A technician works during the fill and finish process for the CanSino vaccine at the Solution Biologics factory in Kuala Lumpur, Malaysia, Sept 8, 2021, during a test run. XINHUA BEIJING - Clinical trial in China shows that an inhalable COVID 19 booster vaccine is safe and effective in adults.
Adenoviruses type 5 vector-based COVID 19 vaccine Ad 5 nCoV administered via oral inhalation have been developed by scientists led by Chen Wei with the Academy of Military Medical Sciences in China.
Chen and the researchers from the Jiangsu Provincial Center for Disease Control and Prevention conducted a randomized, open-label, controlled trial to evaluate the vaccine's safety and immunogenicity as a booster jab in 420 Chinese adults who had previously received two doses of inactivated vaccine.
Eligible participants were randomly assigned between Sept 14 and 16 last year to receive either a low dose or a high dose inhalable vaccine, or the vaccine identical to their previous two intramuscular shots, as a control group, according to a study published recently in the Lancet Respiratory Medicine.
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The results showed that the low dose group had a concentration of serum neutralizing antibodies of 744.4 and the high dose group days after the booster dose, which was significantly higher than that in the control group of 78.5.
The vaccine-induced neutralizing antibodies can bind to the coronavirus and prevent it from infecting cells.
Only 26 and 33 participants reported adverse reactions in the low dose group and the high dose group, respectively, within 14 days of the booster vaccine, significantly fewer than the 54 reported in the control group, according to the study.
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The researchers concluded that a heterologous booster immunization with an aerosolized Ad 5 nCoV in previously vaccineed adults is safe and highly immunogenic.
They are planning to do a multicenter, double-blind, parallel-controlled efficacy trial of the inhaled vaccine as a booster dose after a primary series of immunization with Ad 5 nCoV in Mexico.