The vaccine, which is in the works at St. Jude Children's Research Hospital in Memphis, Tenn., was tested on nine healthy adults (two men and seven women with an average age of 28 years). It was developed from a virus closely related to the human form of the lung infecting virus.
In the study participants received a series of three doses of the vaccine. Each vaccine dose was given as an increasingly higher dose, with no significant reactions seen.
The vaccine is being tested in phases: adults first, children second, and, lastly, babies, who are the vaccine's ultimate target group.
Kids won't have to flinch for this vaccine. It's given by nose drops -- a kinder, gentler method than injections.
Croup is a childhood lung disease, which causes nearly 30,000 hospitalizations each year and many more emergency room visits. It is most commonly caused by a virus called the human parainfluenza virus-type 1, or "hPIV-1."
The vaccine doesn't actually contain hPIV-1. Instead, it uses a live yet weakened Sendai virus, which is found in mice and is close enough to hPIV-1 to mobilize the right infection-fighting antibodies and immune responses to fight croup.
The vaccine's developers say that because the vaccine uses a live virus to induce an immune response and protection they expect it to have a durable effect.
They also note that they do not expect any problems from the Sendai virus. There has never been a confirmed case of Sendai infection in humans, "despite abundant contact between mice and children," write researcher Karen Slobod, MD, of the infectious diseases department at St. Jude Children's Research Hospital, and colleagues.