With the large-scale epidemic of the new coronavirus, new virus mutants continue to appear, such as Alpha, Beta, Gamma, Delta, Omicron, etc., some of which have stronger Infectious ability or stronger immune escape ability.
As immunity wanes, the researchers analyzed the adverse effects and efficacy of a third dose of the homologous or heterologous booster vaccine in individuals who had previously received two doses of the inactivated vaccine.
On May 20, 2022, researchers from the Beijing Institute of Biotechnology and the Jiangsu Provincial Center for Disease Control were in the Lancet “” The Lancet Respiratory Medicine” published an article entitled “Safety and immunogenicity of heterologous boost immunisation with an orally administered aerosolised Ad5-nCoV after two-dose priming with An inactivated SARS-CoV-2 vaccine in Chinese adults: a randomised, open-label, single-centre trial” research paper.
The study found through a clinical trial of 420 Chinese adults that “mixed fights” greatly improved immunity! After two doses of inactivated vaccine, the use of CanSino inhaled Covid-19 vaccine to strengthen, not only can greatly improve the antibody level, but also has good safety.
COVID-19 vaccine for inhalation, using a nebulizer to nebulize the COVID-19 vaccine into tiny particles to simulate the invasion of COVID-19 from the respiratory mucosa The logic of inhalation enters the respiratory tract and lungs, thereby effectively immunizing the strain.
In this randomized, open-label, controlled trial, researchers analyzed oral nebulized adenovirus type 5 vector vaccine
in Chinese adults who had previously received two doses of the inactivated vaccine. strong>Safety and efficacy of heterologous booster immunization with (Ad5-nCoV). A total of 420 participants aged 18 years and older who had completed two doses of the inactivated vaccine were included and were randomized into 3 groups (1:1:1) to receive a low-dose (0.1ml) or high-dose (0.2ml) mist Ad5-nCoV, and booster immunization with inactivated vaccine.
Adverse reactions were reported by 26 (19%) participants in the low-dose group and 33 (24%) in the high-dose group within 14 days after booster vaccination,
In the homologous inactivated vaccine group, 54 (39%) participants reported adverse reactions. Indicates that the safety of using heterologous boost is higher than that of homologous group.
Within 28 days after booster inoculation, no serious adverse reactions occurred in the heterologous group, and no clinically significant abnormal lung function occurred in the inhalation group of different doses, and the safety was fully verified.
Adverse reactions within 14 days after booster vaccination
The immunogenicity results showed that after using the inactivated vaccine homologous booster, The neutralizing titer was 78.5, compared with 744.4 and 714.1 for the heterologous booster vaccine using low-dose, high-dose oral aerosolized Ad5-nCoV. Indicates that the neutralization titer using heterologous boosting was significantly higher than that of the homologous group.
Twenty-eight days after the booster inoculation, using CanSino inhalation to boost with the new crown vaccine, the neutralizing antibody levels against the original strain in the two dose groups were 18.4-26.4 times that of the homologous booster group, respectively.
In addition, the use of CanSino inhalation booster with the new crown vaccine also has a high level of cross-protection against the Delta mutant strain, and the level of neutralizing antibodies is 18.1-24.0 times that of the inactivated vaccine.
neutralizing antibodies to the original strain before and after booster vaccination
Not only that, but within 28 days after booster vaccination, use CanSino Boosted with Covid-19 vaccine for inhalation, IgA level was significantly higher than that of inactivated vaccine homologous boost.
In conclusion, the results show that the heterologous boosting protocol using aerosolized Ad5-nCoV can produce higher levels of neutralizing antibodies, lower adverse reaction rates, and efficiently induce mucosal immunity, which is a promising candidate for the “mixed” vaccine for Covid-19. The “hit” strengthening strategy provides strong data support.
A multicenter, randomized, double-blind, parallel-controlled efficacy trial of oral nebulized Ad5-nCoV in Mexico is planned for a series of primary immunizations with Ad5-nCoV, the researchers said. carried out later.
Paper link:
https://doi.org/10.1016/S2213-2600(22)00087-X