Easy-to-use nasal anthrax vaccine offers strong protection in animal studies

ANN ARBOR, MI – A vaccine against anthrax that is more effective and easier to administer than the present vaccine has proved highly effective in tests in mice and guinea pigs, report University of Michigan Medical School scientists in the August issue of Infection and Immunity.

The scientists were able to trigger a strong immune response by treating the inside of the animals’ noses with a “nanoemulsion” – a suspension of water, soybean oil, alcohol and surfactant emulsified to create droplets of only 200 to 300 nanometers in size. It would take about 265 of the droplets lined up side by side to equal the width of a human hair.

The oil particles are small enough to ferry a key anthrax protein inside the nasal membranes, allowing immune-system cells to react to the protein and initiate a protective immune response. That primes the immune system to promptly fight off infection when it encounters the whole microbe.

Besides eliminating the need for needles, the nanoemulsion anthrax vaccine has another advantage, the researchers say: It is easy to store and use in places where refrigeration is not available.