The product, known as Convidecia Air, delivers a dose of vaccine through a puff of air from a nebulizer which is then inhaled through the mouth. CanSino’s Convidecia Covid-19 injected vaccine is already in use in China and has been approved in a handful of other countries.
Inhaled shot clearance, which the company said needed to complete additional steps before going to market, comes as several Chinese cities enforce large-scale Covid lockdowns and mass testing campaigns in response to small-scale outbreaks.
China continues to adhere to a strict zero-Covid policy, even as the rest of the world learns to live with the virus. Pressure on officials to bring outbreaks under control is mounting ahead of a twice-a-decade political meeting next month, where Chinese leader Xi Jinping is expected to break with tradition and begin a third term.
A low vaccination rate among the elderly is one of the medical reasons cited by Chinese authorities for the ongoing disease control measures.
Meanwhile, new variants of the coronavirus have impacted the protection offered by first-generation vaccines around the world, including Chinese vaccines that offer less robust antibody protection than mRNA vaccines developed in the West.
Booster and vaccination campaigns – and the development of next-generation products – are underway in China as the country seeks to boost protection.
University of Hong Kong virologist Jin Dong-Yan, who was not involved in the development of the vaccine, said it was difficult to say what impact the product would have if used in China because more data were needed to understand the protection it provides. , including against infections.
However, injections that could offer so-called mucosal immunity by being given through the nose or mouth could be a good option for use as extra boosters in China, Jin said, given the low levels of natural immunity in China. its population, where only a small fraction of people have had Covid.
Studies have indicated that people infected with Covid acquire this type of immunity, which is not central to the protection of injected vaccines.
“These (types of vaccines) could be particularly important for China, because all over the world, in the general population, we have a mixed type of immunity (both from vaccination and from natural infection) … and (these vaccines) might be similar to natural infection in terms of inducing mucosal immunity,” he said, adding that real data was needed to confirm this.
“Different types of (second-generation) vaccines should be researched and developed to help boost herd immunity in the general population, which is a big problem (for) China,” he said.
The manufacturer did not provide data to support these claims, but referred to studies in the medical journal The Lancet.
In a small study published in August, CanSino researchers reported that in people who received two injected doses of the CoronaVac vaccine, a booster of the inhaled vaccine increased antibody levels compared to a third injected dose of CoronaVac.
CoronaVac, a vaccine developed by Beijing-based Sinovac widely used in China and around the world, uses a different type of technology from Convidecia, so the inhaled dose provided a heterologous, or mix-and-match, boost. .
The study did not test whether the inhaled dose prevented people from becoming infected or prevented them from transmitting Covid to others.
Globally, drugmakers are racing to make next-generation vaccines that can improve protection against Covid, including those that use innovative dose delivery methods.
Clinical trials are underway to test more than a dozen spray vaccines to see if they can create mucosal immunity. This stimulates certain antibodies in the nose and mouth, particularly in an effort to prevent an infection from taking hold in the first place.
There is hope that these non-injected vaccines, which are given as drops, sprays or tablets in the mouth and nose, may also prevent the infection from spreading from person to person. – what injected vaccines don’t do very well after new variants of the virus emerge.
CanSino’s Convidecia vaccine is similar to the Johnson & Johnson and Oxford AstraZeneca vaccines. It uses a harmless virus called an adenovirus to transmit instructions for making Covid spike proteins into cells so the body can create antibodies against them.
None of CanSino’s products have been cleared in the United States, but the World Health Organization earlier this year listed the injected version of Convidecia for emergency use.