Nano vaccine for hepatitis B can be boon for Third World

August 13th, 2008 - 3:19 pm ICT by IANS  


Washington, Aug 13 (IANS) A modern day scourge like chronic hepatitis-B infects 400 million people worldwide and claims a million lives every year, even with the availability of three effective vaccines. In many poor countries, refrigerated conditions required for storing vaccines are costly and scarce, not to speak of keeping needles and syringes sterile. The need to have people return for the three shots currently required also limits success.

Now, a new vaccine that avoids these drawbacks has moved a step closer to human trials. Researchers hoped it will help immunise large numbers of children and adults in Africa, Asia and South America, efficiently and safely.

The study suggested that the new type of vaccine would not require cold storage and require fewer shots than current vaccines. For instance, protective immunity with the new vaccine required only two immunisations in animals.

Scientists at the Michigan University Nanotechnology Institute for Medicine and Biological Sciences reported that a novel, needle-less method for getting an immunity-stimulating agent into the body has proved non-toxic and able to produce strong, sustained immune responses in animal studies.

The vaccine is based on a super-fine emulsion of oil, water and surfactants placed in the nose. The nanoemulsion represents a new delivery method for an antigen already used in existing hepatitis B vaccines to activate the body’s immune defences.

“Our results indicate that needle-free nasal immunization, using a combination of nanoemulsion and hepatitis B antigen, could be a safe and effective hepatitis B vaccine, and also provide an alternative booster method for existing vaccines,” said James R. Baker, Jr., the study’s co-author and director of the institute.

The nanoemulsion is made up of soybean oil, alcohol, water and detergents emulsified into droplets less than 400 nanometres. It also avoids temporary pain and redness that results from a shot of current vaccines.

Baker’s team has published earlier studies affirming the promise of nasal nanoemulsions for smallpox, influenza, anthrax and HIV vaccines.

The findings appear online in tPLoS ONE.

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