Joined: 16 Mar 2004
|Posted: Fri Sep 05, 2008 3:35 pm Post subject: Vaccines may Boost Immune Response against Smallpox and HIV
|Nanoemulsion Vaccines may Boost Immune Response against Smallpox and HIV
Researchers at the University of Michigan Health System say that the body’s immune response against smallpox and HIV may be boosted with the help of a novel vaccination technique, wherein an oil-based emulsion is placed in the nose rather than needles. The researchers say that their proposition is based on the findings of two studies, which build on the previous success in animal studies with a nasal nanoemulsion vaccine for influenza they reported in 2003.
Nanoemulsion vaccines are based on a mixture of soybean oil, alcohol, water and detergents emulsified into ultra-small particles about 1/200th the width of a human hair. They are combined with the disease-causing microbes to trigger the bodys immune response. The University of Michigan was recently awarded a patent for the technology pioneered by its scientist Dr. James Baker Jr.
Nanoemulsion mechanism of action against microbes
The two studies show the nanoemulsion platform is capable of developing vaccines from very diverse materials. ‘We used whole virus in the smallpox vaccine. In the HIV vaccine, we used a single protein. We were able to promote an immune response using either source’, says Baker. He says that the surface tension of the nanoparticles disrupts membranes and destroys microbes, but it does not harm most human cells due to their location within body tissues.
Baker also says that nanoemulsion vaccines are highly effective at penetrating the mucous membranes in the nose, and at initiating strong and protective types of immune response. The researcher believes that the smallpox results in mice, reported in the journal Clinical Vaccine Immunology, may pave the way for an effective human vaccine against smallpox that is safer than the present live-vaccinia virus vaccine, as it will use nanoemulsion-killed vaccinia virus. He says that the nanoemulsion vaccinia vaccine may offer protection equal to that of the existing vaccine, without the risk of using a live virus or the need for an inflammatory adjuvant such as alum hydroxide. ‘We found that the nanoemulsion vaccine could inactivate and kill the virus and then subsequently induce immunity to the virus that includes cellular immunity, antibody immunity and mucosal immunity’, Baker says.
Nanoemulsion Mechanism of Action Against Spores.
When Bacillus spores contaminate a mucosal membrane, nutritional factors present in the damaged tissue and serum serve as germination enhancers.
These germination enhancers initiate the germination of the bacillus spores.
The tough outer shells of the spores then become vulnerable to the lethal effect of the nanoemulsion. This will result in disruption of the spore.
In another study on mice, published in the journal AIDS Research Human Retroviruses, Baker's team has reported that a nanoemulsion vaccine may also be effective in preventing HIV infections. The researchers pointed out that evidence was growing that HIV virus could can infect the mucosal immune system, an area where nanoemulsion vaccines ability to provide mucosal immunity could hold importance. Therefore, 'developing mucosal immunity may be very important for protection against HIV', Baker says, adding that previous vaccine approaches have not aimed to do that.
The researchers are now planning further research to test the concept in animal models, potentially with whole viral vaccines or ones with multiple protein components.