China launches a Covid-19 vaccine that can be inhaled through the mouth

The Chinese city of Shanghai started administering an inhalable Covid-19 vaccine on Wednesday in what appears to be a world first.

The vaccine — a mist that is sucked in through the mouth — is being offered for free as a booster dose for previously-vaccinated individuals, according to an announcement posted on an official city social media account.

Needle-free vaccines may persuade people who don't like getting a shot to get vaccinated, and also help expand vaccination in poor countries, because they are easier to administer.

A video posted by an online Chinese state media outlet showed people at a community health centre sticking the short nozzle of a translucent white cup into their mouths. Accompanying text said that after slowly inhaling, one individual held his breath for five seconds, with the entire procedure completed in 20 seconds.

“It was like drinking a cup of milk tea," one Shanghai resident said in the video.

"When I breathed it in, it tasted a bit sweet.”

A vaccine taken in the mouth could also fend off the virus before it reaches the rest of the respiratory system, though that would depend in part on the size of the droplets, one expert said.

Larger droplets would train defenses in parts of the mouth and throat, while smaller ones would travel further into the body, said Dr Vineeta Bal, an immunologist in India.

Chinese regulators approved the vaccine for use as a booster in September. It was developed by Chinese biopharmaceutical company Cansino Biologics Inc as an aerosol version of the same company's one-shot adenovirus vaccine, which uses a relatively harmless cold virus.

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