New antibody to prevent respiratory syncytial virus in premature babies

Virginia Commonwealth University researchers are studying the effectiveness of introducing a new antibody in premature infants to manage the most common form of lower respiratory tract infections in children worldwide.

Respiratory syncytial virus, RSV, which is most common during the winter months, is the leading cause of pneumonia and bronchitis in premature infants. Lower respiratory infections account for more than 125,000 pediatric hospitalizations a year in the United States.

The VCU School of Medicine’s Department of Pediatrics is one of about 100 sites across the country expected to enroll a total of 6,000 children under age 2. The phase III clinical trial will examine the safety and efficacy of a new anti-RSV molecule.

“Premature infants are at greatest risk for developing RSV because their lungs are not fully developed,” said Linda D. Meloy, M.D., associate professor and interim chair of general pediatrics and emergency medicine. “They also have great difficulty clearing the nasal secretions caused by the virus and recovery from the infection can be complex.”

Meloy, who is the primary investigator of the study at VCU, said VCU hopes to enroll about 50 participants and those who are at greatest risk for developing the virus will be the primary targets for recruitment.

“Researchers have been working hard to develop new antibodies with increased potency, patient compliance and efficacy to help prevent serious lower respiratory tract infections in pediatric patients at high risk for RSV,” said Meloy. Other factors that increase an infant’s risk of RSV include chronic lung disease and congenital heart disease.

The primary course of prevention against RSV is with the antibody palivizumab, which is administered through injection. Researchers will compare palivizumab with the new anti-RSV molecule to determine which one is more effective in preventing RSV in premature infants. The new anti-RSV molecule may be 50 to 100 times more effective than palivizumab in preventing RSV, said Meloy.

“Premature infants do not have enough antibodies in their systems to fight off the infection with RSV,” explained Meloy. “Administering antibodies to these infants enables them to fight off the infection with RSV and have milder symptoms.”

Participants will be given monthly injections of either the new anti-RSV molecule or palivizumab starting in late October and will receive the injections until April 2005. Each injection will protect the infant for approximately 30 days. Researchers will be testing nasal secretions for RSV throughout the course of the study.

RSV may play a major role in the development of asthma and chronic obstructive pulmonary disease. It is transmitted through casual contact and is spread through the air via coughs and sneezes. RSV symptoms include excessive nasal secretions, wheezing and rapid breathing accompanied by a fever.