Tianjin, January 11, 2022 – CanSino Biologics Inc. (“CanSinoBIO”) (SSE: 688185, HKEX: 06185) today announced that Preprints with The Lancet, a collaboration between the research sharing platform SSRN and The Lancet, published a clinical study on the safety and immunogenicity of CanSinoBIO’s Recombinant COVID-19 Vaccine（Adenovirus Type 5 Vector）for Inhalation Convidecia™as a heterologous booster1. The results of the study indicated that a heterologous booster with one dose of the Inhalation Convidecia™ for adults aged 18 years and above, who have received two doses of inactivated COVID-19 vaccine, can induce a higher level of neutralizing antibodies than those with a homogeneous booster of inactivated vaccine.
CanSinoBIO’s inhaled COVID-19 vaccine provides unique advantages and represents an innovative solution in response to the COVID-19 pandemic. The needle free, non-invasive treatment aims to provide quick, regular and mass-scale protection with easy administration. The inhaled vaccine trains the immune memory function of the body by imitating the natural infection of the virus, which not only stimulates humoral and cellular immunity, but also efficiently induces mucosal immunity to achieve triple, comprehensive protection.
The study showed that boosting the inactivated vaccine with the Inhalation Convidecia™stimulates a strong mucosal immune response. The level of RBD-specific IgA-binding antibody was detected in the serum of the subjects 14 days after vaccination.
Overview of Clinical Study
The study was randomized, non-blind and parallel-controlled, with 420 participants being randomly assigned to three 140-person groups. One group received one low dose (0.1 ml) of the Inhalation Convidecia™one group received one high dose (0.2 ml) of the inhaled vaccine; and the last group received an inactivated vaccine administered by intramuscular injection. The study showed the safety and immunogenicity of the Inhalation Convidecia™ as a booster using only one fifth or two fifths dosage of its intramuscular version.
Proven Safety and Efficacy of CanSinoBIO’s Inhaled Vaccine
The data on safety results showed that there were fewer cases of adverse events after the heterologous booster of the Inhalation Convidecia™than those administered with a homologous booster of inactivated vaccine. No serious adverse events were observed in the two inhalation groups 28 days after the booster was administered, nor were there any reports of clinically significant lung function abnormalities.
The data on immunogenicity showed that the inhaled heterologous booster elicited a significantly higher level of neutralizing antibodies than those with a homogeneous booster of inactivated vaccine. There was no significant difference in immune response between the two inhalation groups, which were 6.7 to 10.7 times higher than that observed in the third group with a homologous booster between days 14 and 28 after the booster shot. In addition, the level of neutralizing antibodies peaked on day 28 after the inhaled booster at 6054.1 (95% CI 4584.1, 7995.0) for the low-dose group and 4221.3 (2976.9, 5985.3) IU/ml for the high-dose group. It also showed that the Inhalation Convidecia™provided a high level of cross-protection against the Delta variant, with higher levels of neutralizing antibodies elicited than that by inactivated vaccines.
Neutralizing antibodies against wild-type SARS-CoV-2 before and after a boost vaccination
Compared with the inactivated booster, significantly increased 2019-nCoV spike protein-specific IFN-γ and IL-2 ELISA can be detected 7 days after the inhalation booster. The expression levels of INF-γ and IL-2 in the inhalation booster group were 6 to 10 times and 4 to 5 times higher than those in the inactivated vaccine booster group, respectively. It indicates that compared to the inactivated vaccine homologous booster, the inhaled heterologous booster can significantly induce Th1-type cellular immune response, while factors such as gender and age have no effect on cellular immune response.
SARS-CoV-2 spike-specific cytokine T cells responses before and after receiving a boost vaccination
In addition, the RBD-specific ELISA antibody level induced by the inhaled heterologous booster was significantly higher than that of the inactivated vaccine homologous booster 28 days after administration, the RBD antibody level in the low-dose inhalation group was approximately 13 times than that of the inactivated vaccine homologous group.
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