Malaria parasites in vaccinated laboratory mice evolve and become more virulent, according to research at Penn State University. The mice were injected with a critical component of several candidate human malaria vaccines that now are being evaluated in clinical trials. "Our research shows immunization with this particular type of malaria vaccine can create ecological conditions that favor the evolution of parasites that cause more severe disease in unvaccinated mice," said Andrew Read, Alumni Professor of Biological Sciences at Penn State.

"We are a long way from being able to assess the likelihood of this process occurring in humans, but our research suggests the need for vigilance. It is possible that more-virulent strains of malaria might evolve if a malaria vaccine goes into widespread use," Read said. The research, which is published in the 31 July 2012 issue of the scientific journal PLoS Biology, showed that more-virulent malaria parasites evolved in response to vaccination, but the exact mechanism is still a mystery. It was not due to changes in the part of the parasite targeted by the vaccine. Images and more information are online at
http://www.science.psu.edu/news-and-events/2012-news/Read7-2012.

In the war between drugs and drug-resistant diseases, is the current strategy for medicating patients giving many drug-resistant diseases a big competitive advantage? A research paper that will be published in the Proceedings of the National Academy of Sciences argues for new research efforts to discover effective ways for managing the evolution and slowing the spread of drug-resistant disease organisms. The research is led by Andrew Read, professor of biology and entomology and director of the Center for Infectious Disease Dynamics at Penn State University.

The ultimate goal is to develop a new science-based model for drug-resistance management that will inform treatment guidelines for a wide variety of diseases that affect people, including malaria and other diseases caused by parasites, MRSA and other diseases caused by bacterial infections, AIDS and other diseases caused by viruses, and cancer.

Discovery of a key red cell molecule used by the malaria parasite gives renewed hope for an effective vaccine in the future, according to an international team of researchers. Plasmodium falciparum, a blood parasite that causes malaria by invading and multiplying in the red blood cells, kills 1 to 2 million people annually.

A nearly $1.9 million grant from the National Science Foundation is enabling a Penn State-led group of researchers to continue studies on the potential effects of climate change on the spread of infectious diseases, such as malaria and dengue. The grant is part of federal stimulus funding authorized under the American Recovery and Reinvestment Act.

Targeting older mosquitoes may be the best way to fight the global scourge.

Temperature is an important factor in the spread of malaria and other mosquito-borne diseases, but researchers who look at average monthly or annual temperatures are not seeing the whole picture. Global climate change will affect daily temperature variations, which can have a more pronounced effect on parasite development, according to a Penn State entomologist."We need higher resolution environmental and biological data to understand how climate change will affect the spread of the malaria parasite," says Matthew Thomas, professor of entomology. We need to understand temperature from the point of view of the mosquito."