Skip Navigation
A More Perfect Union
Illustrations by Brad Yeo

A More Perfect Union (continued)

Hunch to Bench to Vaccine

One of the questions that epidemiology answers is, “Who is at risk?” After epidemiologists identify risk factors and biomarkers for a disease, basic scientists try to understand the mechanisms behind the markers. They “go molecular” to answer the questions, “What is going on in the cells and tissues?” and “How does that mechanism work?”

“Cervical carcinoma is a beautiful example of this,” says Diane Griffin, MD, PhD, the Alfred and Jill Sommer Professor and Chair of the W. Harry Feinstone Department of Molecular Microbiology and Immunology (MMI). “Epidemiology identified that having a particular infection was a risk factor for cervical cancer, and basic science is helping us to understand it.”

Cervical cancer is the most prevalent form of cancer among women in developing countries. According to Keerti Shah, MD, DrPH ’63, MPH ’57, an MMI professor, clinicians have suspected for more than 100 years that there might be a connection between cervical cancer and a sexually transmitted infection; the cancer seemed most prevalent in women who had many sexual partners.

In the late 1980s, Shah was approached by two epidemiologists who were looking for a virologist who could help them link a human papillomavirus (HPV) to cervical cancer.

The meeting led to a long and productive collaboration. Building on work by German scientist Harald zur Hausen, who won the 2008 Nobel Prize in Medicine for his work in cervical cancer, and using new recombinant DNA technology, Shah and his collaborators conducted comprehensive epidemiologic studies that established the relationship between HPV and the cancer. They published a paper that proposed the causal relationship, and seven years later, Shah and colleagues had proven that nearly all cervical cancers—in all parts of the world—are caused by HPV. Furthermore, they showed that cervical cancer is caused solely by a virus.

The current translation of these discoveries is a mass intervention, an HPV vaccine that will prevent the cancer-inducing infection.

Resisting Malaria

In the battle against malaria, which kills more than one million people every year, resistance is an important consideration, and it wants molecular solutions, says Griffin, founding director of the Johns Hopkins Malaria Research Institute (JHMRI).

One of the strategies for protecting human populations against malaria is to kill the mosquitoes that transmit the malaria parasite to humans. For this work there is insecticide. But what happens when the mosquitoes become resistant to that insecticide? More malaria. Using molecular population genetics, microbiologists at JHMRI are studying ways to overcome insecticide resistance.

Also vexing in malaria work is the incidence of resistance to drug therapies. Ideally, antimalarial drugs restore health to a malaria-infected person by killing the Plasmodium parasites in his body. For decades chloroquine was a very effective treatment against malaria. However, the parasite has developed a widespread resistance to that drug, and there are reports of resistance to newer artemisinin-based antimalarials. To build a better drug, basic scientists at JHMRI are at work now to better understand what happens inside the cells when antimalarial drugs are resisted.

And then there are transgenic mosquitoes, insects that have been exquisitely engineered by scientists to resist infection by the parasite. MMI professor Marcelo Jacobs-Lorena, associate professor George Dimopoulos and assistant professor Jason Rasgon are involved in Plasmodium-resistant mosquito research (see related story). Ideally, the modified mosquitoes would not only survive in the wild but replace the wild-type mosquitoes because of a selective advantage.

design element
Online Extras

Influenza: Past, Present, and Future

Influenza: Then and Now

Tour the 20th century’s great pandemics with Bloomberg School virologist Andrew Pekosz—and learn how the latest H1N1 compares with them.

Listen Now

Talk to Us

Amazed? Enthralled? Disappointed? We want to hear from you. Share your thoughts on articles and your ideas for new stories:

Download the PDF

Get a copy of all Feature articles in PDF format. Read stories offline, optimized for printing.

Download Now (8.7MB)