CanSino's new crown mRNA vaccine 3+1 sequential safety protection effect is good

Recently, CanSino Biologics released the latest research data of its new coronavirus mRNA vaccine. Data suggest that the vaccine is more protective.

CanSino Biologics novel coronavirus mRNA vaccine CS-2034 (hereinafter referred to as "CS-2034") is a new generation of vaccine with better protection against existing new coronavirus variants, which can induce high-titer neutralizing antibodies against a variety of important variants such as Omicron recognized by the World Health Organization, with stronger broad-spectrum, which can more effectively protect the body from infection by existing variants. Currently, the vaccine is in the clinical phase IIb stage. Recently, the vaccine has made positive progress in clinical studies of safety and immunogenicity.

Studies have shown that sequential boosters with CanSino Biologics novel coronavirus mRNA vaccine in people aged 18 years and older who have received 3 doses of inactivated vaccine are well tolerated, and the level of neutralizing antibodies against the Omicron BA.5 variant is 29 times higher than that of inactivated vaccine. Older people aged 60 years and older are safer to vaccinate and receive stronger immune protection.

The clinical study was divided into two groups, A and B, and the subjects in group A were divided into two age groups: 18-59 years old and 60 years old and above, of which the elderly aged 60 and above accounted for up to 50%. Subjects were randomized to receive 1 dose of CS-2034 (hereinafter referred to as the "mRNA group") or the new crown inactivated vaccine (hereinafter referred to as the "inactivated group") in a ratio of 3:1, in which 0.3ml was vaccinated in the mRNA group and 0.5ml in the inactivated group. Group B was all elderly people aged 60 years and older, and the safety of participants in this group after receiving 1 dose of CS-2034 was observed.

The safety results showed that sequential booster dose of CS-2034 in people who had received 3 doses of inactivated vaccine in the past had a good safety profile, and the incidence and severity of adverse reactions were significantly lower than those reported in the literature of marketed mRNA vaccines. It is worth noting that the safety profile of the elderly group aged 60 years and above is better than that of the adult group aged 18-59 years, which provides strong data support for the elderly population to strengthen the novel coronavirus mRNA vaccine.

Immunogenicity results showed that 28 days after booster, the level of neutralizing antibodies against the prototype strain in the mRNA group was 27 times higher than that of the homologous booster of the inactivated vaccine, and the level of neutralizing antibody against the Omicron BA.1 variant was 23 times that of the homologous booster of the inactivated vaccine.

In addition, cross-neutralizing antibody kinetic studies have shown that 7 days after sequential booster of 1 dose of CanSino Biologics novel coronavirus mRNA vaccine, antibody levels against the currently circulating Omicron BA.5 variant can reach a peak, which is 29 times that of homologous booster of inactivated vaccine. Among them, the subgroup of elderly people aged 60 years and older can also induce higher neutralizing antibodies, and the level of neutralizing antibodies against the Omicron BA.5 variant is 23 times higher than that of homologous booster of inactivated vaccines.

The vaccine is currently in trial production.