A group of immunologists from the Chinese Academy of Sciences (CAS) have reportedly developed a “super-small” inhalable vaccine that could provide better protection against viral infections than conventional injectable vaccines.
A single dose of the aerosol-propelled drug delivers microscopic 2.8 micron-thick particles that produced a sustained immune response in several lab subjects, including mice, hamsters and monkeys, according to an article published by the South China Morning Post.
The CAS team said it attempted to replicate how ultra-fine pollutants known as respirable suspended particulates (RSPs) find their way into our system. The microscopic pollutants are typically created by the combustion of fossil fuels like wood and coal and are known to be harmful to humans and animals when inhaled.
Prolonged exposure to RSP measuring close to 2.5 microns thick is responsible for several potentially life-threatening cardiovascular and respiratory conditions, according to the Environmental Protection Agency.
To develop an aerosol-based vaccine that utilises the same pathways as RSPs, the CAS team inserted 20-nanometer-wide Covid-19 antigens inside porous microcapsules measuring just 10 nanometres in diameter and then freeze-dried them, shrinking the microcapsules to just 2.8 microns thick.
The breakthrough vaccine allows the drug to reach the lungs directly, making for a significantly more efficacious delivery mechanism, said CAS Institute of Process Engineering researcher and co-author of the team’s paper, Ye Tong, speaking with Science Times.
Injectable vaccines do not provide adequate protection in the respiratory tract, failing to produce enough antibodies or a mucosal immune response in the subject compared to his team’s aerosol-based alternative, according to Ye.
Depositing the vaccine deep inside the lungs facilitated a more prolonged release of the medicine inside the subject, lasting up to 42 days when inhaled, and only five days when injected.
The team observed that the aerosol-based vaccine prevented more host-to-host transmissions than their more-traditional counterparts.
Unlike injectable Covid-19 vaccines, the super-small inhalable alternative can remain stable at room temperature for a month and does not require cold storage – making it significantly easier to deliver to remote and rural locations.
Ye and his team also mentioned that the general population is more likely to favour inhalable drug administration than having an injection, which could substantially boost total vaccination rates amongst the population.
The CAS team says it is hopeful their novel delivery mechanism has potential and has already set its sights on researching how to create an inhalable chemotherapy drug.