CanSinoBIO vaccine production line in Tianjin Photo: Hu Yuwei/GT

The world's first aerosolized adenovirus type-5 vector-based COVID-19 vaccine (Ad5-nCoV) was proven to be safe and effective as a booster shot after two doses of inactivated shots, according to a recent report published on the Lancet. 

A heterologous booster vaccine with an orally administered aerosolized Ad5-nCoV is safe and highly immunogenic in adults who had previously received two doses of CoronaVac as the primary series vaccination. It could elicit a high neutralizing capability against both the wild-type and Delta SARS-CoV-2 variants, which is significantly higher than that of WHO international standard, said the paper.

The inhaled vaccine is now under Phase III trials, and will try to apply it to diverse markets across the world with approval, the Global Times learnt from the company.

The research results published on the Lancet on May 20 showed that the heterologous booster regimen with the aerosolized Ad5-nCoV was safe and significantly more immunogenic than a homologous boost with Chinese-developed inactivated jabs, showing lower occurrence of adverse reactions.

Participants who received aerosolized Ad5-nCoV also had a cross-neutralizing capability to the SARS-CoV-2 Delta variant by as much as an 18 to 24 times more compared with those who received a homologous boost with the inactivated shot 28 days after a booster vaccination.

Between September 14 and 16, 2021, a total of 420 participants were enrolled into the trials, with 140 (33 percent) participants per group. Adverse reactions were reported by 26 (19 percent) participants in the low dose group and 33 (24 percent) in the high dose group within 14 days after the booster vaccination.

The inhaled vaccine, jointly developed by CanSino Biologics (CanSinoBIO) and researchers from the Institute of Military Medicine under the Academy of Military Sciences led by Chen Wei, has obtained the national drug regulator's approval to start clinical trials in March 2021.

Videos of the inhaled vaccine have previously gone viral on Chinese social media when the product was unveiled at the Fifth Hainan International Health Industry Expo in December 2021, with some visitors likening the experience to "drinking a bottle of milk tea."

The Global Times learned that it is no different in terms of virus species, cell banks, production technology, or the preparation formula from the company's single-dose Ad5-nCoV COVID-19 vaccine, which is already in use and was just approved by the WHO - it just has an additional atomization inhalation device.

The inhaled vaccine can stimulate an immune response in the mucous membranes of a person's respiratory tract. This version is less painful and more accessible, to vulnerable groups such as children, experts said.

The vaccine can be atomized into tiny particles in a device and then inhaled into the respiratory tract and lungs to stimulate mucosal immunity, a Beijing-based immunological expert who prefers not to be identified told the Global Times.

Research has confirmed that respiratory droplets and close contact are still the main transmission routes of the novel coronavirus disease.