Nurse Lea Ann Johnson examines patient Jared Burlison, 6, in his Mt. Juliet Home. Burlison is taking part in a study of a new RSV vaccine. (photo by Dana Johnson)
Cystic fibrosis patients test investigational RSV vaccine
Healthy children who contract respiratory syncytial virus (RSV), the most common cause of childhood lower respiratory tract infections, are occasionally hospitalized due to bronchiolitis and its after-effects. Bronchiolitis results in nasal discharge, coughing and wheezing.
Children with Cystic Fibrosis are at an even greater risk when RSV strikes.
A Vanderbilt University Medical Center study is testing an investigational vaccine for RSV in 17 Vanderbilt Cystic Fibrosis patients, ages 1 to 13.
There are no FDA-approved vaccines against RSV at present, but Vanderbilt University Medical Center has been testing vaccines for RSV for the past several years. One of the vaccines is being tested at VUMC, one of 18 centers participating in a study to see whether the vaccine will decrease the chances of 289 participating CF patients of developing serious RSV infections over the next few months.
The vaccine is made from one of the outer proteins of RSV called the fusion protein. It is the third investigational vaccine made from this protein. All three versions have been tested in humans. This particular vaccine has been tested in healthy adults prior to this study.
"We know that viral infections frequently precede lower airway bacterial infections in our patients so our goal is to see if we can prevent this particular viral infection," said Dr. Christopher E. Harris, assistant professor of Pediatrics. "It's very similar to what we do with the flu vaccine — giving the flu vaccine in the fall to prevent flu and subsequent bacterial lung infections."
Harris said the most serious problem that occurs when CF patients have RSV is the damage to the airway that can occur as part of a viral infection. This damage makes it more likely that a bacterial infection will occur.
"In CF patients, it is difficult if not impossible to completely clear a bacterial lung infection. It frequently smolders at a low level, comes up to a higher level, then you have to treat it with antibiotics to drop it once again to the lower level," Harris said.
The pediatric patients received either the vaccine or a placebo before the end of November and are now receiving weekly phone calls from Lea Ann Johnson, R.N., M.S.N., CPNP, the study's research nurse. The study will conclude in June.
Johnson calls the families with a weekly list of questions that are geared to find out if the children are showing any signs of a lower respiratory tract infection. If she gets one or two affirmative answers on the questionnaire, Johnson visits the home, school or day care for a brief, physical exam on the patient.
If there are particular signs or symptoms, Johnson uses a nasal wash on the patient to detect RSV.
RSV is characterized by wheezing and causes approximately 90,000 hospitalizations and 4,500 deaths each year in both infants and young children, according to statistics released by the American Lung Association. It takes its greatest toll on children younger than six. It is spread by hand-to-hand contact with any object harboring the pathogen; by contact with the eyes and nose; and by droplets from a cough or sneeze.
It occurs throughout the year, but there are typically widespread outbreaks during the winter months, peaking in January and February. Vanderbilt Children's Hospital is typically full during these months with many of the hospitalizations caused by RSV.
In a phase one study of the drug, the patients had about half as many lower airway infections as normally seen in CF patients.
Harris said the study is an example of how clinical research can reach out to the community and be "user-friendly."
"We found out early on that families really like being in touch with the center every week. It's a way for them to formally keep track of an illness, by being asked the series of questions each week — about their child's cough, runny nose or sore throat."
The study will also evaluate the safety and side effects (such as fever and muscle soreness) of the vaccine.
And it will examine whether the immune system makes antibodies against RSV in children with CF.
In addition to Harris' study, Vanderbilt is investigating several other possible RSV vaccines including live attenuated (weakened) virus vaccines that have been studied for the past several years by Dr. Peter F. Wright, professor of Pediatrics.