronaVac after two priming doses. with CoronaVac in Chinese adults aged 18 years. and older (NCT05043259).
We followed participants in this trial, including 140 in the low-dose aerosol Ad5-nCoV group, 139 in the high-dose aerosol Ad5-nCoV group, and 140 in the CoronaVac group for 6 months.
Neutralizing antibodies (NAbs) against live SARS-CoV-2 wild-type virus and the omicron variant, and receptor-binding domain (RBD)-specific IgG antibodies were detected in serum samples collected at 28 days, 3 months, and 6 months after the booster dose. Serious adverse events ( SAEs) were documented through month 6.
Results:
The low-dose and high-dose heterologous booster immunization groups had GMT of NAb against live wild-type SARS-CoV-2 of 1937.3 [95% CI: 1466.9, 2558.4] and 1350.8 [95% CI 952.6, 1915.3], which were 26.4 times and 18.4 times higher than those in the CoronaVac group (73.5 [95% CI 52.3, 103.3]) at 28 days.
The low-dose and high-dose heterologous booster immunization groups had GMT of NAb against live wild-type SARS-CoV-2 of 530.1 (95% CI: 412.5, 681.1) and 457.6 (95% CI: 349.4, 599.2), which were 26.0 times and 22.4 times more than the CoronaVac group (20.4 [95% CI: 14.3, 29.1]) at 3 months, respectively.
At 6 months , the heterologous low-dose and high-dose booster groups had NAb GMT against live wild-type SARS-CoV-2 of 312.9 (95% CI: 237.7, 411.8) and 251.1 (95% CI: 178.2, 354.0), which were 30.1 times and 24.1 times higher than those in the CoronaVac group (10.4 [95% CI: 7.8; 14.0]), respectively.
Additionally, the low-dose and high-dose heterologous booster groups had NAb GMT against the live omicron variant of 52.0 (95% CI: 37.2, 72.6) and 23.1 (95% CI : 15.7, 33.9) at 28 days, 27.9 (95% CI: 18.8, 41.3) and 23.3 (95% CI 16.2, 33.3) at 3 days months, 16.0 (95% CI 10.9, 23.5) and 12.0 (95% CI 8.5, 16.8) at 6 months, respectively. However, almost all participants had no detectable neutralizing antibodies (NAbs) to the omicron variant in the CoronaVac group at 28 days, 3 months, or 6 months.
No vaccine-related serious adverse events (SAEs) were recorded.
Conclusions :
These data suggested that aerosolized heterologous Ad5-nCoV after priming with two doses of CoronaVac was safely and persistently more immunogenic than three doses of CoronaVac, although immune responses diminished over time.
