A technician works at the vaccine production workshop of CanSinoBIO in Tianjin on April 25, 2021. (PHOTO / FOR CHINA DAILY)

An inhaled version of CanSino Biologics’ (CanSinoBIO) COVID-19 vaccine triggered immune responses without serious side effects, an early-stage clinical trial showed.

The two-dose candidate requires lower dosages than the injected version and could help CanSinoBIO boost its production capacity, the company’s chief executive said in April.

Two inhaled doses of the Ad5-nCoV vaccine, given 28 days apart, elicited similar level of neutralising antibodies to those of a single injection, according to a peer-reviewed paper.

Two inhaled doses of the Ad5-nCoV vaccine, given 28 days apart, elicited similar level of neutralising antibodies to those of a single injection, according to a peer-reviewed paper

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The readings are based on data from a Phase I trial involving 130 healthy adult participants in China and published on the medical journal the Lancet Infectious Disease on Monday. 

The inhaled vaccine did not cause serious side effects in the study, according to the paper.

Some of the trial participants received the injectible version of the vaccine followed by an inhaling booster 28 days later. The group induced strong neutralizing antibody responses, the report said.

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Authors of the paper includes researchers at Academy of Military Medical Sciences, CanSino Biologics, and other Chinese institutions.

The single-dose injected Ad5-nCoV vaccine is already cleared for use in China, Mexico and Pakistan.