Early Studies of Needle-Free Vaccine Delivery System Show Promise

A new pill-sized technology could one day make vaccines needle-free.

Researchers at the University of California at Berkeley studied the new oral delivery method, known as MucoJet, as part of a proof-of-concept study. While the technology has not yet been tested in humans, it was found to be capable of delivering vaccine-sized molecules to immune cells in the mouths of animals.

The hope is that the technology will build immunity cells in the mouth's buccal region and would allow patients to self-administer vaccines.

"The majority of modern vaccines are injected intramuscularly or subcutaneously, but the majority of pathogens actually access the body through mucosal surfaces such as the oral, vaginal and GI tract," said Kiana Aran, PhD, who developed the technology while she was a postdoctoral scholar at Berkeley.

While a few vaccines do use a mucosal route of administration, they use live viral constructs that, according to Aran, could limit their utility and safety.

According to a statement from UC Berkeley, MucoJet works by releasing a jet stream of liquid and immune-system-triggering molecules into the mouth where they penetrate the mucosal layer and trigger an immune response.

MucoJet is described as a 15 mm by 7 mm cylindrical, two-compartment pill-sized device. It device is placed in the inside of the patient's cheek and delivers its contents with pressure, much like that of a water flosser. The pressure is delivered when the exterior compartment of the MucoJet, which holds water, and the interior compartment, which holds both a vaccine solution and a dry chemical propellant, are clicked together. The vaccine solution is then ejected and is able to penetrate the mucosal layer of the buccal tissue. "The results from our studies indicated that we could awaken the immune cells by physical stimuli, in this case pressure, rather than using toxic agents or live viruses," said Aran, who now works as an assistant professor at the Keck Graduate Institute in Claremont University, Claremont, CA.

She said the technology may lead to the development of safer vaccines at a time when safe vaccination has become a concern for some families.

Researchers tested MucoJet first in a laboratory setting using plastic dishes with mucosal layers and buccal tissue from pigs. The researchers evaluated whether they'd be able to use the device to deliver ovalbumin, an immune-stimulating protein, across the mucosal layer. They found that when MucoJet was used there was an eightfold increase in the delivery of ovalbumin, compared to using a dropper to administer the protein.

In a later study, they tested whether MucoJet could deliver ovalbumin to buccal tissue in rabbits. Again, data showed that the delivery system significantly increased the delivery of the protein compared to droppers. Blood tests also showed that rabbits who were treated by MucoJet had key antibodies in their blood that were three orders of magnitude higher than rabbits who received the protein via a dropper.

While it's still unclear what kind of impact the device could have on humans, researchers plan to move forward with testing the device on larger animals, such as monkeys or pigs, who have mucosal tissues more similar to humans