March 2, 2000 (Minneapolis) -- There's good news for developing countries still battling measles. Delivering a booster of the measles vaccine through an aerosol spray may be as effective and safer than giving injections, according to a report from South African researchers in this week's issue of the journal The Lancet.
"The aerosol route of administration ... is particularly suited to mass immunization campaigns because of its cost-effectiveness," lead author Athmanundh Dilraj tells WebMD. He adds that it is quick and easy to administer by workers with limited medical training. Dilraj is a senior research scientist and PhD candidate at the Medical Research Council in Durban, South Africa.
In this study, more than 4,300 children ranging from 5 to 14 years old received one of two different strains of measles and received the vaccines by either injection or aerosol spray. After following the children for one year, they found that the aerosol was the most effective at building up immunity for one strain of measles. It was less effective at building up immunity for another strain of the disease.
However, there may be a difference in response by ethnicity, the authors write. Children of Indian descent had a better response to the aerosolized vaccine than African children.
One observer agrees. "An aerosol delivery of booster doses of the measles vaccine is promising in the developing world," says Edgar K. Marcuse, MD, a pediatrician with an interest in immunization at Children's Hospital and Medical Center in Seattle. However, for parents in the U.S. who may be hoping to spare children the discomfort of the measles booster often required before entry into middle school or junior high, these findings have limited relevance because the injected vaccines used in this trial are not those currently in widespread use in the U.S., Marcuse tells WebMD. He is professor of pediatrics at the University of Washington.
Caused by a virus, measles is a common contagious disease most often seen in childhood. Symptoms include mild to high fever, harsh cough, runny nose, red eyes, sneezing, and tiny white spots on gums or inside cheeks. These symptoms are generally followed by the typical measles rash, which spreads from the face downward to the arms and legs, and peeling skin.
The measles vaccine is usually given by injection as part of the combined MMR (measles, mumps, and rubella) vaccine between the ages of 12 to 15 months old. A second "booster" dose of MMR is usually given when the child is between ages 4 and 6, and starting school.
"We're a long way from recommending routine aerosol booster doses," says Marcuse. "While this delivery system was effective with one strain, it clearly had difficulty with the other in the study. We need to understand why Indian and African children had different response rates." He also notes that giving the vaccine through an electric device, like those used in the study, would restrict its use in rural areas.
- South African researchers say the aerosol form of a measles booster, which they tested in more than 4,300 children, may one day be used to immunize children in developing countries.
- The researchers say aerosol versions of the vaccine are easy for people to administer, may work as well as injected versions without the needle's risk of infection, and it is inexpensive.
- Observers note that this aerosol vaccine may not be appropriate in the U.S. because the injected vaccines used in this trial are not those currently in widespread use in the U.S. Also, experts say it will probably be a long time before they can recommend aerosol boosters because there seem to be different rates of effectiveness according to the race of the child receiving it and which strain of vaccine is delivered.