The 2021 China Pharmaceutical Conference, hosted by the Chinese Pharmaceutical Association, was recently held in Hangzhou, Zhejiang Province. Junjie Xu, researcher of the Beijing Institute of Biotechnology, Academy of Military Medical Sciences presented the latest developments of Ad5-nCoV and the latest in its innovation and progress that are part of the global fight against the COVID-19 pandemic.
Breakthroughs have been made in the development of the inhaled vaccine which provides a needle-free, non-invasive, and easily administered method to protect against COVID-19. According to clinical trial data published in the medical journal The Lancet in July 2021, one dose of inhaled COVID-19 vaccine, Ad5-nCoV, can induce strong humoral, cellular and mucosal immunity without any severe vaccine-related adverse effects.
Studies have shown that the efficacy of mixing the intramuscular injected and inhaled version of Ad5-nCoV is better than a simple intramuscular injection. Based on clinical research data, neutralizing antibody levels 28 days after being vaccinated with Ad5-nCoV is 4 times that of a single intramuscular injection, and after 6 months, the antibodies remain at the peak level as if administered by a single traditional dose. Additionally, one dose of the inhaled treatment can induce a strong cellular immune response 14 days after administration, equivalent to that produced by the intramuscular injection.
Researchers have found that the use of the inhaled version of Ad5-nCoV for heterologous sequential enhancement is more advantageous than a third, booster dose of the inactivated vaccine, and can cause a significantly high level of IgG antibody and cellular immune response. A person receiving a third booster shot through inhalation results in fewer adverse reactions compared to being vaccinated by an inactivated vaccine, as long as two doses of the inactivated vaccine have been completed. In addition, sequential immunization of the inhaled vaccine can induce highly effective neutralizing antibodies against prototype coronavirus, as well as its Alpha, Beta, Gamma and Delta variants.
Tao Zhu, Chief Scientific Officer of CanSinoBIO said: “CanSinoBIO’s COVID-19 vaccine can be administered through both intramuscular injection and mucosal immunization. Research has shown that respiratory droplets and close contact are still the primary ways humans contract COVID-19. Hence the inhaled treatment can provide additional protection against COVID-19 by stimulating the immune response in the mucosa of the respiratory tract.”
Junjie Xu pointed out that nebulized inhalation does not require "injection", only "inhalation", enabling it to be more accessible and easier to use and also improves the safety of the application as well as convenience. The efficacy of strengthening a person’s immune response is remarkable and particularly suitable for large-scale booster immunization programs of at-risk populations.
Coronavirus invades the body mainly by infecting the epithelial cells of the respiratory mucosa. The respiratory mucosa is the first part of the body to be exposed to a large number of antigens. The inhaled dosage form can not only cause a specific immune response in the local mucosa, but also cause a systemic immune response.