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Making needleless vaccines to protect children from infectious diseases

The new technique is cost-effective, making it particularly useful for developing countries
by TR Pakistan

Millions of people are infected with hepatitis B every year. Hundreds of thousands die. And small children are particularly at risk. The World Health Organization’s data shows that nearly 257 million people are infected with hepatitis B. In 2015 alone, 887,000 deaths were attributed to the viral disease.

Due to high cost and stable environmental conditions required for vaccine storage, many people in developing countries are not vaccinated against this dangerous virus. To solve this issue, researchers have been working on cheaper and orally administered vaccines for sometime. However, a sufficiently effective oral hepatitis B vaccine has yet to be developed.

Meanwhile, a joint collaboration among physicists at the University of Copenhagen’s Niels Bohr Institute, researchers from University of São Paulo and São Paulo’s Butantan Institute has led to the introduction of a technique that might lead to an optimal oral Hepatitis B vaccine.

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“We have used a technology commonly used in solid state physics to explore how the vaccine behaves within a particular type of encapsulation. This has yielded crucial information that would not otherwise have been achievable. When we scientists venture beyond our comfort zone and deploy each other’s knowledge across disciplines, entirely new possibilities can emerge,” said Heloisa Bordallo, an associate professor at the Niels Bohr Institute, and one of the two main authors of the research article recently published in the international journal Scientific Reports.

Three dimensional insight
A major challenge of making an oral vaccine is to encapsulate it in a material that can endure the harsh conditions of the human digestive system, to protect the vaccine from being destroyed before it reaches its intended destination in the body. The Danish research team’s collaborative partners in Brazil have long known that the silica-material SBA-15 is well-suited to encapsulate a hepatitis B vaccine. However, they did not know exactly how the material protected the vaccine. Nor were they certain about why their vaccine was not always completely effective.

This is where the team of Danish physicists came into the picture. Using a special technique that combines x-ray and neutron imaging, researchers at the Niels Bohr Institute were able to produce 3D images of the inside of the SBA-15 silica. According to a press release, this marks a crucial step in the use of this technique to develop pharmaceuticals.

The imagery allows researchers to see how the vaccine behaves inside the silica, right down to the particle scale. Among other things, they were able to see that the vaccine had a tendency to clump within the silica, making it less effective.

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“Now we know what makes the vaccine less effective, and how to optimize it. 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,” explained Bordallo.

No swelling and infection
According to the other main author of the paper, Martin K. Rasmussen, a former student at the Niels Bohr Institute and current doctoral student at DTU, this vaccine is particularly promising for developing nations.

“Getting rid of needles being poked into the arms of little children is an advantage in and of itself. It also eliminates any need to sterilize needles and possible side effects such as swelling and infection. And, unlike the vaccine in use today, this type of vaccine needn’t be refrigerated. As such, costs will be reduced and the vaccine’s administration will be eased.”

The researchers hope that the 3D technology will also be used to develop oral vaccines against several other types of disease. The goal of the researchers is to produce a 6-in-1 oral vaccine against diphtheria, tetanus, whooping cough, polio, Hib and hepatitis B. The vaccine against diphtheria and tetanus is already being developed.

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