FDA Teams Prepare for Biological Threats
Carolyn Wilson, Ph.D., is associate director for research at FDA's Center for Biologics Evaluation and Research. In her Bethesda, Md., laboratory, she researches the utility of pig cells, tissues and organs as materials for transplantation in humans.
Zuben Sauna, Ph.D., principal investigator in CBER's hemostasis laboratory, and chemist Wells Wu, Ph.D., are exploring the shapes of proteins used in medical treatments to determine why they prompt a strong reaction from the body's immune system. Suspecting that the shapes may be part of the problem, the researchers are using tiny pieces of DNA-like molecules called aptamers to probe the proteins. Hemostasis is the process of getting bleeding to stop and the antibodies that cling to these proteins are causing life-threatening complications, particularly in the treatment of bleeding disorders.
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Biological threats to public health may occur naturally, such as an influenza (flu) epidemic. Or their origin may be more sinister—an act of terrorism.
Researchers at the Food and Drug Administration's Center for Biologics Evaluation and Research (CBER) are facilitating the development of safe, effective treatments to neutralize these threats.
CBER's role includes the regulation of preventive and therapeutic vaccines, blood and blood products, human cell and tissue-based products, gene therapies and xenotransplantation (a procedure that uses a different species as a source of transplanted materials). Within that role is a mission set forth by FDA in 2011: to advance regulatory science for the development and evaluation of medical countermeasures to threats to U.S. and global health and security. Regulatory science is the foundation of FDA decision-making.
Carolyn Wilson, Ph.D., associate director for research at CBER, notes that CBER's role is not only to pave the way for the development of new treatments, but also to ensure that those treatments are safe and effective.
"Companies are producing very complex biological products," she says. "Our research scientists are trying to identify the crucial characteristics that will indicate that they are both safe (i.e., free of infectious agents, not going to cause cancer, etc.) and that they will have the anticipated clinical benefit."
Wilson says that CBER scientists have been closely monitoring the deadly H7N9 flu virus that emerged in China this year. There have been no cases detected in people or birds in the U.S. but Wilson says, "Our laboratory scientists are taking the steps needed to ensure we are prepared as possible if there is a public health emergency."
Critical materials have been developed to facilitate and support vaccine production, in the event that it is needed.
In addition to its ongoing evaluation of vaccines that target the upcoming flu season, FDA researchers are developing and evaluating alternative approaches to vaccine development to help identify a "universal" vaccine against a broad range of influenza viruses.
"In addition to the work we do to facilitate public health preparedness, we are also heavily investing in research that promotes development of safe, effective and innovative biological products," says Wilson.
In her lab, Wilson studies the presence of a naturally occurring threat—a particular kind of virus called a retrovirus—in pig cells and their potential to infect humans. Live cells, tissues and organs are candidates for use in xenotransplantation.
However, there is a particular retrovirus that occurs in all pigs. Wilson and her colleagues are studying the conditions that affect virus infection and transmission to human cells. Their goal is to prevent transmission to humans. Her laboratory has also developed methods to effectively screen source pigs, human recipients, and the materials taken from pigs for transplantation into a human patient.
Other research teams within CBER are taking different paths towards the goal of developing safe, effective vaccines and other treatments for a range of clinical needs, ranging from naturally occurring and human-generated biological hazards to cancer, diabetes, and cardiovascular disease, among others. Their work includes:
- Studying the interaction between humans and three disease-causing bacteria: Bordetella pertussis (causes whooping cough), Bacillus anthracis (causes anthrax, an acute, potentially deadly infection) and Staphylococcus aureus (causes skin disease, blood poisoning and toxic shock syndrome). In order to develop new vaccines and treatments for these diseases, the research team is studying the bacterial conditions needed for infection and the immune system responses that protect against disease.
- Working to better understand the role of glycoconjugates—carbohydrates bonded to either a fat molecule or a protein—in bacterial infections. Glycoconjugate-based vaccines have been found to help protect against meningitis, pneumonia and blood infections, and researchers hope to develop new vaccines.
- Studying a major problem with the body's reaction to protein-based medical treatments, which tend to trigger an unwanted immune system response. Antibodies bind to the proteins and cause potentially life-threatening complications, particularly in the treatment of bleeding disorders. One of the issues they are considering is whether the proteins in these treatments have shapes that trigger antibody production.
In a tour of CBER labs, the words "next generation" are frequently used by scientists working on vaccines and innovative testing methods. "We don't want to wait for a threat to arrive on our doorstep," says Wilson. "We need to be—and we are—proactive."
This article appears on FDA's Consumer Updates page, which features the latest on all FDA-regulated products.
September 24, 2013