The national Medical Products Administration of China has granted CanSinoBiologics approval for its inhaled vaccine to be used as a booster dose, reports BBC News, and which provides protection after just one breath, according to the company.
Inhaled as a fine mist, Convidecia Air has similar ingredients to its injected vaccine, using a harmless adenovirus as a carrier for the genetic code that teaches the body how to fight COVID.
Other researchers, including teams in the UK and the US, have also been investigating nasal spray vaccines, with scientists saying these might give added immunity in the lining of the nose and upper airways, where COVID typically enters the body.
The inhalant can also top up protection in those who have previously had a jab, trials suggest.
CanSinoBIO received the approval of its clinical trial application for Convidecia Air in March 2021, with studies published in The Lancet indicating that it can induce strong humoral, cellular and mucosal immunity to achieve triple protection and effectively contain the infection and spread of the virus.
Study details
Safety and Immunogenicity of Heterologous Boost Immunisation With an Aerosolized Ad5-nCoV After Two-Dose Priming With an Inactivated SARS-CoV-2 Vaccine CoronaVac in Adults: A Randomised, Open-Label, Parallel-Control Trial
Jing-Xin Li, Shi-Po Wu, Xi-Ling Guo, et al.
Published in The Lancet on 4 January 2022
Abstract
Background
A third dose of homologous or heterologous COVID-19 vaccine is suggested to use in individuals who were previously primed with two doses of inactivated COVID-19 vaccine.
Methods
We conducted a randomised, open-label, parallel-controlled trial to evaluate the safety and immunogenicity of heterologous boost immunisation with an aerosolised adenovirus type-5 vector-based COVID-19 vaccine (Ad5-nCoV) after two-dose priming with an inactivated SARS-CoV-2 vaccine CoronaVac in adults aged ≥18 years. Eligible participants were randomly assigned at a ratio of 1:1:1 to receive a heterologous boost vaccination with low-dose aerosolised Ad5-nCoV, or high-dose aerosolised Ad5-nCoV, or a homologous intramuscular vaccination with CoronaVac. Only laboratory staff were masked to group assignment. The primary endpoint for safety was the incidence of adverse reactions within 14 days after the booster dose. The primary endpoint for immunogenicity was the geometric mean titres (GMTs) of neutralising antibodies against live SARS-CoV-2 virus at 14 days after the booster dose.
Findings
A total of 420 participants were involved, with 140 per group. Participants receiving low-dose or high-dose aerosolised Ad5-nCoV reported significantly lower occurrences of adverse reactions than those receiving CoronaVac did within 14 days after the vaccination (p<0·0001). The low-dose and high-dose aerosolised Ad5-nCoV elicited GMTs of SARS-CoV-2 neutralising antibodies of 744·4(95%CI 520·1, 1065·6) and 714·1(479·4, 1063·7), respectively, at days 14, and 1937·3(1466·9, 2558·4) and 1350·8(952·6, 1915·3), respectively, at days 28, which were significantly higher than those (78·5[60·5, 101·7] at days 14 and 73·5[52·3, 103·3] at days 28) elicited by homologous boosting with CoronaVac, with p values<0·0001. GMTs of neutralising antibody titres against the SARS-CoV-2 B.1.617.2 (delta) variant among the aerosolised Ad5-nCoV recipients were also higher than that observed in the CoronaVac recipients. Th1-skewed cellular immune responses were found in the aerosolised Ad5-nCoV groups. The dose-response relationships of immune responses associated with the dosage of aerosolised Ad5-nCoV as a booster were not identified.
Interpretation
We found that a heterologous boost immunisation with an aerosolised Ad5-nCoV is safe and highly immunogenic in adults who have received two-dose inactivated COVID-19 vaccine CoronaVac as the primary series vaccination.
BBC News article – China approves inhaled Covid vaccine (Open access)
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