Investigators have advanced their understanding of how to create an oral-delivery mechanism for the hepatitis B virus (HBV) vaccine. The injectable vaccine is relatively expensive, in part because of the complexities of its storage and transportation, since it must remain refrigerated. Consequently, the development of a cheaper, more easily transportable oral version would greatly facilitate the vaccine’s distribution in developing nations, where the need is great.

Publishing their findings in Scientific Reports, researchers studied how the HBV vaccine behaves when encapsulated in a material known as SBA-15. Previous research has indicated that SBA-15 is a promising form of encapsulation for the vaccine, likely able to help protect it against the digestive system and prevent it from being destroyed before it can impact the immune system.

The investigators wanted to figure out how the material managed to protect the vaccine and why it sometimes appeared to compromise the vaccine’s effectiveness. So they developed 3-D images of the inside of the SBA-15 silica with a method that combines X-ray and neutron imaging, allowing them to study the behavior of the vaccine within. They found that the vaccine tended to clump up, which compromised its effectiveness.

“Now we know what makes the vaccine less effective and how to optimize it,” Heloisa Bordallo, PhD, an associate professor at the Niels Bohr Institute in Copenhagen,and one of the two main authors of the study, said in a press release. “We know exactly how much vaccine should be put in the silica capsule for it to work best in the body, and the clinical trials can be better interpreted.”

The researchers are attempting to develop an oral vaccine containing six vaccines, including diphtheria, tetanus, whooping cough, polio, Hib and HBV. They have already begun developing those for diphtheria and tetanus.

To read a press release about the study, click here.

To read the study, click here.