Aerosolized inhalable COVID-19 vaccine developed by CanSinoBIO is on display at the Fifth Hainan International Health Industry Expo on November 12, 2021. Photo: VCG

The aerosolized AD5-Ncov third-generation vaccine developed by CanSinoBIO proved to be a better choice for mixed vaccination booster, the latest research data revealed.

The inhaled booster vaccine elicited a potent immune response against the Omicron variant after inactivated COVID-19 vaccine priming, according to data published by CanSinoBIO in medRvix, the preprint server for Health Sciences operated by Cold Spring Harbor Laboratory, on March 10.

The results found that the Ad5-nCoV booster induced a potent neutralizing activity against the wild-type virus and the Omicron variant, while the aerosolized Ad5-nCoV generated the greatest neutralizing antibody responses, several times higher than traditional inactivated shots, against the Omicron variant at day 28 after booster vaccination.

The findings suggest that inactivated vaccine recipients could consider adenovirus-vectored vaccine boosters in China and that aerosolized Ad5-nCoV may provide a more efficient alternative in response to the spread of the Omicron variant, said the paper.

The inhaled vaccine simulates the process of natural infection and it can induce human respiratory mucosal immunity with a higher level of protection. 

As COVID-19 cases sprouted in several Chinese cities like Shanghai and Shenzhen, voices calling for quicker R&D and wider approval of new generation vaccines against variants are louder amid health experts.

Omicron-specific shots, domestic mRNA vaccines and nasal spray vaccines are also being developed in China. 

Experts defined the third-generation vaccine as using a relatively harmless, unrelated virus called adenovirus, which has been engineered to carry DNA encoding the desired viral protein target such as the SARS-CoV-2 spike protein.

Zhu Tao, chief scientist of CanSinoBIO has called on the government to approve and adopt new-generation COVID-19 vaccines with improved quality and safety as early as possible to enhance national immunization levels.

"China should accelerate efforts to strengthen overall immunity levels in 2022 with more diverse types of vaccines for booster shots that can reactivate the level of antibodies against the virus and its variants," Zhu told the Global Times.