by Will SansomEvery winter, a formidable enemy rises up to threaten the lungs of the most vulnerable members of humanity. This enemy steals the breath of premature babies whose lungs are not fully developed, and the air of infants and senior adults with weak immune systems. This frightful enemy of the wind is RSV, respiratory syncytial virus.
No active vaccine exists to prevent RSV infection, nor is there a medication proven to counter RSV illness after it begins. Hospitals stabilize tiny RSV-infected patients with oxygen (through ventilators if necessary) and fluids. Most infants recover, but recent studies indicate they are at higher risk for asthma and apnea later in life.
Thatís what makes the research of Santanu Bose, Ph.D., so important. Dr. Bose, assistant professor of microbiology and immunology, studies the instinctive response of lung cells to RSV. He is focusing on protective antiviral molecules that are produced in the lung cells in response to the infection.
"Itís like an intruder in a house in a subdivision," Dr. Bose says. "The intruder wants to go from house to house, but if someone in the first house escapes and goes to other houses to tell them something is wrong, the other homeowners are alerted. The others will naturally arm themselves to defend their homes. In terms of response to RSV, I am trying to understand the alert system and the defensive arsenal of the cells."
Understanding this response could lead to a medication to effectively treat RSV, which can be spread by sneezing or coughing. "We have no active vaccine at this point, but we do have two products that protect at-risk infants by providing them with antibodies against RSV," says Charles Leach, M.D., professor of pediatrics. "These shots are administered every month for five months. We give these to babies who have chronic lung disease, who are premature or who have significant congenital heart disease. We usually start in October, about a month before RSV season hits."
RSV infection may result in pneumonia, bronchiolitis (inflamed bronchial tubes) and croup. Symptoms include fever, coughing and wheezing. "Youngsters are admitted for RSV throughout the winter months," Dr. Leach says. "A lot of times, these children must be placed on mechanical ventilators to help them breathe. For some children, the RSV infection can be severe or even fatal."
Mackenna Bittleís physician and parents werenít about to let that happen to the blonde-haired cutie, who was born nine weeks early with a heart condition. Mackenna received the series of antibody injections for two winters. The injections are $1,500 apiece for younger babies and $3,000 for older babies over 20 pounds. "She didnít come down with RSV, so it was worth it," said Jennifer Bittle, her mother.
Morgan Estes, born eight weeks early, has been hospitalized twice for allergy-induced asthma. She, too, had the antibody injections. "Most medical offices donít offer them," said Morganís mother, Michelle Estes. "They must be given every 28 days religiously to work. You have to look carefully at holidays and vacations and make sure you can get the shot. Morgan would have been so much worse off to have RSV on top of the allergy-induced asthma."
RSVís connection to asthma is only poorly understood. "Clearly the link with reactive airway disease is there, but it is the old chicken-and-the-egg question," Dr. Leach says. "Because they contracted RSV, does that make them more prone to developing asthma as they get older, or is it their propensity for asthma that makes them contract RSV infection serious enough to warrant hospitalization?"
Most RSV disease is treated on an outpatient basis. Only one in 100 RSV-infected patients is hospitalized, usually because of respiratory distress. Studies examining the relationship with asthma have been done in the patients requiring hospitalization.
"RSV changes the way the immune system develops in many infants and toddlers," says Stephen Inscore, M.D., associate professor of pediatrics. "Though most cases resolve by the time a child is school-age, a good number never resolve. RSV in adults and older children presents as a mild cold illness, but to the young infant, RSV has devastating consequences."
Dr. Bose points out the challenge of developing a vaccine against RSV. "A vaccine causes the body to remember that the virus is an invader of foreign origin," Dr. Bose says. "But RSV is so smart that it causes the body to have a kind of amnesia, and not remember prior infections."
Dr. Boseís research has placed the Health Science Center on the front lines of the war with the enemy of the wind. What he finds might help the Bittles, the Estes and other families to breathe a little easier.
How common is RSV?
Source: American Lung Association
UT Health Science Center
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