Rochester on the Front Lines to Prevent Bird Flu Pandemic
Tuesday, March 22, 2005
Bird flu is like an extreme example of a new strain of flu.
The Rochester area is again playing a key role in the world’s ongoing fight against infectious diseases. Doctors and nurses at the University of Rochester Medical Center are seeking to enroll 150 people for a study of a vaccine against the most virulent form of bird flu, which has claimed the lives of three out of four people who have been infected with it in Southeast Asia.
The study of 450 healthy people at three sites across the nation is being led by John Treanor, M.D., professor of medicine and director of Rochester’s Vaccine and Treatment Evaluation Unit. The study is being done in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, which is funding the study and preparing for the possibility that the dangerous form of flu could become widespread in people.
The study is evaluating a vaccine made by Sanofi-Aventis and is designed to allow doctors to find the most effective dose to prevent infection. The U.S. government has already purchased 2 million doses of the vaccine and is awaiting the results of the study before deciding how best to formulate the doses.
Bird flu has claimed dozens of lives since the late 1990s. The virus normally infects birds, and in the past few years, millions of chickens and turkeys around the globe, mainly in Southeast Asia, have died or been killed as authorities try to halt the disease’s spread. Most human victims have caught the disease from infected chickens, but a couple of isolated cases appear to have been transmitted from person to person
The risk to people will come if the virus gains a more robust ability to spread from person to person. Since most people have never been exposed to bird flu, they have no immunity to it, and doctors fear the lethal virus could then spread quickly.
“Unlike a typical flu virus, which most people have some immunity against, people have no defense against bird flu,” says Treanor. “The fear is that a bird flu virus that acquired the ability to go from person to person would spread around the globe very quickly.”
Public health officials are concerned because circumstances appear to be similar to those that brought about previous flu outbreaks. In the last century there have been three worldwide flu epidemics, or pandemics, most notably the 1918 outbreak of Spanish flu that claimed an estimated 30 to 40 million lives. Each outbreak was marked by a change in the virus’s outer protein coat, known as the hemagglutinin, which the virus uses to attach to and attack human cells. When that protein has changed, a pandemic has resulted.
The current “regular” form of flu that has been circulating around the world for more than 30 years has both the H1 and H3 protein coats, and the annual flu vaccine protects people against those. But the form of flu sweeping through birds and fowl, and a few people, has an H5 coat. So far the virus has displayed a mortality rate many times that of regular flu and is even more lethal than SARS. A person with bird flu gets the typical symptoms of the virus – painful joints, a headache, a fever, and a cough. Respiratory failure is the most common cause of death.
The experimental vaccine is manufactured very much like traditional flu vaccines. The virus is inactivated and then grown in eggs; it is designed to spur a person’s immune system to fight off the virus.
“Bird flu is like an extreme example of a new strain of flu,” says Treanor. “The components of the flu vaccine change every year depending on what strains are circulating, and this vaccine is no different.
“Based on what we know about other flu vaccines, and what it takes to prevent the flu, we think that using the same type of vaccine, and tailoring it to bird flu, should protect people.”
The study, which is also being carried out at the University of Maryland and the University of California at Los Angeles, will be done in two stages. The first stage will have a total of 113 people, including about 40 in Rochester. They will receive two injections four weeks apart, and their health will be monitored closely so the safety of the vaccine will be assessed.
Once officials have reviewed the safety data, the remaining 337 participants will receive the shots. Most people in the study will get one of four doses of the vaccine; some will receive a placebo. Participants will visit the vaccine unit several times during the seven-month study to have their health monitored and to have blood drawn so that doctors and nurses can check to see if their bodies are making antibodies against bird flu.
Anyone interested in taking part in the study should call 585-273-3990.