Researchers at Radboud University in Nijmegen, the Netherlands, staged a small proof-of-principle experiment, aimed at determining whether exposure to parasites, via insect bites, could vaccinate humans against malaria.

Knowing that humans can develop an immunity to malaria after repeated exposures and that the drug chloroquine kills malaria parasites in the late stages of infection, the researchers divided 15 subjects into two groups. They exposed the first group, periodically, to parasite-bearing mosquitoes and treated them with chloroquine. The second group, the researchers also treated with chloroquine, but didn't expose to the mosquitoes. All the volunteers stopped taking chloroquine and were later exposed to parasite-carrying mosquitoes. No members of the group previously exposed to malaria developed the disease; each member of the comparison group did.

Although it's a far cry from delivering an actual vaccine via insect — and seems more a call for widerspread distribution of antimalarial drugs — it does present the possibility that insects could someday be used to immunize populations against disease. With respect to pandemics like malaria, such a mechanism could be a lifesaver, but it also presents a profound ethical dilemma. The subjects in this test gave their consent to be infected, persons living among vaccine-carrying critters wouldn't have the same luxury.

Mosquitoes deliver malaria 'vaccine' through bites [AP via Slashdot]

INTERPOL had been trying to bust the gang for years, and finally brought in a group of scientists who analyze pollen — forensic polynologists. They tested minute samples of pollen in the counterfeit pills, and discovered the pollen was very specific to a certain region in China.

A study released today in PLoS Medicine explains:

The pollen evidence suggested that at least some of the counterfeit [malaria drug] artesunate came from southern China, and this was supported by examination of the mineral calcite, found in some of the samples . . . Armed with these findings by INTERPOL, Chinese authorities arrested a suspect in China's Yunnan Province in 2006. He is alleged to have traded 240,000 blisterpacks of counterfeit artesunate, enough to "treat" almost a quarter of a million adults with a medicine with no activity against a potentially fatal disease. Whilst the Chinese authorities were able to seize 24,000 of these packs, the remainder are alleged to have been sold at crossings on the border of Yunnan and Myanmar (Burma), accounting for almost a half of all blisterpacks of artesunate sold to the region.

A Collaborative Epidemiological Investigation [PLoS Medicine]